Automotive Technology A Systems Approach Canadian 3rd Edition Erjavec Solutions Manual by Ace Test Banks

Automotive Technology A Systems Approach Canadian 3rd Edition Erjavec Solutions Manual

richard@qwconsultancy.com

1|Pa ge

Table of Contents Section 1: Automotive Technology ................................................................................. 1-1 Section 2: Engines............................................................................................................ 2-1 Section 3: Electricity ........................................................................................................ 3-1 Section 4: Engine Performance ........................................................................................ 4-1 Section 5: Manual Transmissions and Transaxles ........................................................... 5-1 Section 6: Automatic Transmissions and Transaxles....................................................... 6-1 Section 7: Suspension and Steering Systems ................................................................... 7-1 Section 8: Brakes.............................................................................................................. 8-1 Section 9: Passenger Comfort .......................................................................................... 9-1

iii

Preface This Instructor’s Manual is intended to complement Automotive Technology: A Systems Approach, Third Canadian Edition, by Jack Erjavec, Martin Restoule, Stephen Leroux, and Rob Thompson. This Instructor’s Manual was adapted by Dean Key. It is organized according to the textbook sections and by chapter and includes the following features to assist instructors in organizing and preparing for lectures: • • • • • • •

Chapter Overview Learning Outcomes Instructional Outline with Teaching Hints Additional Teaching Hints Common Student Misconceptions and Stumbling Blocks Shop Activities and Case Studies Suggested Answers to Textbook Review Questions

Additional Teaching Resources Additional teaching aids are available from Nelson Education in support of this textbook for teaching Automotive Technology in Canadian colleges and universities. The following supplements are available on the password-protected Faculty Resources web page at http://www.nelson.com/automotivetechnology3Ce: •

NETA Assessment: The Test Bank was written by Krystyna Lagowski. It includes over 1000 multiple-choice questions written according to NETA guidelines for effective construction and development of higher-order questions. Also included are 500 true/false questions, 500 completion questions, and 430 short answer questions. Test Bank files are provided in Word format for easy editing and in PDF format for convenient printing whatever your system. The NETA Test Bank is available in a new, cloud-based platform. Testing Powered by Cognero® is a secure online testing system that allows instructors to author, edit, and manage test bank content from any place with Internet access. Nelson Testing Powered by Cognero for Automotive Technology can be accessed through http://www.nelson.com/login and http://login.cengage.com. Printable versions of the Test Bank in Word and PDF formats are available with the Instructor Resources for the textbook.

•

NETA Presentation: Microsoft® PowerPoint® lecture slides for every chapter have been created by Martin Restoule, Algonquin College. There is an average of 50 slides per chapter, many featuring key figures, tables, and photographs from Automotive Technology: A Systems Approach.

•

MindTap for Automotive Technology is a personalized teaching experience with relevant assignments that guide students to analyze, apply, and elevate thinking, allowing instructors to measure skills and promote better outcomes with ease. A fully online learning solution, MindTap combines all student learning tools—readings, multimedia, activities, and assessments—into a single Learning Path that guides the student through the curriculum.

•

Instructors personalize the experience by customizing the presentation of these learning tools to their students, even seamlessly introducing their own content into the Learning Path. Instructors can access the MindTap for Automotive Technology at http://www.nelson.com/login and http://login.cengage.com. •

Image Library: This resource consists of digital copies of figures, short tables, and photographs used in the book. Instructors may use these jpegs to create their own PowerPoint® presentations.

•

DayOne: Day One—Prof InClass is a PowerPoint presentation that you can customize to orient your students to the class and their text at the beginning of the course.

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 1 Careers in the Automotive Industry CHAPTER OVERVIEW This chapter examines the automotive industry today and points out the changes that are occurring. Professional service provided by a properly trained technician is critical because of the technology used in today’s vehicles. A detailed description is given of what it takes to be a professional technician. Included are descriptions of career opportunities, job classifications, and the various automotive education programs that are available in Canada. Automotive Service Technician Interprovincial Standards and ASE certification requirements are also provided.

LEARNING OUTCOMES • • • • • • •

Describe the reasons why today’s automotive industry is considered a global industry. Explain how computer technology has changed the way vehicles are built and serviced. Explain why the need for qualified automotive technicians is increasing. Describe the major types of businesses that employ automotive technicians. List some of the many job opportunities available to people with a background in automotive technology. Describe the different ways a student can gain work experience while attending classes. Describe the requirements for Red Seal certification of automotive technicians.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Servicing Today’s Vehicles A. The Importance of Automotive Technicians B. The Need for Quality Service C. The Need for Ongoing Service 1. Warranties 2. Increased Vehicle Age Hint: Discuss the need for repairs as cars become older and what opportunities this need presents to a qualified technician. D. Career Opportunities 1. Dealerships 2. Independent Service Shops 3. Franchise Repair Shop 4. Store-Associated Shops 5. Fleet Service and Maintenance Hint: Discuss career opportunities in all areas of automotive service. II. Job Classifications A. Service Technician

1-1

Automotive Technology: A Systems Approach, 3Ce B. Shop Foreman C. Service Adviser D. Service Manager E. Service Director F. Parts Counterperson G. Parts Manager Hint: Discuss the various automotive shop positions and how they each relate to the technicians. III. Related Career Opportunities A. Parts Distribution B. Marketing and Sales C. Other Opportunities IV. Training for a Career in Automotive Service A. Student Work Experience 1. Job Shadowing Program 2. Mentoring Program 3. Cooperative Education 4. Part-Time Employment B. Canada’s Automotive Apprenticeship Program 1. Red Seal Program C. The Need for Continuous Learning V. ASE Certification Hint: Introduce the various programs in your area that are available to students.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • • •

Without experience, students will struggle with understanding how an automotive shop functions. Possibly have a shop owner visit the class or arrange to take the students to observe a shop during operating hours. To help students understand a shop’s different job classifications, place various students as the shop foreman or service writer and have them arrange the “workload” for the day’s shop activities. Have the students refer to the job classification section of the chapter as a reference for these assignments. Refer to page 9 of Chapter 1 for reference.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Go to a new car dealership and get a sales brochure on a new car or truck of your choice. Then read it carefully from beginning to end. Make a list of all of the systems on that vehicle that are controlled by electronics. If you are unsure, put the name of the system down on the list and talk to your instructor about it.

1-2

Automotive Technology: A Systems Approach, 3Ce 2. Look through the help-wanted section of the local newspaper. Cut out all of the employment opportunities available to someone trained in automotive technology. Do not limit your search to one or two job classifications; look through many. 3. Based on the ads found in the previous activity, put together a summary of the jobs that are currently available. Include in the summary the desired qualifications and the type of facilities in need of qualified technicians.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Electronics are widely used because they allow for rapid response to changes in operating conditions; they are inexpensive, lightweight, and very reliable. 2. To become a successful automotive technician you must be able to master and keep up with the latest technologies, and you must possess the skills to work well with people. 3. There are a variety of types of businesses that employ automotive technicians. a. Dealerships provide repair and maintenance on vehicles while they are under warranty and beyond. They offer the technician good technical support, special diagnostic equipment, an opportunity to specialize, and ongoing training. A disadvantage could be becoming limited to one or two particular model lines. b. Independent repair shops service all types of vehicles, sometimes specializing in certain areas of repair, or in either import or domestic vehicles. This type of shop may present constant service and diagnostic challenges to the technician, providing an opportunity to gain a well-rounded technical background. Disadvantages may include having less sophisticated diagnostic equipment to work with and less dealership sponsored training. c. Store-associated shops provide certain specialized services such as brakes, exhaust systems, and wheel and tire repair. An advantage to the technician is the ability to specialize in one area and product. A disadvantage is not becoming as well rounded in other areas of automotive service. d. Specialty service shops provide repairs in specialized repair areas such as engine rebuilding, transmission/transaxle overhauling, brake, exhaust, emissions, or electrical systems. Technicians can become very skilled in the specialized area, but they can also limit themselves. e. Fleet service and maintenance shops provide service and maintenance for a fleet of company-owned vehicles. Their technicians can become very familiar with a wide range of vehicles over an extended period of time. 4. There are many ways that you can gain work experience while you are a student. They include: a. job shadowing, b. mentoring, c. cooperative education, d. apprenticeship, e. parttime employment. 5. d. During the on-the-job portion of an apprenticeship, the apprentice must complete a prescribed set of complete vehicle repair tasks. 6. b. While a vehicle is still under warranty, repairs are usually performed in dealership service departments. 7. c. Specialty shops perform work on one or more specific automotive systems. 8. d. The service adviser prepares cost estimates. 9. a. The vehicle’s electronics have produced the greatest changes in today’s automobiles. Electronics have affected the operation of almost every automotive system including improvements to engine performance, emission control, braking systems, and passenger comfort to name a few. 10. d. A successful technician must possess each of the skills listed.

1-3

Automotive Technology: A Systems Approach, 3Ce 11. d. Tire rotation would be performed under scheduled preventative maintenance. Water pump replacement and transmission overhaul would only be performed when a failure or signs of impending water pump or transmission failure occurs. Engine oil replacement is a regular maintenance item that does not necessarily have to be only performed during a preventative maintenance service. 12. b. The automobile manufacturer determines the new car warranty conditions for the automobile’s engine and drive train systems. 13. d. The government mandates the length of time and amount of kilometres that emission control devices are to be covered under warranty. 14. d. To become a certified automotive technician in most Canadian provinces you must complete an automotive service technician apprenticeship. 15. b. Although each province may set a minimum grade to obtain a provincial certificate, a 70% grade must be achieved to obtain a Red Seal endorsement. 16. c. A prorated warranty decreases over time. 17. a. A prorated warranty is commonly provided on tires and batteries. 18. c. Wholesalers are commonly known in the automotive industry as jobbers. Jobbers sell aftermarket parts and supplies to automotive service shops and the general public. 19. a. The advantage of a Red Seal endorsement is that it allows an automotive service technician to work in most Canadian provinces without further testing because it is recognized as a high standard of achievement. 20. d. ASE testing in Canada is voluntary testing in various automotive technology areas.

1-4

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 2 Workplace Skills CHAPTER OVERVIEW This chapter describes the workplace skills needed to successfully obtain a job and how to keep it. Among the topics discussed are the preparation of a resumé and cover letter, and how to prepare for a job interview. The basis for good workplace skills is respect. You must not only have respect for yourself, but also for your employer, your fellow employees, and your customers.

LEARNING OUTCOMES

• • • • • • • • • • •

Develop a personal employment plan. Seek and apply for employment. Prepare a resumé and cover letter. Prepare for an employment interview. Accept employment. Understand how automotive technicians are compensated. Understand the proper relationship between an employer and an employee. Explain the key elements of on-the-job communications. Be able to use critical thinking and problem-solving skills. Explain how you should look and act to be regarded as a professional. Explain how fellow workers and customers should be treated.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Seeking and Applying for Employment A. Employment plan B. Identifying Job Possibilities C. Driving Record D. Preparing Your Resumé E. References F. Preparing Your Cover Letter G. Contacting Potential Employers H. Applications I. The Interview

1-5

Automotive Technology: A Systems Approach, 3Ce J. After the Interview Hint: Show examples of good and poorly completed resumés, cover letters, and applications. Have the students apply for a mock job opening. Block out the names and have the class look at the applications, cover letters, and resumés and vote on which applicant would most likely get hired. II. Accepting Employment A. Compensation 1. Hourly Wage 2. Commission 3. Flat Rate 4. Team System 5. Benefits 6. Total Earnings III. Working as an Automotive Technician A. Employer–Employee Relationships 1. Instruction and Supervision 2. Clean, Safe Place to Work 3. Wages 4. Benefits 5. Opportunity and Fair Treatment 6. Regular Attendance 7. Following Directions 8. Team Membership 9. Responsibility 10. Productivity 11. Loyalty Hint: Invite a shop foreman or service manager to speak to the students about what characteristics are most valued in employees. IV. Communications A. Nonverbal Communication Hint: Have a student demonstrate various nonverbal communications and let the class decide what is being communicated. V. Solving Problems and Critical Thinking A. Diagnosis Hint: Provide several puzzles or riddles to allow the students to test their critical thinking skills. VI. Professionalism A. Coping with Change VII. Interpersonal Relationships A. Customer Relations Hint: Invite a receptionist or a similar professional to talk to the students about telephone etiquette and customer relations.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

Young people entering the workforce will not necessarily have the skills to communicate effectively or with confidence. Practise putting students into the roles of customer and technician discussing

1-6

Automotive Technology: A Systems Approach, 3Ce

• •

problems with their vehicles. This will give the instructor the opportunity to discuss communication skills. Have the students write an ad seeking a technician for employment. Use this as a tool to evaluate what their idea is of a good employee. Refer to page 19 of Chapter 2 for reference. Have the students research the flat rate time for all jobs they perform in the shop, this will help them to understand time management. Page 26 of Chapter 2 refers to flat rate.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Read your local newspaper and clip four employment opportunities in the automotive field. 2. Prepare a resumé including the following elements: contact information, career objectives, skills and/or accomplishments, work experience, education, and a statement about provision of references. 3. Choose one of the employment opportunities from Shop Activity 2–1 and write a cover letter for it. 4. Prepare a repair estimate for the replacement of a clutch, and be sure to include the appropriate taxes for your area of the country.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Your employment plan should include your specific job goals and a plan to reach them. You should list your interests, skills, and attitudes that match the job you are seeking. Include both your short-term and long-term goals along with a prioritized list of potential employers. 2. Flat rate means that each technician is paid according to the amount of work produced. Each job has a flat-rate time, and the technician is paid for that amount of time regardless of how long it takes to complete the task. The flat-rate system rewards the most productive technicians, while providing for more accurate repair estimates. 3. Your cover letter should include three paragraphs. The first should describe your interest in working for this employer and the position you are seeking. The second paragraph is used to sell yourself, and the third is used as a closing by thanking the employer and requesting an interview. 4. b A good technician will always gather as much information as they can about the problem before using valuable shop time performing tests or replacing components that may or may not relates to the problem. 5. a. A good resumé will be neat, uncluttered, and easy to read. It should not list all of the jobs you have ever had and it should be a maximum of 2 pages in length. All important information should be listed near the beginning so it is noticed immediately. 6. b. A past or present teacher would make a good reference on a resumé. Friends and family should not be used as references. 7. b. The best way to quit a job is to write a letter of resignation and present it personally to the employer. 8. d. The application should be filled out completely. Answer every question. Write “N/A” if a question does not apply to you. 9. a. Show up at an interview looking neat and professional by wearing clothes that you would wear on the job or even more formal.

1-7

Automotive Technology: A Systems Approach, 3Ce 10. d. Leaning forward and nodding shows good nonverbal communication during an interview. Leaning forward shows that you are actively engaged in the conversation, while nodding shows understanding. 11. b. A letter of thanks should be sent to the employer within three days after the interview. 12. d. You should not only look at people while they are speaking to you, but also listen carefully without interruption before responding. 13. c. Supervising other people is a soft skill. Soft skills are personal skills that are part of your personality and are used while relating to other people. 14. a. The enjoyment of solving puzzles or problems is an example of a technical skill rather than a personal skill. 15. d. The technician should expect to be paid $80 for the repair because the flat-rate system pays the technician for the job completed, not the actual time the technician required. 16. b. In person is the best method of submitting a resumé. This can provide a physical presence along with the resumé and possibly a meeting with the employer. 17. c. Employment and Social Development Canada issues social insurance number (SIN) cards. 18. a. Straight time is the recommended pay plan for new and inexperienced technicians/apprentices because it does not place undue stress on them to complete repairs at the same rate as experienced technicians.

1-8

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 3 Working Safely in the Shop CHAPTER OVERVIEW This chapter discusses shop safety in detail. The topics range from clothing and eye protection to handling tools, vehicle handling in the shop, and handling hazardous waste. The instructor might want to refer to this chapter for review when discussing safety issues in later chapters.

LEARNING OUTCOMES

• •

Understand the importance of safety and accident prevention in an automotive shop.

Explain the basic principles of personal safety, including protective eye wear, clothing, gloves, shoes, and hearing protection.

• • •

Explain the procedures and precautions for safely using tools and equipment. Explain the precautions that need to be followed to safely raise a vehicle on a lift.

Explain what should be done to maintain a safe working area in a shop, including running the engines of vehicles in the shop and venting the exhaust gases.

•

Describe the purpose of the laws concerning hazardous wastes and materials, including the WHMIS right-to-know legislation.

•

Describe your rights, as an employee and/or student, to have a safe place to work.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Personal Safety A. Personal Safety Precautions 1. Eye Protection 2. Eye First Aid 3. Clothing 4. Hair and Jewellery 5. Shoes 6. Gloves 7. Disease Prevention 8. Ear Protection 9. Respiratory Protection 10. Lifting and Carrying B. Professional Behaviour Hint: Invite the students to tell about persons they are acquainted with who have had work-related injuries. ©2016 Nelson Education Ltd.

1-9

Automotive Technology: A Systems Approach, 3Ce II. Tool and Equipment Safety A. Hand Tool Safety B. Power Tool Safety C. Compressed Air Equipment Safety D. Lift Safety E. Jack and Jack Stand Safety F. Chain Hoist and Crane Safety G. Cleaning Equipment Safety 1. Chemical Cleaning 2. Thermal Cleaning 3. Abrasive Cleaning H. Vehicle Operation 1. Venting the Engine’s Exhaust I. Electrical Safety 1. Battery Precautions 2. High-Voltage Systems J. Rotating Pulleys and Belts Hint: Show the students various items of equipment in the shop and explain the safety concerns related to each. III. Work Area Safety A. Flammable Liquids 1. Gasoline 2. Ethanol 3. Diesel Fuel B. Fire Extinguishers Hint: Show where the fire extinguishers are located and tell how they should be operated. IV. Manufacturer’s Warnings and Government Regulations A. Chemical Hazards B. Hazardous Wastes C. Physical Hazards D. Ergonomic Hazards E. CEPA (Canadian Environmental Protection Act) V. WHMIS Right-To-Know Legislation VI. Hazardous Materials Hint: Show the MSDS sheets and the substances they apply to in your work area. A. Guidelines for Handling Shop Wastes 1. Oil 2. Oil Filters 3. Batteries 4. Metal Residue from Machining 5. Refrigerants 6. Solvents 7. Containers 8. Other Solids 9. Liquid Recycling 10. Shop Towels/Rags 11. Hiring a Hauler 12. Waste Storage Hint: Show the students where in their work areas these items are to be disposed of. B. Asbestos

1-10

Automotive Technology: A Systems Approach, 3Ce

ADDITIONAL TEACHING HINTS

•

Show the students the equipment they will be working with and describe the safety concerns for each item. Point out areas where personal equipment such as protective eyewear and hearing protection is required.

•

Show the students the MSDS manual and show a sample of each substance they will be using. Describe the safe handling and disposal procedures for each.

• •

Show where the emergency phone numbers are located and describe accident reporting procedures.

Walk through the lab with each student listing safety concerns they find such as tripping hazards, spills, and so on. Compare their lists and lead a discussion of each person’s responsibility to maintain a safe work area.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

One of the most common misconceptions is the lack of realization of the effects of chronic exposure to many chemicals and solutions used in the automotive trade. Have the students research cases of technicians being affected by chronic exposure. If possible bring people into the class who have suffered from chronic exposure or other types of injuries. Allow the students to take turns being safety officer for the class while in the shop.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Make a simple line drawing of the shop. Then walk around the shop and identify all safety equipment. Mark the location of the equipment on your drawing. 2. Walk around the shop and list everything that is a safety hazard 3. Identify all storage areas for hazardous materials and wastes. Make sure they are properly labelled. 4. Locate all of the fire extinguishers in the shop. Make a note of what type of fires each will extinguish. 5. Locate the MSDSs or WHMIS manual in the shop.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Used oil filters should be drained for at least 24 hours, then crushed and recycled. 2. Up-to-date phone numbers for doctors, hospitals, and the fire and police departments should be clearly posted next to the phone. 3. Some shops have posted areas where safety glasses are required; for example, there may be a red line painted on the floor with a sign warning that safety glasses are required beyond the red line. Any time a person is working around risks such as vapours, dust, metal shavings, or liquids that may cause eye injuries, safety glasses should be worn. 4. A class B fire extinguisher should be used to smother the fire. Apply a blanketing, flameinterrupting covering over the entire flaming liquid surface.

1-11

Automotive Technology: A Systems Approach, 3Ce 5. When fighting a fire, stand 2 to 3 metres (7 to 10 ft.) away from the fire and aim the fire extinguisher nozzle at the base of the fire. Use a side to side sweeping motion over the entire width of the fire until the fire is extinguished. Stay low to avoid inhaling the smoke and get out if it gets too hot or smoky. 6. b. A mask equipped with HEPA (high efficient particulate arresting) filters should be used when working with brake shoes or clutch discs. 7. c. Safety glasses should be worn any time that you are working in the shop. 8. d. A multipurpose dry chemical fire extinguisher can be used on electrical fires. Carbon dioxide, halogenated agent, standard dry chemical, and Purple K dry chemical can also be used. 9. a. Brake shoes do not require approved waste disposal collection. 10. d. WHMIS (Workplace Hazardous Material Information System) relates to the right-to-know legislation. 11. c. Further cleaning to remove residue is necessary following thermal cleaning. 12. b. WHMIS right-to-know legislation relates to hazards associated with chemicals used in the workplace 13. b. CO (Carbon monoxide) is a poisonous gas that requires proper ventilation. 14. d. When a material reacts violently with water, or other materials, it is said to have high reactivity. 15. b. When extinguishing a fire, you should remain 2 to 3 metres (7 to 10 ft.) away. 16. c. Keep your back as straight as possible when lifting an object. 17. d. The recommended way to store gasoline is in an approved safety container in a designated storage cabinet. 18. a. Compressed air can be used to blow dirt from bolt holes. Compressed air should not be used for cleaning surfaces that can be safely cleaned by other safer methods. 19. c. Nitrile gloves should be worn when washing parts because of their resistance to gas, oil, and solvents. 20. d. Oil filters should be allowed to drain for 24 hours before being crushed and recycled.

1-12

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 4 Automotive Systems CHAPTER OVERVIEW This chapter discusses significant automotive features and design revolution. The latest, most progressive changes are emphasized. The basic automobile systems covered in later chapters are introduced.

LEARNING OUTCOMES

•

Explain the major events that have influenced the development of the automobile in the recent past.

• • •

Explain the difference between unitized and body-over-frame vehicles. Describe the manufacturing process used in a modern automated automobile assembly plant.

List the basic systems that make up an automobile and name their major components and functions.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Historical Background II. Modern Power Plants III. Design Evolution A. Unitized Construction B. Body-over-Frame Construction IV. Body Designs A. Sedan B. Convertible C. Liftback or Hatchback D. Station Wagon E. Pickups F. Vans G. Sport Utility Vehicles (SUVs) H. Crossover Vehicles I. Hybrid Vehicles J. Electric Vehicles V. Technological Advances VI. The Basic Engine A. Cylinder Block B. Cylinder Head

1-13

Automotive Technology: A Systems Approach, 3Ce C. Piston D. Connecting Rods and Crankshaft E. Valve Train F. Manifolds VII. Engine Systems A. Lubrication System B. Cooling System C. Fuel and Air System D. Emission Control System 1. Positive Crankcase Ventilation (PCV) System 2. Evaporative Emission Control System 3. Exhaust Gas Recirculation (EGR) System 4. Catalytic Converter 5. Air Injection System E. Diesel Emission Controls F. Exhaust System VIII. Electrical and Electronic Systems A. Ignition System B. Starting and Charging Systems C. Electronic Engine Controls D. On-Board Diagnostics IX. Heating and Air-Conditioning Systems A. Heating Systems B. Air-Conditioning Systems 1. Compressor 2. Condenser 3. Receiver/Dryer 4. Accumulator 5. Thermostatic Expansion Valve/Orifice Tube 6. Evaporator 7. Refrigerant Lines X. Drivetrain A. Transmission and Transaxles B. Clutch C. Manual Transmission D. Automatic Transmission E. Dual-Clutch (Shaft) Transmissions F. Continuously Variable Transmissions (CVTs) G. Driveline H. Rear Axle/Final Drive I. Driving Axles J. Transaxle K. Four-Wheel-Drive System XI. Running Gear A. Suspension System B. Steering System C. Brakes D. Wheels and Tires XII. Hybrid Vehicles A. Electric Vehicles XIII. Alternative Fuels ©2016 Nelson Education Ltd.

1-14

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Constant technological changes can cause a great deal of confusion for new technicians and students. Bring three or four vehicles into the shop from the last three or four decades and demonstrate the advancements in the various systems. Students will stumble with understanding the multitude of systems contained within modern vehicles, and how they all tie together. Use this chapter and have the students draw block diagrams of the various systems and have them tie them together

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Pick 10 vehicles from those available in the lab for you to work on. Write out a complete description of each one. In this description include the type and/or size (where applicable) for each of the following: year, make, model, body design, engine, drivetrain, steering, suspension, brake system, and any other feature or accessory that may be evident. 2. Define each of the basic engine components and systems listed. Refer to your textbook. When you have completed the definitions, go into the shop and identify the components and systems on a vehicle. 3. Define each of the heating and air-conditioning components listed. Refer to your textbook. When you have completed the definitions, go to the shop and identify the components on a vehicle. 4. Define each of the drivetrain components listed. Refer to your textbook. When you have completed the definitions, go into the shop and identify the components on a vehicle. 5. Define each of the systems and components of the running gear. Refer to your textbook. When you have completed the definitions, go into the shop and identify the systems and components on a vehicle. 6. If a hybrid vehicle is available, safely identify the components of the hybrid system. Use caution around any of the high-voltage components. They are typically identified by orange cabling or conduit. NOTE: Always assume a hybrid vehicle is capable of moving as the electric motors can operate silently whenever the ignition is on.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The Company Average Fuel Consumption (CAFC) is a voluntary Canadian program that is similar to the mandatory Corporate Average Fuel Economy (CAFE) standards in the United States that require a certain fuel economy average for all vehicles produced by a manufacturer. 2. The benefits of switching from rear wheel drive to front wheel drive include improved traction, increased interior space, shorter hood lines, and a very compact driveline. 3. Internal combustion means that the fuel is burned inside the engine to produce energy. 4. In addition to the battery, a charging system should include a generator, voltage regulator, charge indicator light or gauge, and the necessary wiring.

1-15

Automotive Technology: A Systems Approach, 3Ce 5. The difference between a parallel and series hybrid design is mainly that a parallel hybrid can be propelled by either the internal combustion engine or the electric motor and a true series hybrid can only be propelled by the electric motor. 6. d. EFE (Early Fuel Evaporation) is a type of emission control that preheats the fuel mixture prior to its entry to the intake manifold. This improves fuel vaporization when the engine is cold. 7. c. Automatic transmissions use torque converters instead of clutches. 8. b. The four-stroke cycle gasoline engine is classified as an internal combustion engine because the fuel ignites and burns inside the engine or internally. 9. b. The positive crankcase ventilation (PCV) system routes fuel and engine oil vapours to the intake manifold where they can be drawn into the engine to be burnt along with the air/fuel mixture. 10. b. The crossover vehicle is based on a station wagon and an SUV. 11. a. The order of strokes in a four-stroke cycle gasoline engine is intake, compression, power, and exhaust. 12. d. The valve train opens and closes the intake and exhaust ports of each cylinder. 13. b. The pressure cap raises the boiling point of the engine cooling systems coolant by allowing the coolant to operate under a controlled pressure above atmospheric. 14. a. A pickup truck would most likely utilize the body-over-frame construction. This style of construction is more suited for the load carrying capabilities of pickup trucks. 15. b. The exhaust gas recirculation (EGR) system introduces exhaust gasses into the intake manifold in order to reduce NOx emissions. The entry of exhaust gases into the combustion chamber will dilute the air/fuel mixture reducing the combustion temperature which will reduce the formation of NOx emissions. 16. c. The battery is part of both the charging and starting systems. 17. c. A front-wheel drive car commonly uses a transaxle. The transaxle contains both the transmission and final drive components. 18. a. The differential is part of the drive train. 19. c. The orifice tube works with the compressor to separate the high and low sides. 20. a. The reductant used in diesel exhaust systems separates the oxygen from NOx and combines with hydrogen to form water.

1-16

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 5 Hand Tools and Shop Equipment CHAPTER OVERVIEW This chapter presents some of the more commonly used hand and power tools with which every technician must be familiar. Because units of measurement play such an important part in tool selection and in diagnosing automotive problems, this chapter begins with a presentation of measuring systems. Prior to the discussion on tools, there is a discussion on another topic that relates very much to measuring systems and fasteners.

LEARNING OUTCOMES

•

List the basic units of measurement for length, volume, and mass in the two measuring systems.

• • • • • •

Describe the different types of fasteners used in the automotive industry. List the various mechanical measuring tools used in the automotive shop. Describe the proper procedure for measuring with a micrometer. List some of the common hand tools used in auto repair. List the common types of shop equipment, and state their purpose.

Describe the use of common pneumatic, electrical, and hydraulic power tools found in the automotive service department.

•

Describe the different sources for service information that are available to technicians.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Measuring Systems II. Fasteners 1. Locknuts 2. Machine Screws A. Bolt Identification B. Tightening Bolts C. Washers D. Thread Lubricants and Sealants E. Thread Pitch Gauge F. Taps and Dies G. Threaded Inserts 1. Spark Plug Thread Repair Hint: Show examples of metric and SAE bolt and nut classifications and how to

1-17

Automotive Technology: A Systems Approach, 3Ce correctly identify them. Compare grade strengths and discuss the differences in torque and holding power. Show an example of a bolt with stretched threads. III. Measuring Tools A. Machinist’s Rule B. Vernier Caliper C. Dial Caliper D. Micrometers 1. Reading a Metric Outside Micrometer 2. Using an Outside Micrometer 3. Reading an Inside Micrometer 4. Reading a Depth Micrometer E. Telescoping Gauge F. Small Hole Gauge G. Feeler Gauge H. Straightedge I. Dial Indicator IV. Hand Tools A. Wrenches 1. Open-End Wrench 2. Box-End Wrench 3. Combination Wrench 4. Flare Nut (Line) Wrenches 5. Allen Wrench 6. Adjustable-End Wrench B. Sockets and Ratchets 1. Special Sockets 2. Crowfoot Wrench Adapters 3. Extensions 4. Socket Adapters C. Torque Wrenches D. Screwdrivers E. Impact Screwdriver F. Pliers G. Hammers H. Chisels and Punches I. Removers J. Hacksaws K. Files L. Gear and Bearing Pullers M. Bearing, Bushing and Seal Drivers N. Trouble Light O. Creeper V. Shop Equipment A. Bench Vises B. Bench Grinder C. Presses D. Grease Guns E. Oxyacetylene Torches 1. Welding and Heating Torch 2. Cutting Torch 3. Precautions

1-18

Automotive Technology: A Systems Approach, 3Ce 4. MINI-DUCTOR® VI. Power Tools A. Impact Wrench B. Air Ratchet C. Air Drill D. Blowgun VII. Jacks and Lifts A. Floor Jack B. Lift C. Portable Crane D. Engine Stands/Benches VIII. Service Information A. Auto Manufacturers’ Service Information B. General and Specialty Repair Manuals C. Finding Information D. Aftermarket Suppliers’ Guides and Catalogues E. Lubrication Guides F. Owner’s Manuals G. Hotline Services H. iATN

ADDITIONAL TEACHING HINTS

• • • •

Discuss the power tools provided in the shop and the safety rules for each tool. Demonstrate as many tools in Chapter 5 as practical. Have students sort and identify bolts and other fasteners by grade, thread pitch, and type.

Demonstrate and review shop manual usage. If computer-based service manuals are available, show how to access information.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

•

Canadian students will have a more difficult time working in imperial measurement. Provide a number of examples where imperial and metric sizes are very similar to help with visual reference. Having a proper understanding of the correct tool to use for a particular job can be difficult for beginning technicians. Create a few scenarios where it would be possible to pick a variety of tools for a repair. Discuss with students why certain tools should or should not be used to perform the repair. Use information starting on page 87 of Chapter 5 for reference.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using the formulas given in the textbook, convert the following into inch measurements: 72 mm, 113 cm, and 0.072 mm. Now convert the following inch measurements into metric measurements: ½ inch, 0.002 inch, and 3 inches.

1-19

Automotive Technology: A Systems Approach, 3Ce

2. Have your instructor give you an assortment of fasteners. Identify each using the information given in the textbook. Make sure you describe the purpose and size of each. 3. Using a micrometer, list the micrometer reading of the 10 drill shanks supplied by your instructor. The masking tape on the drill shank is covering up the actual drill size; please do not remove the tape. The number on the masking tape is used as a reference in the recording of the drill shank sizes. 4. With the guidance of your instructor, raise the front of a vehicle off the ground and set it on safety (jack) stands. Secure a dial indicator with the proper holding mechanisms so that the indicator’s plunger barely contacts the outside rim of one of the front wheels. With the plunger contacting the rim, set the dial to zero. Slowly rotate the wheel and watch the indicator. Any indicator needle movement indicates that there is some wheel distortion. 5. Take complete inventory of the tools in your toolbox or one assigned to you. Cross-reference the supplied tool list to the tools on hand. If a tool list is not available to you, list the type of tool and the size of each tool in the set.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A micrometer should be checked weekly and also right after you drop it. 2. Use a dial indicator for such things as measuring valve lift, crankshaft endplay, flywheel or brake rotor runout, gear backlash, or crankshaft journal concentricity. 3. The size of a wrench is determined by the distance between its jaws measured in millimetres or fractions of an inch. This size will be slightly larger than the indicated size so that it will fit around a nut or bolt. 4. True. Service manual information is usually also made available by certain manufacturers on CDs, DVDs, or via the Internet. 5. In the imperial system, the tensile strength of a bolt is identified by the Society of Automotive Engineers (SAE) and they use a number of radial lines on the bolt’s head. More lines mean higher tensile strength. A property class number on the bolt head identifies the grade of metric bolts. This numerical identification is from the International Organization for Standardization (ISO) and is comprised of two numbers. The first number represents the tensile strength of the bolt. The higher the number means the greater the tensile strength. The second number represents the yield strength of the bolt. 6. b. A box-end wrench is not likely to slip off a bolt or a nut. 7. c. The thimble on a metric micrometer has 50 graduations. 8. b. Each graduation on the thimble of a metric micrometer equals 1/100 or 0.01 millimetre. 9. c. A Pozidriv® screwdriver is similar to a Phillips, but flatter and blunter. 10. b. Needle nose pliers are best for grasping small parts. 11. b. A brass drift punch should be used to drive roll pins from aluminum components. Brass will produce much less damage to the aluminum component and drifts have straight shafts and are available in different sizes to pass through the roll pin bore. 12. d. An extractor is used to remove broken bolts. 13. a. A ball gauge would be used to measure a valve guide bore along with other small bores. 14. c. A micrometer should be used when the measurement must be within one-hundredth of a millimetre. 15. d. Fillet damage would cause a bolt head to pop off. The fillet provides support between the bolt head and shank.

1-20

Automotive Technology: A Systems Approach, 3Ce 16. a. A hand tap can be used to thread a nut. A hand tap produces internal threads. 17. c. A vernier caliper can be used to measure inside, outside and depth measurements. 18. a. Torx® fasteners are generally used to secure headlamp assemblies, mirrors, and luggage racks due to their ability to handle more turning force with a lesser chance of slippage. 19. b. Before working under a vehicle on a hydraulic lift, always ensure that all locking devices are fully engaged to prevent the vehicle from dropping due to a hydraulic failure. 20. c. Manufacturers publish technical service bulletins when new service procedures or component updates are needed.

1-21

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 6 Diagnostic Equipment and Special Tools CHAPTER OVERVIEW This chapter describes the diagnostic equipment and special tools used by technicians to diagnose and service various automotive systems. Diagnostic equipment is used to test the performance of a system, and special tools designed for a particular purpose are used to make the necessary repairs.

LEARNING OUTCOMES

•

Describe the various diagnostic and service tools used to check and repair an engine and its related systems.

•

Describe the various diagnostic and service tools used to check and repair electrical and electronic systems.

•

Describe the various diagnostic and service tools used to check and repair a vehicle’s drivetrain.

•

Describe the various diagnostic and service tools used to check and repair a vehicle’s running gear for wear and damage.

•

Describe the various diagnostic and service tools used to check and repair a vehicle’s heating and air-conditioning system.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Engine Repair Tools A. Compression Testers B. Cylinder Leakage Tester C. Oil Pressure Gauge D. Stethoscope 1. Electronic Stethescope E. Engine Removal and Installation Equipment F. Ridge Reamer G. Ring Compressor H. Ring Expander I. Ring Groove Cleaner J. Dial Bore Indicator K. Cylinder Deglazer L. Cylinder Hone M. Cam Bearing Driver Set N. V-Blocks ©2016 Nelson Education Ltd.

1-22

Automotive Technology: A Systems Approach, 3Ce O. Valve and Valve Seat Resurfacing Equipment P. Valve Guide Repair Tools Q. Valve Spring Compressor R. Valve Spring Tester S. Torque Angle Gauge T. Oil Priming Tool U. Cooling System Pressure Tester V. Coolant Hydrometer 1. Refractometer Testers 2. Measuring pH W. Coolant Recovery and Recycle System II. Electrical/Electronic System Tools A. Computer Memory Saver B. Circuit Tester C. Multimeter D. Voltmeter E. Ohmmeter F. Ammeter G. Volt/Ampere Tester H. Battery Capacitance Tester I. Lab Scopes J. Graphing Multimeter K. Battery Hydrometer L. Wire and Terminal Repair Tools M. Headlight Aimers III. Engine Performance Tools A. Scan Tools B. Engine Analyzers C. Fuel Pressure Gauge D. Pressure Transducer E. Injector Balance Tester F. Injector Circuit Test Light G. Fuel Injector Cleaners H. Fuel Line Tools I. Pinch-Off Pliers J. Vacuum Gauge K. Vacuum Pump L. Vacuum Leak Detector M. Tachometer N. Spark Tester O. Logic Probes P. Sensor Tools Q. Static Strap R. Pyrometer S. Spark Plug Sockets T. Exhaust Analyzers U. Chassis Dynamometer V. Hybrid Tools 1. Gloves 2. Test Equipment

1-23

Automotive Technology: A Systems Approach, 3Ce IV. Transmission and Driveline Tools A. Transaxle Removal and Installation Equipment B. Transmission/Transaxle Holding Fixtures C. Transmission Jack D. Axle Pullers E. Special Tool Sets F. Clutch Alignment Tool G. Clutch Pilot Bearing/Bushing Puller/Installer H. Universal Joint Tools I. Driveshaft Angle Gauge J. Hydraulic Pressure Gauge Set V. Suspension and Steering Tools A. Tire Tread Depth Gauge B. Tire Pressure Monitoring Sensor (TPMS) Tester C. Power-Steering Pressure Gauge D. Control Arm Bushing Tools E. Tie-Rod End and Ball Joint Puller F. Front Bearing Hub Tool G. Pitman Arm Puller H. Tie-Rod Sleeve-Adjusting Tool I. Steering Column Special Tool Set J. Shock Absorber Tools K. Spring/Strut Compressor Tool L. Power Steering Pump Pulley Special Tool Set M. Brake Pedal Depressor N. Wheel Alignment Equipment—Four Wheel O. Tire Changer P. Wheel Balancer—Electronic Type Q. Wheel Weight Pliers R. Road Force Balaancer VI. Brake System Tools A. Cleaning Equipment and Containment Systems B. Hold-Down Spring and Return Spring Tools C. Boot Drivers, Rings, and Pliers D. Caliper Piston Removal Tools E. Drum Brake Adjusting Tools F. Brake Cylinder Hones G. Tubing Tools H. Brake Disc Micrometer I. Drum Micrometer J. Brake Shoe Adjusting Gauge (Calipers) K. Brake Lathes L. Bleeder Screw Wrenches M. Pressure Bleeders VII. Heating and Air-Conditioning Tools A. Manifold Gauge Set B. Electronic Leak Detector C. Fluorescent Leak Tracer D. Refrigerant Identifier E. Refrigerant Charging Station F. Thermometer

1-24

Automotive Technology: A Systems Approach, 3Ce G. Compressor Tools H. Hose and Fitting Tools

ADDITIONAL TEACHING HINTS

• • • • •

Demonstrate DMM voltage, amps, and ohm tests on various car circuits. Demonstrate how to observe ignition timing with a timing light and how timing affects engine operation. Demonstrate how to connect and adjust a labscope. Demonstrate on a two- or four-gas exhaust analyzer how the gases change if a cylinder is disabled. Discuss details of how to hook up an engine analyzer to a vehicle.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Identifying specialty tools will be a stumbling block for most beginning automotive students. Create a list of 10–15 of these tools and have the students find them in the tool room. Use this chapter’s diagrams to assist in their identification. Set up four or five vehicles in the shop with specialty tools attached to them and operating. Have the students identify the tools and what test they are performing. Visual conception helps with remembering a tools’ use. This aid will take a little time from the instructor but should help with the understanding of the use of some of the specialty tools.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Use a scan tool to retrieve the diagnostic fault codes from a vehicle.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. There are two types of test lights. The first is sometimes called a circuit tester and is used to check for the presence of voltage in a circuit. A ground clip is attached to a suitable ground, and the tester lights when the probe is touched to a portion of the circuit having sufficient voltage present. The second is sometimes referred to as a self-powered test light or continuity tester. It has an internal battery and is used to check unpowered portions of a circuit for continuity. When the ground clip is attached to the negative side of the circuit and the probe is attached to the positive side, the tester will light when there is continuity in the circuit. 2. False. Knurling is used to decrease the inside diameter of the guide. 3. The two types of compression gauges are push-in and screw-in. 4. A vacuum gauge is used to test engine manifold vacuum. 5. True. A lab scope is a visual voltmeter that shows voltage over a period of time. 6. b. A brake shoe adjusting gauge provides a quick, rough adjustment of the brake shoes. Further adjustment is necessary after the brake drum is installed.

1-25

Automotive Technology: A Systems Approach, 3Ce 7. c. Due to the high current draw of a 12-volt test light, they should not be used to test engine control module circuits or any computer controlled circuits. 8. a. An ohmmeter is used to measure the resistance to current flow in a circuit. 9. b. A properly operating engine should produce a vacuum gauge reading of 400 mm Hg (15.7 in. Hg). 10. c. An upward movement of the trace indicates an increase in voltage. 11. a. Performing wheel runout compensation is the first step in performing a four-wheel alignment once the wheel units (heads) are installed. This adjustment ensures that the wheel units are aligned with the axle or spindle and not wheel deformities. 12. b. A manifold gauge set is used for charging and evacuating and for diagnosing trouble in an A/C system. 13. d. When removing a steering wheel, deploying the air bag is a major concern. Always follow the manufacturer’s recommended service procedures. 14. c. A cylinder leakage tester is used to determine where a leak from a cylinder is located. This tester introduces air into the cylinder. 15. d. All of these conditions may be revealed by fuel pressure readings. 16. b. A compression tester reads cylinder pressure during the compression stroke. 17. a. A cylinder should be ridge reamed before piston removal. If the cylinder ridge is not removed it could damage the piston rings and piston ring lands during piston assembly removal. 18. c. Most front-wheel-drive cars have their engines removed by lowering it from the engine compartment. 19. a. The torque angle gauge should be used after the specified torque is obtained. Turning the bolt the additional number of degrees places the specified clamp load on the bolted components. 20. c. Analog multimeters have high impedance (similar to test lights) and should not be used on sensitive electronic circuits.

1-26

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 7 Basic Theories and Math CHAPTER OVERVIEW This chapter introduces many of the principles taught in other courses in order to help the student become more employable and successful as a technician. These principles are covered again in greater detail according to the topic. A thorough understanding of this chapter is recommended to prepare the student for further instruction.

LEARNING OUTCOMES • • • • • • • • • • • • • • •

Describe how all matter exists. Explain what energy is and how energy is converted. Calculate the volume of a cylinder. Explain the forces that influence the design and operation of an automobile. Describe and apply Newton’s laws of motion to an automobile. Define friction and describe how it can be minimized. Describe the various types of simple machines. Differentiate between torque and horsepower. Interpret the difference between a vibration and a sound. Describe Pascal’s law and give examples of how it applies to an automobile. Explain the behaviour of gases. Describe the effects of heat on matter. Describe what is meant by the chemical properties of a substance. Explain the difference between oxidation and reduction. Describe the origin and practical applications of electromagnetism.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Matter A. Atoms and Molecules B. Ions 1. Plasma C. States of Matter 1. Absorption and Adsorption II. Energy A. Kinetic and Potential Energy Hint: Give examples of the various forms of energy. B. Energy Conversion C. Mass and Weight D. Size III. Volume A. Ratios

1-27

Automotive Technology: A Systems Approach, 3Ce B. Proportions IV. Force A. Automotive Forces 1. Balanced and Unbalanced Force 2. Turning Forces B. Forces on Tires and Wheels C. Centrifugal/Centripetal Forces D. Wheel and Tire Balance E. Pressure V. Time VI. Motion A. Rates B. Newton’s Laws of Motion C. Friction 1. Lubrication 2. Rollers D. Air Resistance VII. Work A. Simple Machines 1. Inclined Plane 2. Pulleys 3. Levers 4. Gears 5. Wheels and Axles Hint: Have the class think of examples in which the simple machines listed here may be found in a typical automobile. B. Torque 1. Torque Multiplication C. Power D. Horsepower Hint: Discuss the difference between torque and horsepower. VIII. Waves and Oscillations A. Vibrations B. Sound 1. Speakers C. Noise IX. Light A. Photo Cells X. Liquids A. Laws of Hydraulics B. Mechanical Advantage with Hydraulics Hint: Have the class list all of the systems in an automobile that use hydraulics. XI. Gases A. Behaviour of Gases B. Air Pressure 1. Vacuum XII. Heat A. Heat Transfer B. The Effects of Temperature Change C. Controlling Heat XIII. Chemical Properties

1-28

Automotive Technology: A Systems Approach, 3Ce A. Specific Gravity B. Chemical Reactions C. Catalysts and Inhibitors D. Acids/Bases 1. pH E. Reduction and Oxidation 1. Rust and Corrosion F. Metallurgy 1. Hardness G. Solids under Tension H. Electrochemistry XIV. Electricity and Electromagnetism A. Electricity B. Magnets C. Electromagnetism D. Producing Electrical Energy E. Radio Waves Hint: Have the class list the systems in an automobile that would not function without electricity and magnetism.

ADDITIONAL TEACHING HINTS

•

Using principles learned in the classroom, have the students calculate the displacement of a single cylinder and then the total displacement of several sizes of sample engines.

•

Conduct a tour of the shop and have students list where energy conversions occur in the shop equipment and vehicles found there. Compare lists and lead a discussion of the different forms of energy and their usefulness to us.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Most physics theories will be a struggle for automotive students, the best way to have them understand these theories is to show them practical examples, such as brake pressures/pascal’s law, on page 172 in Chapter 7. To help the students relate the theories to practical applications have them list a number of the laws from this chapter and list the systems that use them.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using the formula in the textbook (under “Volume”), calculate the cubic centimetre and cubic-inch displacement of an engine. Measure engine bore and stroke and calculate engine displacement. Give the metric equivalent of engine displacement in litres. 2. Using the formula in the textbook (under “Gears” or “Torque Multiplication”), calculate the overall gear ratios for each gear level of a current model of a standard transaxle.

1-29

Automotive Technology: A Systems Approach, 3Ce 3. Using Pascal’s law and applying the formula given in the textbook (under “Laws of Hydraulics”), calculate the output forces and operating pressure of the following hydraulic system: the brake system has a master cylinder piston of 10 cm2, the input force is 40 kg, the front brake caliper pistons are 40 cm2 each, and the rear wheel cylinder pistons are 10 cm2 each. For the next part of this activity, convert all numeric values in the Pascal’s law problem to imperial values and give the imperial values for the output force of all output pistons. Finally, sketch the hydraulic system, labelling the output pistons and indicating the output forces at each location.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. a. Newton’s first law of motion is referred to as inertia. It means that an object at rest tends to remain at rest, and an object in motion tends to remain in motion unless some force acts on it. For example, when a car is parked on a level street, it remains stationary unless it is driven or pushed. 2. b. Pascal’s law would most likely be applied in the brake system 3. There are six different forms of energy: chemical, electrical, mechanical, thermal, radiant, and nuclear. 4. Types of energy conversion commonly used in automobiles are chemical-to-thermal energy (as in the combustion of the fuel); chemical-to-electrical energy (as in the battery); electricalto-mechanical energy (as in the starter); thermal-to-mechanical energy (as in an internal combustion engine); mechanical-to-electrical energy (as in an alternator or AC generator); and electrical-to-radiant energy (as in lighting); and kinetic-to-mechanical-to-electrical energy (as in hybrid regenerative braking). 5. c. When energy is released to do work it is best described as kinetic energy 6. d. Weight placed evenly around the tire on a diagonal to the tires centreline will create a dynamic imbalance. A dynamic imbalance can result in a wobble or shimmy. 7. a. A tire hopping up and down best describes tire tramp. This is caused by static tire imbalance. 8. b. The nucleus of an atom contains protons and neutrons. 9. c. Work is calculated by multiplying the applied force by the distance the object moved. 10. b. Energy may be defined as the ability to do work. 11. b. The brake pedal is an example of a class 2 lever. The resistance is placed between the pivot and the effort point. 12. a. Hertz is the measurement of frequency. 13. d. Torque is defined as a twisting force that does work with a turning (or rotating) action. 14. c. Newton-metres (N.m) are a measurement term for torque. 15. b. Pascal’s law is a law referring to hydraulics. 16. c. To increase the output force in a hydraulic system, the input piston must be smaller than the output piston. 17. b. The automobile brake system converts the vehicle’s kinetic energy to heat or thermal energy. 18. d. The formula for calculating the volume of a cylinder is 3.1416 × radius × radius × stroke. 19. b. Having a small gear driving a larger gear will produce a torque increase through gearing. 20. a. Specific gravity is the heaviness or relative density of a substance compared to that of water.

1-30

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 8 Preventive Maintenance and Basic Services CHAPTER OVERVIEW This chapter covers repair orders, the basic understanding of preventive maintenance services that are performed on vehicles, and service information to aid the technician. A number of basic service procedures will be covered. This chapter will briefly cover a number of vehicle systems from a maintenance point of view.

LEARNING OUTCOMES

• • • •

Describe the information that should be included on a repair order. Explain how repair costs can be estimated. Explain how the vehicle and its systems can be defined by deciphering its VIN

Explain the importance of preventive maintenance, and list at least six examples of typical preventive maintenance services.

•

Understand the differences between the types of fluids required for preventive maintenance and know how to select the correct one for a particular vehicle.

•

Explain how the design of a vehicle determines what preventive maintenance procedures must be followed.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Repair Orders A. Computerized Shop Management Systems B. Parts Replacement C. Sublet Repairs D. Estimating Repair or Service Costs II. Vehicle Identification III. Preventive Maintenance A. Maintenance Schedules and Reminders B. Safety Inspections IV. Basic Services A. Engine Oil B. ILSAC Oil Ratings C. ACEA Oil Ratings

1-31

Automotive Technology: A Systems Approach, 3Ce D. Manufacturers’ Oil Ratings 1. Synthetic Oils 2. Maintenance 3. Oil Filter E. Cooling System 1. Coolant 2. Coolant Condition F. Drive Belts 1. V-Belt Inspection 2. V-Ribbed Belts 3. V-Ribbed Belt Inspection 4. Belt Replacement G. Stretch-Fit Belts H. Air Filters I. Battery J. Transmission Fluid 1. Manual Transmissions K. Power-Steering Fluid L. Brake Fluid M. Clutch Fluid N. Diesel Exhaust Fluid O. Windshield Wipers 1. Windshield Washer Fluid P. Tires 1. Inflation 2. Tire Rotation 3. Lug Nut Torque Q. Chassis Lubrication 1. Greases V. Hybrid Vehicles A. Maintenance VI. Additional PM Checks

ADDITIONAL TEACHING HINTS

•

Have the students pick two or three vehicles, record and decipher the VIN, and create a list of all of the fluids used for that vehicle’s maintenance.

•

Using the information in this chapter have the students create a list comparing the differences in maintenance items for a typical RWD passenger car, a pickup, a hybrid, and a typical FWD passenger car.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

A stumbling block for beginning technicians is understanding the differences between engine oils due to the fact that they all look the same. Possibly show the students two extreme viscosities and how they flow. See page 193 of Chapter 8 for reference.

1-32

Automotive Technology: A Systems Approach, 3Ce •

Students may struggle with preventive maintenance due to the fact that in most cases nothing is actually in need of repair. Attempt to locate components that will show good examples of a component that failed earlier than normal due to a lack of maintenance.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using the shop manual, identify the most up-to-date lubricant classification and the viscosity of engine oil, automatic transmission fluid, and power-steering fluid for the current year of three different manufacturers’ vehicles. 2. Have the students create a Repair Order template individually and then as a group decide on a RO template that can be used for each vehicle that enters the shop. 3. Have the students, on a continual basis, record the actual time, flat-rate time, and estimated cost of each repair that they are asked to perform during shop time in the course.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The information found in the vehicle identification number (VIN) includes the country of manufacture, the make and type of vehicle, the year of manufacture, engine type, and the body style. 2. A battery inspection should include the following: Visually inspect the battery cover and case for dirt and grease, check the electrolyte level (if possible), inspect the battery for cracks, loose terminal posts, and other signs of damage, check for missing cell plug covers and caps, inspect all cables for broken or corroded wires, frayed insulation, or loose or damaged connectors, check the battery terminals, cable connectors, metal parts, holddowns, and trays for corrosion damage or buildup—a bad connection can cause reduced current flow, check the heat shield for proper installation on vehicles so equipped. 3. Five different types of oil ratings are API (American Petroleum Insitute), SAE (Society of Automotive Engineers), ILSAC (International Lubrication Standardization and Approval Committee), ACEA (Association of Constructors of European Automobiles), and Manufacturer’s Ratings. 4. Cleaning off the outside of a zerk fitting before injecting grease prevents foreign materials such as dirt or water from being pushed into the joint. 5. The correct tire pressure is listed in the vehicle’s owner’s manual or on a decal (placard) stuck on the driver’s doorjamb. 6. d. The right to impose a mechanic’s lien can be exercised by a shop 90 days after the completion of the agreed-upon services is the correct statement regarding a mechanic’s lien. 7. d. GC is the grease classification best suited for wheel bearings. 8. a. 0W-20 is the engine oil best suited for use in a hybrid electric vehicle. 9. d. A repair quote should show the total cost of parts and shop labour, plus any shop consumables. 10. b. Checking the hybrid system’s coolant system is an additional task that should be performed when servicing a hybrid vehicle. 11. a. Viscosity measures the ability of oil to resist flow. 12. b. The VIN shown represents a 2014 Canadian-made Dodge vehicle. 13. c. 5 at – 18°C and 30 at 100°C represents a 5W-30 oil.

1-33

Automotive Technology: A Systems Approach, 3Ce 14. b. Ethylene glycol is a coolant that is green in colour. 15. d. V-belt tension should be checked at 8000 km (5000 miles) after initial run-in. 16. a. Dark particles found on a rag after checking automatic transmission oil indicates worn clutch discs. 17. d. When replacing a paper air filter element the technician should also clean out the air filter housing. 18. b. Changes to seal and gasket technology is the reason for newer manufacturer’s oil ratings. 19. c. Checking engine oil is the PM check that should be performed most often. 20. a. 1.6 mm (1/16”) is the minimum amount of tire tread allowed before replacement.

1-34

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 9 Automotive Engine Designs and Diagnosis CHAPTER OVERVIEW This chapter introduces the student to the internal combustion engine. A variety of popular designs are described and a general discussion of engine diagnosis and testing is introduced.

LEARNING OUTCOMES

• • • •

Describe the various ways in which engines can be classified. Explain what takes place during each stroke of the four-stroke cycle. Outline the advantages and disadvantages of the in-line and V-type engine designs.

Define important engine measurements and performance characteristics, including bore and stroke, displacement, compression ratio, engine efficiency, torque, and horsepower.

• • •

Outline the basics of diesel, stratified, and Miller cycle engine operation. Explain how to evaluate the condition of an engine. List and describe abnormal engine noises.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Introduction to Engines A. Engine Construction II. Engine Classifications 1. Operational Cycles 2. Number of Cylinders 3. Cylinder Arrangement 4. Valve Train Type 5. Ignition Type 6. Cooling Systems 7. Fuel Type Hint: Give examples of various engine classifications. A. Four-Stroke Gasoline Engine 1. Four-Stroke Cycle 2. Intake Stroke 4. Compression Stroke 5. Power Stroke 6. Exhaust Stroke

2-1

Automotive Technology: A Systems Approach, 3Ce 7. Four–Stroke Operating Dynamics B. Two-Stroke Gasoline Engine 1. Engine Rotation C. Combustion D. Engine Configurations 1. In-Line Engine 2. V-Type Engine 3. Slant Cylinder Engine 4. Opposed Cylinder Engine E. Camshaft and Valve Location 1. Overhead Valve (OHV) 2. Overhead Cam (OHC) F. Valve and Camshaft Operation G. Engine Location 1. Front Engine Longitudinal 2. Front Engine Transverse 3. Mid-Engine Transverse Hint: Describe changes in engine designs and discuss how engines will change in the future. H. Gasoline Engine Systems 1. Air/Fuel System 2. Ignition System 3. Lubrication System 4. Cooling System 5. Exhaust System 6. Emission Control System III. Engine Measurement and Performance A. Bore and Stroke B. Displacement C. Compression Ratio D. Engine Efficiency 1. Volumetric Efficiency 2. Thermal Efficiency 3. Mechanical Efficiency E. Torque versus Horsepower Hint: Discuss how displacement, compression, torque, and horsepower affect engine performance. F. Atkinson Cycle Engines 1. Hybrid Engines 2. Miller Cycle Engines IV. Other Automotive Power Plants A. Hybrids 1. Battery-Operated Electric Vehicles 2. Fuel Cell Electric Vehicles B. Rotary Engines V. Diesel Engines A. Construction 1. Starting 2. Sound 3. Emissions B. Homogeneous Charge Compression Ignition Engines

2-2

Automotive Technology: A Systems Approach, 3Ce 1. Dual Mode 2. Benefits C. Variable Compression Ratio Engines VI. Engine Identification A. Using Service information 1. Engine ID Tags 2. Casting Numbers 3. Underhood Label Hint: Have the students use the VIN and the underhood label to identify the model years and engine sizes of an assortment of vehicles. VII. Engine Diagnostics A. Compression Test 1. Wet Compression test B. Running Compression Test C. Cylinder Leakage Test D. Cylinder Power Balance Test E. Vacuum Tests 1. Vacuum Transducers F. Oil Pressure Testing Hint: Discuss when each of these tests would be the most useful. Describe the difference between a compression test, a cylinder leakage test, and a cylinder power balance test. VIII. Evaluating the Engine’s Condition A. Fluid Leaks B. Exhaust Smoke Diagnosis IX. Noise Diagnosis A. Using a Stethoscope B. Common Noises 1. Ring Noise 2. Piston Slap 3. Piston Pin Knock 4. Ridge Noise 5. Rod-Bearing Noise 6. Main or Thrust Bearing Noise 7. Tappet Noise 8. Abnormal Combustion Noises 9. Cleaning Carbon Deposits Hint: Describe the various noises and whether they happen at crankshaft or camshaft speed. If possible, record some normal and abnormal engine noises for playback to the students.

2-3

Automotive Technology: A Systems Approach, 3Ce

ADDITIONAL TEACHING HINTS •

Demonstrate power balance testing, then evaluate the engine’s condition. Have the students identify their family vehicles as to engine type, valve train, camshaft location, and cylinder arrangement.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

One of the biggest stumbling blocks for beginning technicians is understanding how an engine operates by creating the change of energy from chemical to mechanical. To aid in their understanding use the chapter information starting on page 221 of Chapter 9 and a cutaway of an engine if available. Operate the engine by hand through the four strokes. Use some simple chemistry examples of burning a fuel if available. If possible obtain a few single cylinder lawnmower engines for the students to disassemble. Show the similarities in these engines to an automobiles engine.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Describe the four strokes of an internal combustion engine. Make sure your description includes the direction of the movement of the piston, the position of the intake and exhaust valves, and the amount of pressure inside the cylinder. 2. Calculate the compression ratio of a four-cylinder engine that has a bore of 92 mm (3.62 in.), a stroke of 78 mm (3.07 in.), and a clearance volume of 72.26 cm3 (4.41 cu. in.). 3. Use available shop resources to create a list of vehicles using the engine technology listed above. Find at least one example of a vehicle using an Atkinson cycle engine, a Miller cycle engine, and a rotary engine. 4. Select a vehicle and write down its VIN. Using a service manual and the textbook, explain all of the information that is given in the VIN by deciphering the codes.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The combustion chamber is the space between the top of the piston and the cylinder head. It is an enclosed area in which the gasoline and air mixture is burned. 2. The four strokes are intake, compression, power, and exhaust. 3. As an engine’s compression ratio increases, there should also be an increase in the octane rating of the fuel in order to avoid abnormal combustion. Gasoline with too low an octane rating may ignite before spark occurs due to the additional heat produced by a higher compression ratio, or it may burn in an explosive and destructive manner. 4. A cylinder balance test can be used to compare the efficiency of each cylinder. Ideally, all of the cylinders should produce an equal amount of power.

2-4

Automotive Technology: A Systems Approach, 3Ce 5. Tappet noise is a term used to describe a noisy valve train. It is characterized as a light regular clicking noise, which is more noticeable at idle speed. Because the camshaft rotates at one-half crankshaft speed, valve train noises may be identified by a lower frequency. 6. a. The statement “The engine provides the rotating power to drive the wheels through the transmission and driving axle” is true. 7. a. The ignition of the fuel/air mixture begins the power stroke. 8. c. The compression ratio describes the amount that the air/fuel mixture will be compressed. 9. b. The camshaft is responsible for opening and closing the intake and exhaust valves. 10. a. A diesel engine may have a compression ratio of up to 25:1. 11. a. A cylinder leakage test is performed to pinpoint the cause of a low cylinder compression test reading. 12. c. Piston slap is a noise that is produced when the piston slaps against the cylinder wall due to excessive clearances. 13. a. The exhaust system removes burned gases and limits the noise produced by the engine. 14. b. Piston slap is generally a hollow, bell-like noise that is produced when the piston slaps against the cylinder wall due to excessive clearances. It is commonly heard when the engine is cold, and gets louder when the engine is accelerated. Shorting out the spark plug of the affected cylinder may quiet the noise. 15. c. The stroke of an engine is equal to two times the crankshaft throw. 16. c. During a cylinder leakage test of a cylinder with worn piston rings, air should be found at the oil fill port. The air from the tester will enter the crankcase past the worn piston rings and vent to the atmosphere through the oil fill port or the dipstick tube. 17. a. An oil pressure regulator valve that is defective (sticking) can cause abnormally high oil pressure. 18. b. A sharp metallic rapping sound originating from the upper portion of an engine would most likely be a piston pin knock. 19. b. A collapsed lifter would most likely not show up on either a compression or a cylinder leakage test, but would cause the cylinder to produce less power than other cylinders. 20. d. Thermal efficiency describes how well the engine converts the heat produced during combustion into usable power.

2-5

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 10 Engine Disassembly CHAPTER OVERVIEW This chapter instructs the student in engine removal and disassembly of the cylinder head and cylinder block. Identification and cleaning of engine parts and crack detection and repair are explained in depth.

LEARNING OUTCOMES

• • • • • •

Prepare an engine for removal. Remove an engine from a FWD and a RWD vehicle. Describe how to disassemble and inspect an engine. Name the three basic cleaning processes. Identify the types of cleaning equipment. Describe the common ways to repair cylinder head cracks.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Removing an Engine A. General Procedures 1. Battery 2. Hood 3. Fluids 4. Underbody Connections 5. Air-Fuel System 6. Accessories 7. Electrical Connections 8. Cooling System B. FWD Vehicles 1. Drive Axles 2. Transaxle Connections 3. Starter 4. Removing the Engine through the Hood Opening 5. Removing the Engine from Under the Vehicle C. RWD Vehicles 1. Transmission 2. Removing the Engine Hint: Divide the students into several groups. Have them find the procedure

2-6

Automotive Technology: A Systems Approach, 3Ce for removing an engine from several types of vehicles such as a FWD van and RWD light truck in the service manuals. Compare and discuss the differences as a class. II. Engine Disassembly and Inspection A. Cylinder Head Removal III. Cleaning Engine Parts A. Types of Soil Contaminants 1. Water-Soluble Soils 2. Organic Soils 3. Rust 4. Scale B. Cleaning with Chemicals 1. Chemical Cleaning Machines C. Thermal Cleaning D. Abrasive Cleaners 1. Abrasive Cleaning Methods 2. Alternative Cleaning Methods Hint: Show the labels and MSDS for the chemicals used in the lab and discuss how to safely store and use them. IV. Crack Detection and Repair 1. Dye Penetrant A. Furnace Welding Crack Repairs B. Repairing Aluminum Heads

ADDITIONAL TEACHING HINTS

• • • • •

Disassemble a cylinder block in the shop. Display samples of soil contaminants for students to view. Demonstrate chemical, abrasive, or some other cleaning method. Use and review all MSDSs for the shop chemical cleaning agents. Show how disassembled engine parts should be organized.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Student misconceptions in this area will include the lack of organizing required while disassembling a vehicle and its engine. Stress the importance of organization and the need to label and bag most components during removal and disassembly. It is possible for there to be a couple of weeks or longer before reassembling the engine and reinstalling in the vehicle. Refer to page 258 of Chapter 10 for information.

2-7

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Choose two vehicles, one FWD and one RWD, each made by a different manufacturer, and compare the engine disassembly procedures given in their service information. Describe the similarities and the differences and explain why there are differences. 2. List all of the engine-cleaning equipment and solvents that are available in your shop. When listing the solvents, include the health-related precautions listed on the solvent container’s label or on its MSDS. Also determine how the waste-cleaning agents are to be disposed of when they need to be replaced. CASE STUDY 3. A technician is preparing to rebuild a 2.4-litre engine from a 2011 Buick Regal. After removing the heads, what procedure should be performed before removing the pistons from the block, and why?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. All electronic and fuel injection parts should be covered with plastic bags during steam or other cleaning procedures to avoid direct contact with steam, water, or other cleaning agents. Environmental regulations should always be followed. 2. Wear protective gloves and goggles when using chemical cleaners. 3. The best method for repairing cracked cast-iron heads is furnace welding by a specialist. 4. The typical steps for removing an engine from a rear-wheel-drive vehicle involves performing all the usual steps involved in engine removal such as electrical, fuel, exhaust, and hose removal. A typical RWD vehicle has the engine removed through the hood opening. If the engine is to be removed separately from the transmission, the transmission must be supported and disconnected from the engine. If the transmission and engine are to be removed together, the transmission must be drained and all linkage, cables and electrical connections must be removed and a floor jack placed under the transmission. The engine hoist should now be put in place and the engine (and transmission) mounts should be disconnected. At this point the engine or engine/transmission assembly can be carefully lifted from the vehicle. 5. a. The most common method of removing an engine from a front-wheel-drive vehicle is to lower the engine and transaxle as an assembly with the cradle. 6. a. Removing the intake and exhaust manifolds is usually the first step in engine disassembly. 7. d. For front wheel drive vehicles, a frame contact hoist bay is usually recommended. This hoist allows the engine to be lowered to the floor and the vehicle lifted to allow the engine to be removed from underneath the vehicle. 8. b. The next step would be to relieve the pressure in the fuel system. 9. d. When removing a cylinder head, a breaker bar should be used to loosen each head bolt one or two turns starting from the outside of the cylinder head working inward. 10. b. The buildup of minerals and deposits is called scale. 11. a. Hydrocarbon based solvents are toxic as well as flammable. 12. b. Grit media blasting is used to etch the surface of a material. 13. d. Tungsten inert gas (TIG) welding is the only crack repair method used on aluminum engine components. 14. a. Ultrasonic cleaning uses high-frequency sound waves to loosen dirt particles.

2-8

Automotive Technology: A Systems Approach, 3Ce 15. c. Spray washers are often used to pre-clean engine components prior to disassembly. 16. d. There is no particular order to loosening connecting rod cap bolts. 17. c. Use at least four bolts to mount an engine block to an engine stand. 18. d. After the fuel system is depressurized the negative battery cable should be disconnected. 19. c. Removal of the engine mount bolts should only be done once the supports or crane is in place. 20. a. You should vee out the damaged area and weld with an aluminum filler rod on an aluminum head with a crack in the coolant passage.

2-9

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 11 Lower End Theory and Service CHAPTER OVERVIEW This chapter discusses the cylinder block, crankshaft, crankshaft bearings, connecting rods, pistons and rings, oil galley, core plugs, flywheel, and harmonic balancer, focusing attention on the design and function of these essential parts.

LEARNING OUTCOMES

• • • • • • • • • • • • •

Disassemble and inspect an engine’s cylinder block. List the parts that make up a short block and briefly describe their operation. Describe the major service and rebuilding procedures performed on cylinder blocks. Describe the purpose, operation, and location of the camshaft. Describe the four types of camshaft drives. Inspect the camshaft and timing components. Describe how to install a camshaft and its bearings. Explain crankshaft construction, inspection, and rebuilding procedures. Explain the function of engine bearings, flywheels, and harmonic balancers. Explain the common service and assembly techniques used in connecting rod and piston servicing. Explain the purpose and design of the different types of piston rings. Describe the procedure for installing pistons in their cylinder bores. Inspect, service, and install an oil pump.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Short Block Disassembly A. Cylinder Block Disassembly II. Cylinder Block A. Lubrication and Cooling III. Cylinder Block Reconditioning A. Deck Flatness B. Cylinder Walls C. Cylinder Bore Inspection D. Cylinder Bore Surface Finish

2-10

Automotive Technology: A Systems Approach, 3Ce 1. Cylinder Deglazing 2. Cylinder Boring 3. Cylinder Honing E. Lifter Bores F. Checking Crankshaft Saddle Alignment G. Installing Core Plugs 1. Disc- or Dished-Type 2. Cup-Type 3. Expansion-Type Hint: Show examples of each type of plug and describe their proper uses. IV. Camshaft A. Valve Timing Terminology 1. Lobe Terminology B. Timing Mechanisms 1. Gear Drive 2. Chain Drive 3. Belt Drive 4. Tensioners 5. Variable Valve Timing C. Valve Lifters 1. Operation of Hydraulic Valve Lifters D. Camshaft Bearings E. Balance Shafts V. Inspection of Camshaft and Related Parts A. Timing Components B. Lifters C. Camshaft VI. Installing the Camshaft and Related Parts A. Camshaft Bearings B. Camshaft VII. Crankshaft A. Crankshaft Torsional Dampers 1. Harmonic Balancer 2. Fluid Damper B. Flywheel 1. Flywheel Inspection Hint: Show students different crankshaft configurations. Show both forged and cast crankshafts. VIII. Crankshaft Inspection and Rebuilding A. Crankshaft Reconditioning B. Checking Crankshaft Straightness C. Crankshaft Bearings D. Bearing Materials E. Bearing Spread F. Bearing Crush G. Bearing Locating Devices H. Oil Grooves I. Oil Holes J. Oil Clearance K. Bearing Failure and Inspection Hint: Show students a variety of damaged and worn bearings. Discuss the

2-11

Automotive Technology: A Systems Approach, 3Ce causes of the failures. Have students look up crankshaft specifications in service manuals or information systems. IX. Installing Main Bearings and Crankshaft A. Crankshaft End Play B. Connecting Rod 1. Inspection Hint: Demonstrate the use of Plastigage and crankshaft end play measurements. X. Piston and Piston Rings A. Piston Terminology 1. Inspection B. Piston Pins C. Piston Rings 1. Compression Rings 2. Oil-Control Rings XI. Installing Pistons and Connecting Rods XII. Crankshaft and Camshaft Timing A. Camshaft End Play B. Lifters C. Oil Pump

ADDITIONAL TEACHING HINTS

• • • •

Measure deck warpage. Demonstrate deglazing and honing. Demonstrate a crankshaft inspection. Demonstrate how to use Plastigage on the main and rod bearings.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

It will be difficult for students to understand the machining processes required to rebuild an engine. Attempt to arrange a field trip to a local machine shop; this will give the students a different perspective on what it takes. Use information throughout the chapter to reinforce this knowledge. Have the students create a list of parts they believe is needed to rebuild an engine, possibly one that is apart in your shop. Do this individually and then as a group to compare.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Following the service information procedures, perform the task of cylinder deglazing. 2. Identify the various parts of a crankshaft: main bearing journals, connecting rod bearing journals, flywheel end, drive belt end, offset crankpin, and counterweights.

2-12

Automotive Technology: A Systems Approach, 3Ce 3. Identify the following parts of a piston: dome, grooves, ring lands, piston pin bore, mark (to ensure correct piston installation), piston skirt, piston thrust surface, compression ring, and oil control ring. 4. Remove the piston rings from a piston with a piston ring expanding tool. CAUTION: Do not attempt to remove a piston ring without a piston ring expanding tool. The ends of the piston ring could scratch and damage the piston. 5. Following the service information procedures, clean the ring grooves on a piston using a ring groove cleaner tool. 6. Following the service information procedures, measure piston ring gap and ring side clearance. 7. Following the service information procedures, time the camshaft to the crankshaft for an engine using sprocket and chain system. CASE STUDY 8. A technician is installing a crankshaft into a block. After checking the main bearing oil clearance, he finds the clearance to be excessive. List three factors that could be the cause and give your recommendations.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Camshaft lobe wear may be measured with an outside micrometer or with a dial indicator. 2. The deck is the top surface of the block to which the cylinder head mounts. 3. Maximum cylinder bore wear occurs at the top of the ring travel area. 4. Compression rings form a seal between the piston and the cylinder walls using combustion pressure to force the ring against the bottom edge of the ring groove. Compression rings not only prevent combustion pressure from entering the crankcase but they also help prevent oil from entering the combustion chamber. 5. a. Hydraulic lifters automatically compensate for changes in engine temperature. 6. b. Aluminum pistons are most commonly used in automotive engines. 7. b. The initial purpose of core plugs is to allow the release of sand from the inside of the engine block during the moulding process. 8. c. A straightedge and feeler gauge is generally used to measure cylinder block deck warpage. 9. b. A micrometer is generally used to measure crankshaft bearing journals. 10. c. Roller lifters produce the least amount of camshaft wear. 11. a. Excessive piston clearance can cause piston slap. 12. b. Cylinders are deglazed to ensure proper ring sealing. 13. b. Bearing crush refers to each half of a split bearing being slightly greater than an exact half. Bearing spread means that the distance across the parting edges of the insert should be slightly greater than the diameter of the bearing bore. 14. d. The connecting rod journal is also called the crank pin. 15. d. Main bearing bore misalignment can be corrected by line boring the bearing saddles. 16. d. The correct procedure for boring cylinders is to bore the cylinder to the new piston size and hone to the proper clearance specification. 17. c. A rigid hone should be used during the boring process to maintain straight cylinder walls.

2-13

Automotive Technology: A Systems Approach, 3Ce 18. b. The correct replacement bearing for this connecting rod journal would be U/S— 0.254 mm (0.010 in.) undersize. The bearing is identified as undersize because they are named after the shaft size that they fit. 19. c. To calculate cylinder bore taper a reading must be taken at the top and bottom of ring travel at 90° to the block centreline (c/l). Greater cylinder wear occurs at 90° to the block c/l. 20. b. The cam changes rotary motion of the camshaft into the reciprocating motion of the valves.

2-14

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 12 Upper End Theory and Service CHAPTER OVERVIEW This chapter draws attention to the different types of combustion chamber designs and intake and exhaust valves. Additional information is given about reconditioning aluminum cylinder heads, resurfacing cylinder heads, grinding valves, valve guide reconditioning, and reconditioning of valve seats.

LEARNING OUTCOMES

• • • • • • •

Describe the purpose of an engine’s cylinder head, valves, and related valve parts. Describe the types of combustion chamber shapes found on modern engines. Know why there are special service procedures for aluminum and OHC heads. Describe the different ways that manufacturers vary valve timing. Perform a complete inspection on valve train components. Explain the procedures involved in reconditioning cylinder heads, valve guides, valve seats, and valve faces. Explain the steps in cylinder head reassembly.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Cylinder Head A. Ports II. Combustion Chamber A. Wedge Chamber B. Hemispherical Chamber C. Pentroof Chamber Hint: Show examples of different combustion chamber designs. III. Intake and Exhaust Valves A. Valve Construction 1. Stainless Steel Valves 2. Inconel Valves 3. Stellite Valves 4. Sodium Filled 5. Titanium Valves 6. Ceramic Valves 7. Valve Terminology B. Valve Stems

2-15

Automotive Technology: A Systems Approach, 3Ce C. Valve Seats D. Important Valve Components of Four-Stroke Engines 1. Valve Guides 2. Valve Springs, Retainers, and Seals 3. Valve Rotators 4. Camshaft Bearings 5. Pushrods Hint: Show some failed pushrods. Explain what to look for when examining pushrods. 6. Pushrod Guide Plates 7. Rocker Arms E. Multivalve Engines IV. Variable Valve Timing A. Staged Valve Timing B. Continuously Variable Timing 1. Toyota’s VVT-i System 2. Fiat’s Multiair System 3. Valvetronic System C. Other VVT Systems D. Cylinder Deactivation 1. Honda 2. Other Cylinder Deactivation Systems V. Cylinder Head Disassembly VI. Inspection of Cylinder Head and Valve Train A. Timing Components B. Timing Chains C. Belt Idler Pulley D. Tensioners E. Gears and Sprockets F. Cam Phasers G. Cam Followers and Lash Adjusters H. Rocker Arms 1. Honda’s Variable Cylinder Management Rocker Arms I. Pushrods J. Retainers and Keepers K. Valve Rotators L. Valve Springs M. Cylinder Heads N. Crack Repair 1. Furnace Welding Crack Repairs 2. Flame Spray Welding 3. Repairing Aluminum Heads 4. Pinning Cracks O. Camshaft and Bearings P. Valves Hint: Show examples of each of the cylinder head and valve train components listed. Show where to look for wear patterns. VII. Aluminum Cylinder Heads A. Reconditioning Aluminum Cylinder Heads VIII. Resurfacing Cylinder Heads A. Surface Finish

2-16

Automotive Technology: A Systems Approach, 3Ce 1. Resurfacing Machines 2. Stock Removal Guidelines IX. Grinding Valves X. Valve Guide Reconditioning A. Knurling B. Reaming and Oversized Valves C. Thin-Wall Guide Liners D. Valve Guide Replacement 1. Integral Guides 2. Insert Guides Hint: Compare reaming and oversized valves with thin-walled and castiron inserts. XI. Reconditioning Valve Seats A. Installing Valve Seat Inserts 1. Reconditioning Integral Seats 2. Grinding Valve Seats 3. Cutting Valve Seats 4. Machining Valve Seats Hint: Show a valve seat insert and describe the method used to install it. XII. Valve Stem Seals A. Installing Positive Valve Seals B. Installing Umbrella-Type Valve Seals C. Installing O-Rings Hint: Discuss the merits of positive seals over other types. D. Valve Springs 1. Freestanding Height Test 2. Spring Squareness Test 3. Open/Close Spring Tension Test Hint: Discuss why valve springs need to be tested and the consequences of omitting this service. Show examples of failed valve springs. XIII. Assembling the Cylinder Head A. OHC Engines

ADDITIONAL TEACHING HINTS

• • • • • • •

Demonstrate carbon removal and cleaning techniques. Check the head surface for warpage with a straightedge and feeler gauge. Pass around a valve with a too-narrow margin. Demonstrate how to check for valve spring tensions. Check for cam bore warpage on an OHC head. Demonstrate cylinder head disassembly and reassembly. Demonstrate how disassembled cylinder head parts should be organized.

2-17

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

Students will typically have a difficult time understanding the machining processes required to recondition a cylinder head to the point where it is able to be reused. There are a large number of measurements required to perform these tasks. Using information from throughout the chapter and a used cylinder head, take the students through all of the processes required from disassembly right through to reassembly of just one cylinder’s valve train.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using a service information system, describe the components of the valve assembly for five different engines. Identify the differences—for example, some have more than one valve spring per valve—and explain why these differences exist. To benefit from this activity, you should have a variety of the type of engines and the engine manufacturers that you will use in this study. 2. Identify the following parts in a cylinder head: valves, valve seats, valve guides, valve springs, rocker arm supports, the recessed area that makes up the top position of the combustion chamber, and (on an overhead cam engine only) the supports for the camshaft and camshaft bearings. 3. Identify two different types of variable valve timing or cylinder deactivation systems and list all of the components involved in their operation. CASE STUDIES 4. A customer brings her 2010 Ford Focus into the shop and complains that the engine is using too much oil. She presents a log of when oil was added. The log certainly verifies her complaint. The technician carefully inspects the engine for leaks and finds none. What should she do next? 5. A customer brings in a 2011 Chevrolet HHR with valve noise. List, in proper sequence, the first three checks the technician should make.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. If valve spring tension is too low, the valves will not be closed promptly enough and there will be valve float at higher engine speeds. 2. Valve margin is the area between the valve face and the head of the valve that allows for some machining of the valve face, which is sometimes necessary to restore its finish, and allows the valve an extra capacity to hold heat. 3. Warpage in an aluminum cylinder head is usually the result of overheating or uneven cooling within the cylinder head. 4. Pushrods may be checked for straightness while installed in the engine by rotating them when the valve is closed and visually checking for indications of wobble. When the pushrods are out of the engine, they can be checked by rolling them on a flat surface; a pushrod that is not straight will appear to hop. The most accurate method is by using a dial indicator. If more than 0.003 (0.076 mm) TIR is found, the pushrod should be replaced.

2-18

Automotive Technology: A Systems Approach, 3Ce 5. Because knurling only restores a portion of the valve guides ID to original dimensions. The raised edges produced by knurling soon wear down, and clearances rapidly become excessive. 6. b. The margin is the distance between the valve face and the valve head. 7. d. Oil can leak into the intake charge and the exhaust gases when the valve guide is worn. The air flow into the cylinder during the intake stroke can pull oil down the intake valve guide and into the combustion chamber. The exhaust gas flow past the guide can also draw oil into the exhaust gases. 8. c. Bronze valve guides tend to last 2 to 5 times longer than cast iron guides due to its ability to retain oil and their anti-wear and anti-seize characteristics. 9. c. A wider than specified valve seat can be narrowed by using a three angle valve grind. A topping stone will remove material from the outer edge of the seat and a throating stone will remove material from the inner edge. 10. d. Positive valve stem seals fit tightly over the guide and removes excess oil off the valve as it moves up and down through the seal. 11. b. A valve seat insert should be staked after installation to secure it in the counterbore. 12. a. Rocker arm ratio is used to open the valve further than the cam lobe lift. 13. a. The interference angle is the one degree angle difference between the valve face and the valve seat. 14. a. Shims are placed under the valve springs to restore the correct valve spring installed height. When the valve and seat is machined material is removed from both resulting in the valve stem extending further through the head. A shim is used to counter this extra stem height. 15. a. In general, maximum cylinder head deck surface deformation is 0.1 mm (0.004 in.). 16. c. Installing new valve guide inserts would be the first procedure performed. The valve seats can only be cut or ground after the guide is repaired because the seat must be concentric to the guide centreline. 17. c. Broaching machines use an underside rotary cutter. 18. b. The ideal intake valve seat width 1.6 mm (1/16 in.). 19. d. Quenching is the cooling of gases by pressing them into a thin area. 20. d. The exhaust valve margin should be greater than 1.14 mm (0.045 in.). An exhaust valve with a thinner margin could burn during operation.

2-19

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 13 Engine Sealing and Reassembly CHAPTER OVERVIEW This chapter describes the gaskets, sealants, adhesives, and fasteners needed to correctly seal an engine. Improvement in sealing technologies is introduced in this chapter. Proper engine reassembly procedures are also covered in detail.

LEARNING OUTCOMES

• • • • • • •

Explain the purpose of the various gaskets used to seal an engine. Identify the major gasket types and their uses. Explain general gasket installation procedures. Describe the methods used to seal the timing cover and rear main bearing. Reassemble an engine including core plugs, bearings, crankshaft, camshaft, pistons, connecting rods, timing components, cylinder head, valve train components, oil pump, oil pan, and timing covers. Explain the ways to prelubricate a rebuilt engine. Reinstall an engine and observe the correct starting and break-in procedures.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Torque Principles A. Thread Repair B. Torque-to-Yield (TTY) Bolts II. Gaskets A. Cut Gaskets 1. Paper/Fiber Gaskets 2. Cork Gaskets B. Molded Rubber Gaskets C. Hard Gaskets D. Replacement Gaskets E. General Gasket Installation Procedures III. Specific Engine Gaskets A. Cylinder Head Gaskets 1. Bimetal Engine Requirements 2. Multilayer Steel (MLS) B. Head Gasket Failures 1. Head Bolts

2-20

Automotive Technology: A Systems Approach, 3Ce C. Manifold Gaskets D. Valve Cover Gaskets E. Oil Pan Gaskets F. EGR Valve IV. Adhesives, Sealants, and Other Chemical Sealing Materials A. Adhesives B. Sealants 1. General-Purpose Sealants 2. Thread Sealants 3. Silicone Sealants 4. Anaerobic Formed-in-Place Sealants C. Antiseize Compounds Hint: Discuss the importance of using oxygen-sensor safe RTV and antiseize compounds. V. Oil Seals A. Timing Cover Oil Seals B. Rear Main Bearing Seals Hint: Discuss oil seal burning and emphasize the importance of lubricating the oil seal lip. VI. Engine Reassembly A. Installing the Cylinder Head and Valve Train 1. Torque Angle Gauge B. Timing Belts and Chains C. Final Reassembly Steps 1. Coolant Drains and Plugs 2. Timing Sensors 3. Install the Timing Cover 4. Install the Vibration Damper 5. Install the Valve Cover 6. Install Oil Pan 7. Install Intake Manifold 8. Install the Thermostat and Water Outlet Housing 9. Install Exhaust Manifold 10. Install Flywheel or Flex Plate 11. Install Clutch Parts 12. Install Torque Converter 13. Install Engine Mounts 14. Other Parts VII. Installing the Engine A. Installing an Engine into a FWD Vehicle B. Installing an Engine in an RWD Vehicle C. Prelubrication 1. Distributor-Driven Oil Pumps D. Starting Procedure E. Break-In Procedure F. Relearn Procedures

2-21

Automotive Technology: A Systems Approach, 3Ce

ADDITIONAL TEACHING HINTS

•

Examine various metric and UNS bolts. Identify the size of the bolt head, and the diameter, length, and thread pitch of each bolt.

• • • • •

Demonstrate impression testing. Demonstrate RTV, antiseize, Loctite, and other gasket sealers. Demonstrate engine prelubrication processes. Demonstrate torque-to-yield bolt tightening. Demonstrate valve lash adjustment.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

Students entering the automotive trade will typically not have a feeling for a certain torque value. Using the torque value chart on page 371 of Chapter 13, place various fasteners into a threaded metal plate and have the students practise applying the proper torque values on these fasteners without a torque wrench and checking their accuracy. This will get them used to having a “feel” for torque values.

• Students will typically struggle with understanding which one of the many sealers or adhesives to use in each situation. Using information starting from page 380 of Chapter 13, have the students make a list of each sealer and adhesive used in an engine of their choice and why they would use each.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Refer to the service information for the engine of your choice. Find the torque specifications for the following parts: cylinder head, intake manifold, oil pan, valve (cam) covers, and water pump bolts. 2. Describe what each of the following gaskets must do or seal: cylinder head gasket, intake manifold gasket, oil pan gasket, valve cover gasket, and water pump gasket. Include in your description everything that is sealed by the gasket.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A bolt that has been stretched to its yield point will not return to its original length. 2. Cylinder head, exhaust manifold, and some intake manifold gaskets. 3. On the threads of bolts exposed to fluids. 4. Whether they cure in the presence of air (aerobic) or with the absence of air (anaerobic). Aerobic can be used where flexibility or gap filling ability is needed while anaerobic is used to seal machined surfaces of rigid components. 5. b. Bolt torque values are calculated to 25 percent below the bolts yield point. 6. d. When torquing cylinder head bolts, always follow the manufacturer’s recommendations.

2-22

Automotive Technology: A Systems Approach, 3Ce 7. a. Tightening torque-to-yield fasteners requires torquing the bolt to a specified torque followed by turning it an additional number of degrees. 8. d. Engine block bolt holes that have been pulled up should be filed flat, chamfered and the threads cleaned before it is reused. 9. a. Unless otherwise noted, coat the threads and the underside of the bolt head with engine oil. 10. b. Anaerobic sealants are used to seal machined surfaces of rigid castings. 11. c. The torque converter must be inserted over the transmission input shaft and rotated until it engages the transmission oil pump. Failure to engage the oil pump can cause damage to both the torque converter and transmission. 12. a. When starting a rebuilt engine the throttle should be set at approximately 1500 rpm until operating temperature is reached. 13. c. During the initial test run of a rebuilt engine, repeated full throttle accelerations from 50 to 80 km/h (30 to 50 mph) should be performed. This will result in accelerated ring seating. 14. a. Graphite is a lubricant that will allow the head to slide across the gasket as it expands and contracts. 15. c. Mechanical flat base lifters require valve train adjustment. 16. a. RTV sealants can be used to replace oil pan gaskets and other flexible stampings. 17. b. Synthetic rubber lip type seals are commonly used as rear main seals on current engines. 18. c. Aluminum heads can expand two to three times more than the cast iron engine block which will produce movement between the two components. 19. d. A prelubricator should be used to prime or circulate engine oil throughout a rebuilt engine before the initial startup. 20. a. Not all timing belt tensioners require adjustment.

2-23

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 14 Lubricating and Cooling Systems CHAPTER OVERVIEW This chapter describes the functions of the components of a typical lubricating and cooling system. Also explained are service requirements such as oil types, oil pump inspection and installation, and cooling system inspection and service.

LEARNING OUTCOMES

• • • • • • •

Name and describe the components of a typical lubricating system. Inspect, service, and install an oil pump. Describe the purpose of a crankcase ventilation system. List and describe the major components of the cooling system. Describe the operation of the cooling system. Describe the function of the water pump, radiator, radiator cap, and thermostat in the cooling system. Test and service the cooling system.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Lubrication System A. Engine Oil 1. Oil Pump 2. Types of Oil Pumps 3. Pressure Regulation 4. Oil Pan or Sump 5. Pan Baffles 6. Dry Sump 7. Oil Filter B. Oil Coolers C. Engine Oil Passages or Galleries D. Dipstick E. Oil Pressure Indicator II. Oil Pump Service A. Inspection 1. Pickup Unit III. Installing the Oil Pump ©2016 Nelson Education Ltd.

2-24

Automotive Technology: A Systems Approach, 3Ce A. Crankshaft-Driven Pump B. Cam-Driven Pumps 1. Distributor-Driven Pump IV. Basic Lubrication System Diagnosis and Service A. Oil Passages, Galleries, and Lines B. Oil Consumption 1. Oil Usage 2. Sludge C. Flushing the System D. Oil Cooler V. Cooling Systems A. Coolant B. Thermostat C. Water Pump 1. Electric Water Pumps D. Radiator 1. Transmission Cooler E. Radiator Pressure Cap 1. Expansion Tank F. Hoses 1. Water Outlet 2. Water Jackets G. Hose Clamps H. Belt Drives I. Heater System J. Cooling Fans 1. Electric Cooling Fans K. Hydraulic Cooling Fans 1. Temperature Sensors L. Temperature Indicators M. Engine Block Heaters VI. Cooling System Diagnosis A. Testing for Electrolysis in Cooling Systems B. Overheating C. Effects of Overheating D. Temperature Test E. Radiator Checks F. Checking and Replacing Hoses G. Belt Drives H. Checking Fans and Fan Clutches 1. Electric Cooling Fans I. Testing the Thermostat J. Water Pump Checks K. Testing for Leaks L. Pressure Testing 1. Leak Detection with Dye 2. Combustion Leak Check M. Testing the Radiator Pressure Cap N. Water Outlet VII. Cooling System Service A. Hoses

2-25

Automotive Technology: A Systems Approach, 3Ce 1. Hose Clamps B. Thermostat C. Repairing Radiators 1. Replacing the Water Pump D. Draining the Coolant E. Coolant Recovery and Recycle System F. Flushing Cooling Systems 1. Flushing Chemicals G. Refilling and Bleeding H. Special Precautions for Hybrid Vehicles I. Coolant Exchangers Hint: Show examples of various hose and belt failures. Cut an upper radiator hose lengthwise so that students can see how hoses begin to deteriorate from the inside first. Show a hose with ECD. Demonstrate testing a thermostat for opening temperature and for sticking.

ADDITIONAL TEACHING HINTS

• • • • •

Examine and discuss an oil pump pressure valve. Examine an oil pressure system, pointing out the location of sending units, oil lines, and gauges. Completely inspect several types of oil pumps according to manufacturer’s recommendations. Examine the various types of radiator core constructions. Pressure test the cooling system for leaks.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Students may have a hard time understanding the importance of both the lubrication and cooling systems. Within reason both systems can survive a long time with no maintenance. Assemble a number of failed components from an engine that has had little or no maintenance to either the lubrication or cooling system. Using the information on page 422 of Chapter 14, have the students drain the cooling system and remove a number of cooling hoses to examine the degradation of the hoses on their inner liner. Discuss the causes of this electrochemical degradation.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On a vehicle, locate and identify as many of the following parts of the lubrication system as you can: oil pump, oil pan, oil filter, oil cooler, oil pressure switch or sending unit, dipstick, oil filler cap, and PCV valve. 2. As more of today’s higher performance vehicles are using dry sump oil systems, use a vehicle in your shop and locate the components used in a dry sump oil system. If a vehicle isn’t available, use service information to list the components.

2-26

Automotive Technology: A Systems Approach, 3Ce 3. On a vehicle, locate and identify as many of the following parts of the cooling system as you can: water pump, radiator, heater core, lower radiator hose, upper radiator hose, heater hoses, radiator pressure cap, coolant expansion tank, and engine coolant temperature sensor or sending unit. 4. Using a hybrid vehicle, locate as many of the cooling system components as possible. Focus on the system components that would be particular to a hybrid: electric in-line water pump, special coolant reservoir, special air bleeder on inverter. NOTE: Be cautious working around high-voltage components. Review the section in the text referring to working around hybrid vehicles. CASE STUDY 5. A technician is testing the cooling system on a 2012 Dodge Ram 1500. While testing for internal leakage, the gauge jumped suddenly and showed an excessively high pressure. What three faults could cause this to happen?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The basic design, area, the radiator core thickness, coolant flow through the radiator and the temperature of the outside air flowing through it will all influence the radiator’s efficiency. 2. The closed system type radiator cap is the one that is most commonly used. 3. To determine whether the water pump is creating good circulation, warm up the engine and run it at idle speed. Squeeze the upper radiator hose with one hand and accelerate the engine with the other. If a surge of coolant is felt at the hose, the pump is circulating coolant. 4. The oil pump is typically driven by the crankshaft or camshaft. 5. The pressure regulator valve. 6. a. The full flow oil filter bypass valve should open when the filter element becomes clogged. 7. b. Increased bearing clearances reduce resistance to oil flow and increase the volume of oil circulating through the engine. 8. c. One of the main purposes of the cooling systems thermostat is to bring the engine to operating temperature quickly. It also tries to control the engines minimum operating temperature. 9. b. The vacuum valve in the radiator cap allows coolant to return to the radiator from the overflow tank. This occurs when the coolant in the cooling system cools and contracts. 10. a. The temperature of the engine controls the cycling of the electric cooling fan. The coolant temperature sensor monitors coolant temperature and cycles the fan on and off. 11. c. The fan shroud concentrates the airflow through the radiator. 12. b. 13. d. The conventional pellet type thermostat is installed with the pellet positioned toward the engine. This allows the pellet to better sense internal engine coolant temperature. 14. b. Every 6.89 kPa (1 pound) of pressure on engine coolant raises the boiling point approximately 1.66°C (3°F). 15. b. Automotive water pumps are usually belt driven from the crankshaft. 16. d. The inner rotor to housing dimension is not measured, but the clearance between the outer rotor and housing is checked with feeler gauges. 17. d. Premature bearing and bushing failure in water pumps, generators, and power steering pumps results from excessive belt tension, not insufficient tension as stated.

2-27

Automotive Technology: A Systems Approach, 3Ce 18. c. A thermostat must be fully open when it is 11.1°C (20°F) above its opening temperature. 19. a. The recommended antifreeze/water mixture for freeze-up and corrosion protection in moderate climates is 50 percent antifreeze and 50 percent water. Stronger mixtures are recommended for colder climates. 20. c. A defective oil pressure regulator valve could cause abnormally high engine oil pressure. Higher viscosity oil could cause slightly higher oil pressure readings but the regulator valve should limit the maximum pressure.

2-28

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 15 Basics of Electrical Systems CHAPTER OVERVIEW This quite technical chapter forms a foundation for the electrical systems covered in Chapters 16 through 23. The first five pages of Chapter 6 can be reviewed in conjunction with this chapter.

LEARNING OUTCOMES • • • • • • • •

Explain the basic principles of electricity. Define the terms normally used to describe electricity. Use Ohm’s law to determine voltage, current, and resistance. List the basic types of electrical circuits. Describe the differences between a series and a parallel circuit. Name the various electrical components and their uses in electrical circuits. Describe the different kinds of automotive wiring. Explain the principles of magnetism and electromagnetism.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Basics of Electricity A. Flow of Electricity II. Electrical Terms A. Alternating Current B. Circuit Terminology C. Power Sources D. Ohm’s Law E. Power III. Conductors and Insulators A. Circuits 1. Series Circuits 2. Parallel Circuits 3. Series-Parallel Circuits B. Grounding the Load Hint: Show examples of the different types of circuits and show how they differ. Have the students practise taking voltage and resistance measurements with each type of circuit and compare their results to calculated values. IV. Circuit Components A. Resistors B. Circuit Protective Devices 1. Fuses 2. Fuse Links

3-1

Automotive Technology: A Systems Approach, 3Ce 3. Maxi Fuses and Pacific Fuses 4. Circuit Breakers 5. Solid State Circuit Breakers 5. 42-Volt Systems 6. Voltage Limiter C. Switches D. Solenoids E. Relays F. Capacitors G. Wiring 1. Flat Wiring 2. Printed Circuits Hint: Show examples of each of the circuit components listed. V. Electromagnetism Basics A. Fundamentals of Magnetism 1. Flux Density 2. Coils B. Magnetic Circuits and Reluctance C. Induced Voltage Hint: Discuss the role that magnetism plays in automotive systems.

ADDITIONAL TEACHING HINTS

• • • • •

Demonstrate how to perform voltage, amperage, resistance, and frequency measurements and how to perform a voltage drop test. Examine several electrical components and explain how each works. Demonstrate the features of a typical DMM and show how and when to use each one. Demonstrate proper wire repair and terminal replacement, including soldering techniques. Show examples of high resistance connections and intermittent circuits.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

The basic knowledge of electricity has always been a very large stumbling block for automotive technicians. The most difficult part of working with electricity is that it cannot be seen, only its results can be seen. With this in mind, use the large amount of information in chapter 15 relating to the basic building blocks of electricity and have the students create simple circuits and see the effects of current flow. Have them add light bulbs in series and parallel and watch the lights react. Creating these visual aids will help cement the concepts in their mind.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using Ohm’s law, solve the following problems:

3-2

Automotive Technology: A Systems Approach, 3Ce Problem 1—Series Circuit Refer to the circuit in Figure 15–1.

Figure 15–1. A series circuit. Calculate the following values, when R1 = 2 ohms and R2 = 4 ohms: Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Voltage drop across R1 = volts. Voltage drop across R2 = volts. If the resistance of R1 is increased to 8 ohms, what are the new values? Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Voltage drop across R1 = volts. Voltage drop across R2 = volts.

3-3

Automotive Technology: A Systems Approach, 3Ce Problem 2—Parallel Circuit Refer to the circuit in Figure 15–2.

Figure 15–2. A parallel circuit. Calculate the following values, when R1 = 3 ohms and R2 = 6 ohms: Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Voltage drop across R1 = volts. Voltage drop across R2 = volts. Problem 3—Parallel Circuit Refer to the circuit in Figure 15–2 above again. Calculate the following values when R1 = 12 ohms and R2 = 12 ohms: Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Voltage drop across R1 = ___ volts. Voltage drop across R2 = ___ volts.

3-4

Automotive Technology: A Systems Approach, 3Ce Problem 4—Parallel Circuit Refer to the circuit in Figure 15–3.

Figure 15–3. A two-branch parallel circuit. Calculate the following values when R1 = 1 ohm, R2 = 3 ohms, R3 = 2 ohms, and R4 = 2 ohms: Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Current through R3 = ___ amps. Current through R4 = ___ amps. Voltage drop across R1 = volts. Voltage drop across R2 = volts. Voltage drop across R3 = volts. Voltage drop across R4 = volts.

3-5

Automotive Technology: A Systems Approach, 3Ce Problem 5—Parallel Circuit Refer to the circuit in Figure 15–4.

Figure 15–4. A three-branch parallel circuit. Calculate the following values when R1 = 2 ohms, R2 = 3 ohms, and R4 = 6 ohms: Total circuit resistance = ___ ohms. Circuit current = ___ amps. Current through R1 = ___ amps. Current through R2 = ___ amps. Current through R3 = ___ amps. Voltage drop across R1 = ___ volts. Voltage drop across R2 = ___ volts. Voltage drop across R3 = ___ volts.

3-6

Automotive Technology: A Systems Approach, 3Ce Problem 6—Series-Parallel Circuit Refer to the circuit in Figure 15–5.

Figure 15–5. A series-parallel circuit. Calculate the following values, when R1 = 1 ohm, R2 = 2 ohms, R3 = 3 ohms, and R4 = 6 ohms: Total circuit resistance = ___ ohms.

Current through R4 = ___ amps.

Circuit current = ___ amps.

Voltage drop across R1 = ___ volts.

Current through R1 = ___ amps.

Voltage drop across R2 = ___ volts.

Current through R2 = ___ amps.

Voltage drop across R3 = ___ volts.

Current through R3 = ___ amps.

Voltage drop across R4 = ___ volts.

2. Convert the following values into the electrical units noted: 1. 3.7 K ohms = ___ ohms

11. 2100 ohms = ___ K ohms

2. 641 millivolts = ___ volts

12. 0.000 175 amps = ___ milliamps

3. 7.83 K ohms = ___ ohms

13. 0.897 volts = ___ millivolts

4. 4 milliamps = ___ amps

14. 9 K volts = ___ millivolts

5. 17 K ohms = ___ ohms

15. 376 539 ohms = ___ K ohms

6. 3.9 milliamps = ___ amps

16. 144 000 milliamps = ___ amps

7. 274 milliamps = ___ amps

17. 328 millivolts + 11.672 volts = ___ volts

8. 2391 millivolts= ___ volts

18. 265 000 ohms = ___ ohms

9. 0.436 K ohms= ___ ohms

19. 0.000 033 amps = ___ milliamps

10. 37 K ohms + 826 ohms= ___ ohms

20. 12 600 millivolts = ___ volts

3. Acquire a set of jumper wires, an in-line fuse holder, a 12-volt power source, and two 12-volt automotive style lamps to create a circuit with the lamps connected in parallel.

3-7

Automotive Technology: A Systems Approach, 3Ce Measure the voltage of the battery, measure the resistance of the components involved and using Ohm’s law calculate the voltage, current flow, and resistance of the circuit. Having calculated the current flow in the circuit, acquire the appropriate size of fuse for the fuse holder. Build the circuit and, using a DVOM, measure and record the voltage, as well as current flow in the circuit. Compare your readings to the calculated values.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. b. Current flow is constant throughout a series circuit. 2. c. Ohm’s law states that current is directly proportional to voltage. 3. d. Multi-strand copper core wire is the most common type of automotive wiring. 4. b. The size of the wire will have the greatest effect on resistance. If a wire size is doubled the resistance would be cut in half. 5. a. When NC is shown on a switch it refers to the switch being normally closed. This means that current will be conducted or flow through the switch in the at-rest state. 6. b. A rheostat is a variable resistor. Rheostats have two connections, one to the fixed end of the resistor and one to a sliding contact with the resistor. 7. b. 1 amp of current will flow through a series circuit with two 20 ohm resistors and 20 volts applied (20 volts ÷ 20 ohms = 1 amp). 8. a. The total resistance of a series circuit with 12 volts applied and 0.5 amps of current will be 24 ohms (12 volts ÷ 0.5 amps = 24 ohms). 9. c. Adding another resistor to a series circuit would reduce the voltage drop across each resistor. 10. d. By adding another load in parallel to a parallel circuit, the total current flow would increase. 11. d. The total resistance of a parallel circuit will always be less than the smallest resistor. 12. c. The current flow in a 12-volt circuit with two 6 ohms resistors connected in parallel would be 4 amps. Each branch would have a current flow of 2 amps. 13. a. A 12-volt parallel circuit with resistances of 6, 3, and 2 ohms would have a total resistance of 1 ohm. 14. d. A circuit protection device works by limiting amperage. 15. d. Power consumption would not change from a 12-volt system to a 42-volt system. The benefit to a 42-volt system would be the reduction in current flow. 16. d. 24 watts of power would be consumed. Power is equal to voltage multiplied by amperage (12V × 2A = 24W). 17. c. Induction creates voltage. Voltage is induced in a wire when a wire is moved across a magnetic field. 18. a. A circuit breaker is a protection device that can be reset. Some circuit breakers are cycling, meaning they will reset automatically or noncycling, which require manual resetting. 19. b. SPST refers to a single pole, single throw switch. This is the simplest type of on/off switch and is used in a single conductor or circuit. 20. a. Wire shielding is used to protect wire from induction.

3-8

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 16 Basics of Electronics and Computer Systems CHAPTER OVERVIEW This chapter explains the principles of operation and the components used in onboard computers and other electronic systems.

LEARNING OUTCOMES • • • • • • • • • • • • •

Understand the purpose and operation of a capacitor. Describe how semiconductors, diodes, and transistors work. Explain the advantages of using electronic control systems. Explain the basic function of the central processing unit (CPU). List and describe the functions of the various sensors used by computers. Explain the principle of computer communications. Summarize the function of a binary code. Name the various memory systems used in automotive computers. List and describe the operation of output actuators. Explain the principle of multiplexing. Describe the precautions that must be taken when diagnosing electronic systems. Perform a communications check on a multiplexed system. Reprogram a control module in a vehicle.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Capacitors A. Operation II. Semiconductors A. Hole Flow B. Diodes C. Transistors D. Field-Effect Transistors E. Integrated Circuits Hint: Show a circuit board with integrated circuits. Talk about how many circuits and components may be present in one IC chip. III. Computer Basics A. Inputs 1. Reference Voltage Sensors 2. Voltage-Generating Sensors B. Communication Signals 1. Schmitt Trigger 2. Clock Rate

3-9

Automotive Technology: A Systems Approach, 3Ce 3. Communication Rates C. Logic Gates D. Memories 1. Read-Only Memory (ROM) 2. Programmable Read-Only Memory (PROM) 3. Random-Access Memory (RAM) E. Actuators 1. Duty Cycle versus Pulse Width F. Power Supply G. Awake/Sleep Modes IV. On-Board Diagnostics A. By-Wire Technology V. Multiplexing A. Advantages B. Types of Multiplexing C. Communication Protocols D. CAN Buses VI. Protecting Electronic Systems VII. Diagnosing BCMs A. Trouble Codes B. Communication Checks C. Bus Wire Service D. Reprogramming Control Modules VIII. Testing Electronic Circuits and Components

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Most entry level automotive students will have had little or no exposure to on-board control systems or electronics that make them work. Attempt to illustrate that “solid state” devices can accomplish the same tasks as conventional electrical items by creating a wiring circuit using a diode or a transistor to operate a light or some other device. Have the students refer to the chapter information relating to diodes and transistor operation starting on page 468 to explain the circuit operation. The computer logic functions of input, process, storage, and output will be a difficult idea to understand. Use every day analogies such as how any person uses these very same steps throughout their day to make decisions, to help the students understand the process.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. List the components of an integrated circuit. 2. On a late-model vehicle of your choice, locate and identify five system inputs and five system outputs. Show these to your instructor. Also locate the computer. 3. Using an OBD II–equipped vehicle and a labscope, locate the DLC and identify one of the terminals of the DLC as a “bus” terminal. Attach the labscope and then operate components on the bus line you are

3-10

Automotive Technology: A Systems Approach, 3Ce monitoring. Observe the voltage changes as the modules communicate. Record the types and amounts of the voltages observed.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. c. The basic operating instructions of the computer are stored in the ROM (read-only memory). This information cannot be erased. 2. b. The computer can read from and write to the RAM (random access memory). The RAM is used during computer operation to store temporary information. 3. c. Silicon is the most common semiconductor material. A semiconductor material has less resistance than an insulator but more resistance than a conductor. 4. b. Multiplexing commonly uses 2 wires. One of the wires is a ground and the other is for data transmission. 5. c. The binary system uses two numbers, 0 and 1. “0” usually refers to off or low voltage while “1” refers to on or high voltage. 6. c. To “turn on” a NPN transistor, current must flow through the base/emitter. Positive voltage must be applied to the base for this to occur. The base/emitter flow will then allow flow through collector/emitter. 7. a. A transistor can be used as a switch in electronic circuits. 8. b. 9. b. As speed increases, the frequency of a digital signal will increase. 10. d. An NTC resistor is the most common type of coolant or air temperature sensor. 11. a. A wheel speed sensor is a voltage generating sensor. It is a type of magnetic pulse or permanent magnet (PM) generator. 12. d. As the speed increases, the frequency and amplitude from a magnetic pulse generator will also increase. Since the amplitude increases, so will the alternating voltage which means an increase in both negative and positive voltage. The computer however calculates speed based on the frequency. 13. b. A throttle position sensor (TPS) is a sensor that modifies the reference voltage signal. 14. a. To forward bias a diode, the anode must be positive and the cathode must be negative. To accomplish this, the diode’s positive side is connected to the positive side of the circuit and the negative side of the diode is connected to the negative side of the circuit. 15. d. 16. a. A strain gauge MAP sensor is an example of a Wheatstone bridge. 17. b. Pulse width is the length of time, usually measured in ms (milliseconds), during which an actuator is on. 18. c. A knock sensor is a piezo-electric device. 19. a. A gate circuit in a computer controls output based on input signals. 20. c. Magnetism turns on and off a Hall-effect switch.

3-11

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 17 General Electrical System Diagnostics and Service CHAPTER OVERVIEW Repairing nearly every system of a vehicle requires correctly diagnosing electrical and electronic systems. An understanding of how electrical/electronic systems work and the knowledge of how to use the various types of test equipment is essential to efficient diagnosis and repair.

LEARNING OUTCOMES

• • • • • • • • • •

Describe the different possible types of electrical problems. Read electrical automotive diagrams. Perform troubleshooting procedures using meters, test lights, and jumper wires. Describe how each of the major types of electrical test equipment are connected and interpreted. Explain how to use a digital multimeter (DMM) for diagnosing electrical and electronic systems. Explain how to use an oscilloscope for diagnosing electrical and electronic systems. Test common electrical components. Use wiring diagrams to identify circuits and circuit problems. Diagnose common electrical problems. Properly repair wiring and connectors.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Electrical Problems A. Open Circuits B. Shorted Circuits C. High-Resistance Circuits Hint: Demonstrate each of the common circuit faults and show each one’s effect on current flow and voltage. II. Electrical Wiring Diagrams Hint: Show some common wiring diagrams. Have the students identify the

3-12

Automotive Technology: A Systems Approach, 3Ce components by their symbols. Have students find the power and ground supply points for various circuits. III. Electrical Testing Tools A. Circuit Testers B. Multimeter C. Lab Scopes D. Scan Tools E. Other Test Equipment 1. TESlite Voltmeter Leads 2. Jumper Wires 3. Computer Memory Saver IV. Using Multimeters A. Measuring Voltage 1. Voltage Drop Test 2. Measuring AC Voltage B. Measuring Current 1. Inductive Current Probes C. Measuring Resistance 1. Continuity Tests D. MIN/MAX Readings E. Other Measurements F. Safety Guidlines Hint: Show a multimeter and describe its features. V. Using Lab Scopes A. Analog versus Digital Scopes B. Waveforms C. Scope Controls D. Graphing Multimeters 1. Transferring Data to a PC VI. Testing Basic Electrical Components A. Protection Devices 1. Fuses 2. Fuse Links 3. Maxi-Fuses 4. Circuit Breakers 5. Thermistors B. Switches C. Relays D. Stepped Resistors E. Variable Resistors F. Wiring G. Printed Circuits Hint: Display several different examples of each of the basic electrical components. VII. Troubleshooting Circuits A. Troubleshooting Logic B. Using Wiring Diagrams 1. Getting The Right Diagram 2. Tracing a Circuit VIII. Testing For Common Problems A. Testing for Opens

3-13

Automotive Technology: A Systems Approach, 3Ce B. Testing for Shorts 1. Short Detector C. Testing For Unwanted Resistance Hint: Demonstrate how each of the preceding conditions can be diagnosed using several types of test equipment such as multimeters and test lights. IX. Connector and Wire Repairs A. Replacement Wire Selection B. Connecting Wires C. Wire Terminals and Connectors D. Replacing a Terminal

ADDITIONAL TEACHING HINTS

• Show the meters and test equipment the students will be using and demonstrate their features and proper use.

• Show an example of an electronic component such as a computer or similar control module that has failed due to using the wrong test equipment or due to static electricity. Caution the students on how to avoid such damage.

• • • •

Provide a collection of known good and known bad components and have the students practise testing them. Demonstrate the use of solder and shrink tubing to perform wiring repairs. Assign the students a project using solder to demonstrate their skill. Demonstrate the use of wiring diagrams. Explain the common symbols. Assign a lab project requiring the students to locate and identify power and ground sources and control circuits. Construct a parts identification board with examples of common electronic components. Test the students on their ability to identify and test each component.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

• •

Beginning automotive technicians will struggle testing electrical circuits for a few reasons, simply understanding the theory of electrical basics is the first hurdle, then they must understand how to read a wiring diagram, and then they must learn how to use and interpret the test equipment available to them. To overcome some of these issues have the students create a simple electrical circuit, then have them draw the circuit using proper symbols and finally have them create a diagnostic strategy to test this simple circuit. Use reference material from throughout the chapter to aid in this project. Recognizing the effects of electrical problems on a circuit will help students properly diagnose faults, create an example of each of these faults and have the students use information starting on page 493 of Chapter 17 to analyze each problem.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using a soldering iron, 60/40 rosin core solder, a 30.5 cm (12-in.) length of red wire, a 30.5 cm (12-in.) length of black wire, four pieces of appropriate shrink tube, and four alligator clips, solder and shrink-

3-14

Automotive Technology: A Systems Approach, 3Ce tube two jumper wires that can be used as test leads in further electrical diagnosis. As an option to this activity, solder in fuse holders to each of the jumper wires.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. b. The result of an open circuit would be high resistance possibly due to a break in a wire. The circuit will not have current flowing through it and behave as if it were off. 2. a. The result of a short to ground would be high current flow due to the low resistance. 3. d. An ammeter is connected in series to a circuit with the circuit turned on. The ammeter measures the amperage passing through the meter. 4. a. An ohmmeter is connected in parallel with the circuit with the circuit turned off. 5. d. A zero reading on an ohmmeter could indicate a short to ground. It could also indicate that the circuit has no resistance or there is a short in a component that should have a specific resistance. 6. c. A good-quality multimeter would have an internal resistance of 10 mega ohms (10 million ohms). 7. b. An upward movement of the trace indicates an increase in voltage. 8. c. The fuse used in a circuit should be 120 percent of the circuit current. 9. d. When connecting wires or installing connectors, rosin-core solder should be used. 10. c. A high voltage drop would indicate a poor connection in a circuit. 11. d. No continuity between the battery terminal and the output terminal of a relay would indicate a defective relay. To check for continuity through a relay, power the relay coil only while checking continuity across the battery and output terminals. 12. a. 10 Mega ohms is the largest resistance listed. 13. d. To correctly measure a volt drop, the voltmeter must be connected in series with the test area with the power on. 14. a. A digital storage oscilloscope (DSO) displays voltage and time. 15. a. A trigger tells the scope when to start displaying the wave form. Setting the trigger is important when trying to observe the timing of an input or output circuit device. 16. c. The slope on digital storage oscilloscope (DSO) refers to a rising or falling signal. The slope switch will determine whether the trace will begin on a rising or falling of the signal. 17. b. With a DVOM connected between the engine block and the negative battery post, any measured voltage would indicate a ground circuit resistance. The 1 volt reading would indicate a voltage drop in the connections or wiring between the two DVOM leads. 18. c. A resistance in the ground circuit of a taillight would most likely prevent the lamp from illuminating. This resistance would show up as a voltage drop. 19. a. When electrical accessories are added to a car, the wire size must increase to safely handle the added current. 20. b. A DVOM connected between the ground side of a lighting circuit and the negative battery post should read close to zero volts. Any measured voltage would be a voltage drop that would indicate resistance in the ground circuit.

3-15

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 18 Batteries: Theory, Diagnosis, and Service CHAPTER OVERVIEW Different types of batteries are described in this chapter. Cleaning, servicing, and charging procedures are explained.

LEARNING OUTCOMES

• • • • • • • • • • •

Describe how a battery works. List the precautions that must be adhered to when working with or around batteries. Describe the basic construction of an electrochemical cell. Explain how electrochemical cells can be connected to increase voltage and current. Explain the different methods used to recharge a battery. List and describe the various ways a battery may be rated. List and describe the various types of batteries according to their chemistries that may be used in automobiles. List the precautions that must be adhered to when working with or around high-voltage systems. Describe the construction and operation of a lead-acid battery. Describe the various types of lead-acid batteries that are available today. Describe the basic services and testing procedures for a lead-acid battery.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Introduction II. Basic Battery Theory A. Basic Construction B. Charging C. Cell Arrangements 1. Series Connections 2. Parallel Connections 3. Series-Parallel Connections D. Battery Hardware 1. Battery Cables

3-16

Automotive Technology: A Systems Approach, 3Ce 2. Battery Hold-downs 3. Heat Shields E. Recycling Batteries III. Battery Ratings A. Ampere-Hour B. Watt-Hour Rating C. Cold Cranking Amps D. Cranking Amps E. Reserve Capacity IV. Common Types of Batteries A. Battery Chemistry 1. Lead-Acid 2. Nickel-Cadmium (NiCad) 3. Nickel-Metal Hydride (NiMH) 4. Sodium-Sulphur (NaS) 5. Sodium-Nickel-Chloride 6. Lithium-Ion (Li-Ion) 7. Lithium-Polymer (Li-Poly) 8. Nickel-Zinc V. Lead-Acid Batteries A. Basic Construction 1. Casing Design 2. Terminals B. Discharging and Charging C. Designs 1. Maintenance-Free and Low-Maintenance Batteries 2. Hybrid Batteries 3. Recombination Batteries 4. Absorbed Glass Mat Batteries 5. Valve-Regulated Batteries D. Factors Affecting Battery Life 1. Improper Electrolyte Levels 2. Temperature 3. Corrosion 4. Overcharging 5. Undercharging/Sulphation 6. Poor Mounting 7. Cycling VI. Servicing and Testing Batteries A. Inspection B. Battery Leakage Test C. Cleaning the Battery and Terminals D. Battery Hydrometer E. Built-in Hydrometers F. Open Circuit Voltage Test G. Battery Load Test 1. Interpreting Results H. Battery Capacitance Test I. Battery Drains J. Battery Cables K. Battery Chargers

3-17

Automotive Technology: A Systems Approach, 3Ce L. Replacing a Battery Hint: If possible, obtain a battery that has exploded to use as an object lesson. Show the students the consequences of careless battery service. Show how the cells are constructed and connected to each other. VII. Jump-Starting

ADDITIONAL TEACHING HINTS

• • • • • •

Demonstrate a visual inspection of a battery. Demonstrate a hydrometer test for specific gravity in a maintenance type battery. Demonstrate an open circuit voltage test. Demonstrate a capacity (load) test with a VAT. Demonstrate proper slow and fast charging of a battery. Demonstrate proper jump-start procedures with battery cables and a booster battery (or between vehicles).

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

A common stumbling block regarding batteries will be how the electricity is made by chemical reaction. If students are having a difficult time with this concept go back to high school science class theory and use a citric fruit to create a small electrical signal. This will demonstrate the same principles as our automotive battery. Also use the information on page 537of Chapter 18 to reinforce the concept. To help the students realize that the battery is just another energy source have them create a list with as many different energy sources as possible.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Look at the batteries on five different vehicles. Describe the type of battery and record the ratings listed on the battery in each vehicle. Include in your description the rating of the battery and terminal position. 2. Look at the batteries on five different vehicles. Describe where the positive and negative battery cables are connected to the vehicle in each case. Making a drawing of these connections would be helpful. 3. On five different late-model vehicles, use a DMM and appropriate test leads to measure the parasitic load on the batteries. If the load is high according to the manufacturer, determine the cause and describe what you did to find the cause. CASE STUDY 4. The customer complains that his battery is “dead” every morning. List the possible causes of the problem and what can be done to find the cause of the problem.

3-18

Automotive Technology: A Systems Approach, 3Ce

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. c. The voltage reading of a fully charged, 12V, automotive lead-acid battery would be 12.6 volts. Each of the six cells of a lead-acid battery should produce 2.1 volts when fully charged. 2. c. If a lead-acid battery had one shorted cell the voltage reading from the battery should be 10.5 volts. 12.6 – 2.1 = 10.5 volts. 3. b. The minimum voltage required to perform a battery load or capacity test would be 12.4 volts. This voltage indicates that the battery has a state of charge of approximately 75 percent. 4. d. During a battery load test (performed at 20°C [70°F]) the battery voltage should not drop below a minimum of 9.6 volts. 5. b. The electrolyte of a lead-acid battery is a solution of water and sulphuric acid. The mixture of a fully charged battery reading 12.6 volts is 65 percent water and 35 percent sulphuric acid. 6. c. A hydrometer is the preferred testing tool of a battery with removable vent covers. This tool measures the electrolyte mixture strength or state of charge by reading its specific gravity. 7. c. Lead peroxide is used in the positive plates of a lead-acid battery. 8. c. The separators separate the positive and negative plates in the battery. Any contact between plates would allow them to lose their stored energy. 9. a. The specific gravity of the electrolyte of a fully charged lead-acid battery at 27.6°C (80°F) would be 1.260–1.280. 10. a. Compensation for specific gravity reading is required for changes in temperature. The density of most liquids is affected by temperature. 11. d. Specific gravity refers to the weight of the acid/water mix. 12. a. The “eye” or battery indicator indicates the state of charge of a sealed battery. 13. d. Parasitic draw or battery drain is measured with an ammeter in series between the battery negative post and the negative cable. 14. d. The maximum parasitic draw on a battery is 0.025 to 0.050 amps. 15. a. CCA (cold cranking amps) refers to the battery’s ability to deliver current for 30 seconds at −17.8°C (0°F). 16. c. Reserve capacity refers to the battery’s ability to delivery 25 amps while maintaining a minimum of 1.75 volts per cell. 17. b. A battery leakage test is performed by placing a voltmeter’s positive lead on the battery positive post and the negative lead on the battery case. This test can also be performed with the negative lead on the negative post and positive on the battery case. 18. a. Another name for an AGM (absorbed glass mat) battery is a spiral cell battery. 19. c. A deep cycle battery can be continually discharged and recharged. This is accomplished by its grid material and construction. 20. a. A discharged battery may freeze in cold weather due to the electrolytes reduction to mostly water.

3-19

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 19 Starting Systems CHAPTER OVERVIEW This chapter describes the starting system and explains its service and repair.

LEARNING OUTCOMES

• • • • • • • •

Explain the purpose of the starting system. List the components of the starting system, starter circuit, and control circuit. Explain the different types of magnetic switches and starter drive mechanisms. Explain how a starter motor operates. Describe the operation of the different types of starter motors. Perform basic tests to determine the problem areas in a starting system. Perform and accurately interpret the results of a current draw test. Disassemble, clean, inspect, repair, and reassemble a starter motor.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Starting System—Design and Components A. Starter Circuit 1. Battery and Cables 2. Magnetic Switches 3. Starter Motor 4. Starter Motor Drive Mechanisms 5. Permanent Magnet Starter Motors 6. Starter Drive 7. Overrunning Clutch II. Control Circuit A. Starting Safety Switch III. Starting System Testing A. Preliminary Checks B. Safety Precautions C. Troubleshooting Procedures D. Starter Solenoid Problems E. Starting Safety Switches F. Battery Load Test G. Cranking Voltage Test

3-20

Automotive Technology: A Systems Approach, 3Ce 1. Test Conclusions H. Cranking Current Test I. Insulated Circuit Resistance Test 1. Test Conclusions J. Ground Circuit Resistance Test 1. Test Conclusions K. Voltage Drop Test of the Control Circuit 1. Test Conclusions L. Test Starter Drive Components 1. Test Conclusions M. Removing the Starter Motor N. Free Speed (No-Load) Test IV. Starter Motor Service A. Starter Motor Component Tests 1. Field Coil Tests 2. Armature Tests 3. Brush Inspection 4. Bearings and Bushings 5. Starter Drives and Clutches B. Starter Motor Reassembly

ADDITIONAL TEACHING HINTS

• • •

Demonstrate the basic tests for determining problem areas in a starting system. Demonstrate and accurately interpret the results of a current draw test.

Demonstrate and accurately interpret the results of voltage drop tests on the insulated and ground circuits.

• •

Demonstrate starter bench tests and interpret the results. Disassemble, clean, inspect, repair, and reassemble a starter motor.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

The starter system and more specifically the starter motor is the largest single electrical draw on the vehicle and it is done with magnetism. This may be a stumbling block for the students, understanding how magnetism can accomplish such a feat. Use chapter information, beginning on page 563 of Chapter 19 to reinforce the theory. Ensure the students understand the mechanical advantage (through the use of two very different size gears) that the starter motor uses to crank the engine.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Gather three different-sized starter motor armatures. Place them in the growler, one at a time, and go through the test sequence for testing an armature for opens and shorts. An armature can be tested with an ohmmeter without a growler. Clean the commutator with crocus cloth. Then place the ohmmeter on its lowest scale. Connect the test leads to any two commutator ©2016 Nelson Education Ltd.

3-21

Automotive Technology: A Systems Approach, 3Ce segments. There should be zero resistance. If a resistance is measured, the armature needs to be replaced. Set the ohmmeter to the 2K scale and connect one of the meter leads to the armature shaft and the other to a segment on the commutator. Check each segment. The ohmmeter should read infinite. If any resistance is measured, the armature windings are shorted and the armature should be replaced.

CASE STUDY 2. A customer brings her car into the shop with a dead battery and says that every time the car gets hot and she shuts it off, she needs a jump to get it going again. The technician tests the battery and finds that it is normal. What other possibilities should be checked?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. b. If 200 amps of current is flowing in the positive or insulated side of the starter circuit, the same current (200 amps) must also flow in the ground side. Current flow is constant through a series circuit. 2. b. A voltage drop test is performed with a voltmeter and is the preferred test to locate starter circuit resistance. This test will read resistance in connections, wiring, and components because it is performed with the circuit intact. 3. b. Slower cranking speed and higher current flow than specified during a starter motor test could be caused by a mechanical binding or resistance in the engine. The greater the cranking demand placed on the starter will increase the amount of current required. 4. c. A permanent magnet gear reduction starter generally has greater torque output. A ballast resistor is sometimes used in ignition circuits. 5. d. The hold-in winding is activated when the starter is cranking. The hold-in winding directs battery voltage to the starter field coils and armature for cranking. 6. a. The armature is the rotating component of the starter motor. 7. c. The gear ratio between the starter drive pinion and the engines ring gear is approximately 20 to 1. This gear reduction enables the starter motor to crank an engine with relative ease because the starter’s torque is multiplied by 20. 8. c. An engine that requires 2000 watts to crank will force the starter to draw 200 amps if the voltage dropped to 10 volts during cranking. 200 amps × 10 volts = 2000 watts. 9. d. A series wound starter will produce the highest torque at low speed. 10. a. A solenoid changes electrical energy into mechanical energy. The starter motor solenoid produces the force required to push the starter motor drive pinion into mesh with the engines ring gear. 11. a. An open hold-in winding would allow the pull-in winding to cycle the plunger in and out the solenoid (chatter). This would allow the plunger contact disc to only momentarily touch the motor feed terminal producing only slight staggered rotation of the starter motor and not enough cranking to start the engine. 12. d. The allowable voltage drop in the insulated side of the starter circuit is 0.3 volts. 13. b. A high resistance would be indicated by high voltage drops in the starter system circuit. 14. c. 9.6 volts is considered to be the minimum acceptable voltage available to the starter motor during a cranking voltage test. 15. b. When the ignition switch is turned to the start position, the first event to occur is the energization of the pull-in winding. The pull-in winding draws the plunger into the solenoid which pushes the drive pinion into mesh with the engines ring gear. 16. c. A low charge in the battery would cause low current flow through the starter and slower than specified cranking rpm. ©2016 Nelson Education Ltd.

3-22

Automotive Technology: A Systems Approach, 3Ce 17. c. The use of high viscosity oil in the engine crankcase will increase the engines resistance to turn therefore resulting in slower than specified cranking. 18. b. A whine while the engine is cranking could be caused by too much clearance between the starter drive pinion and the engines ring gear. The improper clearance will produce improper tooth contact. 19. a. A whine after the engine starts could be caused by too little clearance between the starter drive pinion and the engines ring gear. The improper clearance could prevent the drive pinion from disengaging the ring gear or allow the drive pinion to rub against the back side of the ring gear teeth. 20. b. The CEMF (counter electromotive force) limits the maximum current flow drawn from the battery during cranking. CEMF is a voltage induced in the armature during starter operation that opposes battery voltage reducing the current flow through the armature.

3-23

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 20 Charging Systems CHAPTER OVERVIEW This chapter describes the design of and the components included in the charging system. Testing the charging system is explained, with emphasis on AC generators.

LEARNING OUTCOMES • Explain the purpose of the charging system. • Identify the major components of the charging system. • Explain the purposes of the major parts of an AC generator. • Explain half- and full-wave rectification and how they relate to AC generator operation. • Identify the different types of AC voltage regulators. • Describe the two types of stator windings. • Explain the features enabled by the use of a starter/generator unit. • Perform charging system inspection and testing procedures using electrical test equipment.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Alternating Current Charging Systems A. AC Generator Construction 1. Rotor 2. Slip Rings and Brushes 3. Stator 4. End Frame Assembly 5. Cooling Fans 6. Liquid-Cooled Generators II. AC Generator Operation A. DC Rectification B. Voltage Regulation C. Field Circuits D. Electronic Regulators 1. Fail-Safe Circuits E. Computer Regulation F. Indicators 1. Indicator Light 2. Meters III. New Developments A. 42-Volt Generators B. Starter/Generators C. Other Applications

3-24

Automotive Technology: A Systems Approach, 3Ce

IV. Preliminary Checks A. Safety Precautions B. Inspection C. Alternator Pulley Technologies 1. Background 2. Type I–OAP (INA) 3. Type II–OAD (Litens) V. General Testing Procedures A. Voltage Output Test B. Current Output Test C. Field Current Check D. Diode Checks E. Oscilloscope Checks F. Circuit and Ground Resistance VI. AC Generator Service

ADDITIONAL TEACHING HINTS

• • • •

Perform charging system inspection and testing procedures using electrical test equipment. Disassemble an early-model AC generator and test all of the individual components. Disassemble a late-model AC generator and compare its components with the previous model. Demonstrate how a loose belt can affect AC generator output.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Ensuring that the students understand the concept of magnetism and how it relates to creating electricity is essential for the understanding of a charging system and specifically the AC generator. The basic explanation on page 586 of Chapter 20 will help but using visual aids will reinforce the concept. Energizing the rotor from an AC generator and using metal filings from a brake lathe to show magnetic flux lines that are created may help with this concept.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On a vehicle assigned to you, or by referring to service information, determine the output rating of the AC generator using the numbers stamped into or cast onto the generator housing. 2. Using service information, locate the two different types of clutching pulleys used. Record the test procedures used to test the systems and if possible, using a test vehicle equipped with the technology, perform the test procedure.

3-25

Automotive Technology: A Systems Approach, 3Ce CASE STUDIES 3. The battery on a customer’s car seems always to overcharge. The battery seems very hot after operation, and the customer has replaced the battery once. What could be the problem? 4. The customer complains that the alternator light is on constantly when the engine is running. What could be the problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. b. The diode trio provides current flow to the field. It does this by rectifying AC voltage that has been produced in the stator into DC so that it can be used to create the magnetic field in the field coil of the rotor. 2. a. The three factors that determine the amount of induced voltage is the speed in which the magnetic field is cut, the number of conductors, and the strength of the magnet or magnetic field. 3. b. Diodes are used to change AC to DC by only allowing current flow in one direction. Two diodes are used for each stator winding. 4. a. In an AC generator, output voltage is produced in the stator. 5. a. The voltage regulator regulates the voltage output of an AC generator by controlling the amount of current through the field, which changes the strength of the magnetic field. 6. a. The acceptable AC voltage measured between a ground and the generators battery terminal would be below 0.5 volt. This would indicate proper diode operation. 7. c. Engine should be maintained at approximately 2000 rpm during a battery load test to determine AC generator output. 8. a. In a type-A field circuit the ground is placed in the ground side of the field circuits. 9. a. A delta wound stator can generate the maximum current output from an AC generator. 10. d. Full-wave rectification will convert AC voltage to DC voltage. This requires one diode on the negative side and one diode on the positive side of each stator winding. 11. c. The most likely cause of an overcharged battery would be a defective voltage regulator. All of the other choices would result in lower AC generator output. 12. a. The purpose of the brushes in an AC generator is to carry current to the field coils in the rotor. 13. d. The zener diode is the major voltage control device in the voltage regulator. 14. c. By offsetting the three stator windings three-phase alternating current is produced. 15. a. The brushes in the AC generator housing connect with the slip rings on the rotor to transfer current to the field coil of the rotating rotor. 16. c. The voltage output from the AC generator will rise as the temperature decreases. This will force the battery which is more reluctant to accept a charge at low temperatures to accept it and become fully charged. 17. d. The duty cycle of the field current during a high-current-demand situation would be approximately 80 percent. 18. a. The current through the rotor will determine the amperage output of the AC generator. The amount of current through the field will increase or decrease the strength of the magnetic field and the amount of voltage induced in the stator windings. 19. b. The maximum allowable voltage drop reading on the insulated or feed circuit of an AC generator is 0.5 volt. A higher reading would indicate a high resistance problem in the circuit. 20. a. The zener diode allows the voltage regulator to sense voltage. ©2016 Nelson Education Ltd.

3-26

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 21 Lighting Systems CHAPTER OVERVIEW Lighting systems provide both safety and convenience to the motorist. Understanding how these circuits operate is essential to being able to maintain them. This chapter introduces the use of schematic diagrams to aid in diagnosis and service.

LEARNING OUTCOMES • • • • • • • • •

Explain the operating principles of the various lighting systems. Describe the different types of headlights and how they are controlled. Understand the functions of turn, stop, and hazard warning lights. Know how backup lights operate. Replace headlights and other burned-out bulbs. Explain how to aim headlights. Explain the purpose of auxiliary automotive lighting. Describe the operation and construction of the various automotive lamps. Diagnose lighting problems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Automotive Lamps A. Incandescent Lamps B. Halogen Lamps C. Neon Lamps D. Fluorescent Lamps E. High-Intensity Discharge Lamps F. Light-Emitting Diodes (LED) II. Headlights A. Sealed-Beam Headlights B. Halogen Headlamps 1. Composite Headlights C. High-Intensity Discharge (HID) Headlamps 1. Bi-Xenon Lights 2. Cylindrical Housings D. LED Headlights E. Daytime Running Lights 1. LED DRL Systems F. Concealed Headlights G. Auxiliary Lights 1. Headlight Switches H. Dimmer Switches

3-27

Automotive Technology: A Systems Approach, 3Ce I. Headlight Circuits J. Flash to Pass III. Automatic Light Systems A. Automatic Headlamps 1. High-Beam Detection 2. Delay Systems B. Adaptive High-Beam Assist C. Glare-Free High Beams D. Adaptive Headlights E. Headlamp Levelling Systems IV. Headlight Service A. Restoring Headlight Lenses 1. Lens Cleaners V. Headlight Replacement A. Sealed-Beam Headlight Replacement B. HID Diagnosis and Service 1. Normal Delay 2. Bulb Colour 3. Bulb Replacement C. Adaptive High-Beam Assist D. Headlight Adjustments E. Auto-Levelling Headlamps 1. Diagnosis F. Automatic Headlight System Diagnosis G. Adaptive Headlight Diagnosis VI. Interior Light Assemblies 1. Engine Compartment Light 2. Glove Box Light 3. Luggage Compartment Light 4. Trunk Lid Light 5. Vanity Light 6. Courtesy Lights 7. Illuminated Entry System A. Distributed Lighting System VII. Rear Exterior Light Assemblies A. Turn, Stop, and Hazard Warning Light Systems 1. Flashers B. Brake Lights C. LED Lights 1. Adaptive Brake Lights 2. Backup Lights VIII. Light Bulbs A. Other Bulbs 1. Fog Lights IX. Lighting Maintenance

3-28

Automotive Technology: A Systems Approach, 3Ce

ADDITIONAL TEACHING HINTS

• • •

Demonstrate headlight adjustments required by provincial and/or federal laws. Have students remove all the bulbs on a shop car and catalogue them. Demonstrate how to troubleshoot a lighting system using an electrical schematic.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

This is a good area to have the students practise their wiring diagram reading. Have the students use the chapter information and relate it to a few vehicle lighting systems. Have them locate the components involved in lighting based on the layout of the wiring diagram. It is difficult at times to diagnose lighting faults because of the layout in the vehicle and tying the front and rear lights together. Have the students disconnect a ground connection at a light assembly and have them explain the result.

3-29

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. To solve lighting system problems effectively, you must know how to read an electrical schematic. In a typical headlight schematic (Figure 21–1), trace the current through the various components of the circuit.

2. A customer complains that his cigarette lighter does not pop out or get hot. However, if he pushes in the cigarette lighter, the dome light comes on dimly. Using Figure 21–2, determine the cause.

CASE STUDY

3-30

Automotive Technology: A Systems Approach, 3Ce 3. A customer brings in her vehicle and complains that the right headlight is quite a bit dimmer than the left headlight. Outline the steps that should be taken to identify the exact cause of the problem.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. c. It takes 200 ms for a tungsten filament bulb to reach full brightness. 2. c. A feature of composite headlights used on most modern cars is the use of removable bulbs. 3. b. Xenon gas is commonly used in HID headlights. 4. d. 15 000 volts are required to initially start an HID headlight. 5. b. HID headlights appear blue in colour to produce light closest to natural light. 6. c. The most likely reason for interior lights to not operate when a door is opened would be a door switch stuck in the closed position. The lights would still illuminate with the interior light switch because they are parallel circuits. 7. c. A circuit breaker will allow the headlights to continue to operate, even after a temporary short circuit. 8. d. An LED requires only 1 ms to illuminate after it is energized. 9. c. The low current consumption of LED lights make them popular on today’s vehicles. 10. b. Fog lights, because of their light pattern, must be located below the bumper and away from the vehicle centreline. 11. c. Fog lights are limited to being only on with the low beams. 12. a. The daytime running lights that are mandatory on all new Canadian automobiles are commonly controlled by applying reduced voltage to the headlamps. 13. b. The flash to pass feature allows the headlights to illuminate even with the headlight switch off or on the low-beam setting. 14. c. A bi-metal switch is used in a simple turn signal flasher. 15. c. Filling the fuel tank is not one of the recommended steps prior to aiming the headlights. 16. b. HID type headlights are constantly electronically adjusted for changing road and ride height conditions on some vehicles. 17. c. Relays are added to auxiliary lighting circuits to protect the switch and wiring. 18. d. An open on the ground side would produce a battery voltage reading on both the feed and the ground side of a light assembly. 19. a. A photo diode is used to activate the dimming circuit of automatic dimming headlights. 20. b. When replacing halogen-style headlight bulbs, it is important to not touch the glass part of the bulb.

3-31

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 22 Instrumentation and Information Displays CHAPTER OVERVIEW This chapter introduces the various gauges and warning devices found in the instrument cluster.

LEARNING OUTCOMES

• • • • • •

Describe the two types of instrument panel displays. Know the purpose of the various gauges used in today’s vehicles and how they function. Describe the operation of the common types of gauges found in an instrument cluster. List and explain the function of the various indicators found on today’s vehicles. List and explain the function of the various warning devices found on today’s vehicles. Explain the basics for diagnosing a gauge or warning circuit.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Instrument Panels A. Displays 1. Vacuum Fluorescent B. Heads-Up Display 1. Light-Emitting Diodes (LEDs) 2. Liquid-Crystal Displays (LCDs) 3. Cadillac CUE 4. Ford’s SmartGauge II. Gauges A. Air Core Gauge B. Quartz Analog Gauge C. Magnetic Gauges D. Thermal or Bimetallic Gauge E. Diagnosis Hint: Remove the cover so that the working parts of various types of gauges may be observed. Explain the operating principles of each type. III. Electronic Instrument Clusters A. Prove-Out Display IV. Basic Information Gauges

3-32

Automotive Technology: A Systems Approach, 3Ce A. General Diagnosis and Testing B. Speedometer C. Odometer 1. Trip Odometer 2. Diagnosis D. Oil Pressure Gauge 1. Diagnosis E. Coolant Temperature Gauge 1. Diagnosis F. Fuel Level Gauge G. Tachometer H. Charging Gauges V. Indicators and Warning Devices A. Light Indicators and Warnings B. Diagnosis C. Engine-Related Warning and Indicator Lights 1. Check Engine Light 2. Oil Pressure Light 3. Charge Indicator Light 4. Check Filler Cap 5. Add Coolant Lamp D. Electronic Throttle Control Light E. Safety-Related Warning and Indicator Lights 1. SRS Air Bag Readiness Light F. Passenger or Side Air Bag Off Light 1. Fasten Belts Indicator 2. Brake Warning Light 3. Brake Pad Indicator 4. Parking Brake Warning Light 5. Brake Fluid Level Warning Light 6. Lamp-Out Warning Light 7. Stoplight Warning Light 8. Antilock Light VI. Driver Information Warning and Indicator Lights A. Blind Spot Detection, Backup, and Lane Departure Warnings 1. Low-Fuel Warning 2. Maintenance Reminder 3. Transmission Indicator 4. Drive Indicator 5. O/D Off Indicator 6. Rear Defrost Indicator 7. High-Beam Indicator 8. Left and Right Turn Indicators 9. Fog Light Indicator 10. Tire Pressure Monitor (TPM) 11. Traction/Stability Control Lamp 12. Cruise Control Light 13. Air Suspension Light 14. Door Ajar Warning 15. Add Washer Fluid 16. Fuel Consumption Gauge

3-33

Automotive Technology: A Systems Approach, 3Ce B. Sound Warning Devices 1. Park Distance Control (PDC) VII. Driver Information Centres A. Graphic Displays B. Hybrid Vehicles 1. Honda 2. Toyota

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

A stumbling block for most beginning technicians will be the fact that there is an overwhelming number of indicators and warning lights for the driver to take in. Group the types of warning indicators and information lights, use information from throughout the chapter and have the students each take a vehicle, list the indicators, and then compare lists.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. While electrical instrument and accessory circuits may need special test equipment and special procedures, most troubleshooting problems can be solved with a jumper wire, voltmeter, ohmmeter, test lamp, and self-powered test lamp. The latter is a bulb, battery, and set of test leads wired in series. When connected to two points of a continuous circuit, the bulb glows. Using a service information system, identify three circuits that switch the power for circuit operation and identify two circuits that switch the ground for circuit operation. CAUTION: When using a self-powered test lamp or ohmmeter, be sure power is off in the circuit during testing. Live circuits can cause equipment damage and false readings.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. b. An analog display shows changes in readings better than a digital display. The sweeping motion of a needle will indicate a rise or fall of engine speed better than a digital read-out. 2. d. A piezoresistive sensor is usually used to monitor engine oil pressure. Oil pressure against a flexible diaphragm moves a contact arm along a resistor. The position of the contact arm determines the resistance value and the current flow through the gauge. 3. a. A digital display will display information more accurately. 4. a. A temperature sensor is typically a variable resistor which results in varying DC voltage sent to electronic components and varying current sent to gauges. 5. c. When in reverse, buzzers or chimes are the most common type of distance warning devices for the driver. 6. a. A poor instrument-panel ground would be the likely cause of all gauges reading lower than expected. The added resistance would reduce the current flow through the gauges. 7. b. Accumulated mileage is stored in non-volatile ROM so that the mileage value is retained even when the battery is disconnected. 8. c. The fuel gauge would read empty if the wire from the fuel gauge to the sending unit was grounded. Low resistance results in low gauge readings and high resistance results in higher gauge readings.

3-34

Automotive Technology: A Systems Approach, 3Ce 9. c. When discussing instrumentation, HUD stands for heads-up display. 10. c. Bobbin gauges are the most commonly used analog gauge used for displaying pressure, temperature, and fuel level. 11. a. The park distance control (PDC) feature uses ultrasonic sensors to measure vehicle distance in relation to an object. 12. c. Indicator and warning lights are usually triggered by switches. Indicator lights inform the driver that something has been turned on while warning lights warn the driver of a malfunction. 13. c. An indicator light flashing faster than usual will generally alert the driver to a problem in the turn signal lights. 14. a. The needle of a balanced coil gauge will rest at the lowest end of the scale when the power is shut off. 15. c. The first step in diagnosing any system problem is to verify the complaint. This should be followed by a good visual inspection of the circuit. These two steps should precede all other service procedures. 16. c. The indicator needle of a cable-driven speedometer is held in the zero position by a hairspring. 17. b. A HUD (heads-up display) projects an image by the use of a liquid crystal display (LCD). 18. d. Warning lamps are usually light-emitting diodes (LED). These are used because of their reliability, low current operation, and low temperature operation. 19. c. When testing a temperature sensor, resistance and voltage is usually checked. The sensor resistance is measured and compared to specifications and the voltage to the sensor is confirmed. 20. c. The MIL (malfunction indicator light) stays illuminated to notify the driver that there is a computer-monitored problem. The light will stay on as long as the engine is running when there is a fault in the system or when the computer has stored a fault or diagnostic code in its memory.

3-35

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 23 Electrical Accessories CHAPTER OVERVIEW This chapter describes the different accessories such as power door locks, keyless entry systems, power windows, power seats, security systems, and other basic systems such as the windshield wipers/washers and defrosters. In order to understand these systems it is also necessary to be familiar with self-diagnostic computer controlled systems such as body control modules.

LEARNING OUTCOMES

• • • • • • • •

Explain the basic operation of electric windshield wiper and washer systems. Explain the operation of power door locks, power windows, and power seats. Understand how cruise control operates and the differences in the various systems. Know how to diagnose blower motor problems. Determine how well the defroster system performs. Identify the components of typical audio and video systems. Diagnose problems with power door and window systems. Understand the operation of the various security systems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Body Control Modules A. Trouble Codes B. Entering Diagnostics Hint: Display printouts of several diagnostic trouble codes (DTCs) and discuss possible causes. II. Windshield Wiper/Washer Systems A. Permanent Magnet Motor Circuits 1. Park Switch 2. Depressed Park Wiper Systems B. Electromagnetic Field Motor Circuits 1. Three-Speed Motors 2. Windshield Wiper Linkage and Blades 3. Rear-Window Wiper/Washer System C. Intermittent Wiper Systems 1. Rain-Sensing Wipers

3-36

Automotive Technology: A Systems Approach, 3Ce 2. Speed-Sensitive Wipers D. Windshield Washers E. Wiper System Service F. Washer System Service III. Horns/Clocks/Power Outlet Systems A. Horns 1. Horn Diagnosis B. Clock C. Power Outlet IV. Blower Motors A. Diagnosis V. Cruise (Speed) Control Systems A. Electronic Cruise Control Systems B. Adaptive Cruise Control C. Cruise Control System Service VI. Sound Systems A. Antenna 1. Power Antennas B. Satellite Radio C. Speakers D. CD Players E. DVD Systems 1. Self-Diagnostics F. Amplifiers G. Diagnosis 1. Satellite Radio Reception Factors VII. Telematics A. Phone Systems 1. Bluetooth B. Voice activation System VIII. Navigation Systems A. Vehicle Tracking Systems IX. Power Lock Systems 1. Automatic Door Locks A. Child Safety Locks B. Power Trunk Release C. Diagnosis X. Power Windows A. Window Lockout Systems B. Circuit Operation 1. Express Windows 2. Obstacle-Sensing Windows C. Diagnosis 1. Guidlines XI. Power Seats A. Climate Control Seats B. Other Seat Options 1. Power Lumbar Supports 2. Memory Seats 3. Adaptive and Active Seating 4. Massaging Seats

3-37

Automotive Technology: A Systems Approach, 3Ce C. Diagnosis XII. Power Mirror System 1. Electrochromic Mirrors A. Inside Mirrors B. Power Folding Mirrors XIII. Rear-Window Defroster and Heated Mirror Systems A. Diagnosis XIV. Other Electronic Equipment A. Adjustable Pedals B. Heated Windshields C. Power Roof Systems 1. Solar Sunroof D. Retractable Hardtops E. Forward and Reverse Sensing Systems F. Rearview Cameras 1. Nighttime and Dark Areas G. Parking Assist H. Bling Spot Detection I. Lane-Departure Warning Systems J. Pre-Collision Systems K. Self-Parking L. Night Vision XV. Garage Door Opener System XVI. Security and Antitheft Devices A. Locks and Keys B. Passkeys C. Smart Keys D. Keyless Entry Systems 1. Automatic Liftgate Openers E. Alarm Systems 1. Diagnosis

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

One stumbling block for even journeypersons in the automotive trade is to keep up with advancements from all of the manufacturers. Have the students pick one of the electrical options on a vehicle of their choice and have each of them explain its operation and features to the rest of the class. Ensure that the students have the ability to search the options for a particular vehicle. Have them find the options list on the vehicle and work towards deciphering it.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. List five safety-related systems and 10 convenience accessory systems found in this year’s vehicles.

3-38

Automotive Technology: A Systems Approach, 3Ce 2. Select a vehicle equipped with smart key technology and record all of the components involved in starting the vehicle, include a wiring diagram of the system. If a smart key-equipped vehicle isn’t available, use service information to record all of the components involved in activating the smart key starting system. CASE STUDY 3. An electric windshield wiper system can cause a technician plenty of headaches. The wiper may not shut off, it may be sluggish as it moves, or the washer system may not operate. But the most common problem is an inoperative wiper. One of the easiest procedures for solving an inoperative wiper problem is to use a diagnostic tree. While this is an example of a troubleshooting procedure for a specific manufacturer, most service information systems use trees in their diagnostic information. (1) How many problems can you find in the tree that would cause the wiper to be inoperative? (2) Summarize the logical flow of the diagnostic tree.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. c. Multiple speeds are obtained from an electromagnetic field wiper motor by varying the current through the shunt field. Decreasing current through the shunt field decreases its magnetic field allowing the series field to turn the armature at a higher speed. With equal current flow through both the series and the shunt fields, the opposing magnetic field result in slow motor operation. 2. a. When testing power door locks reveals that none of the door locks work in any door and the fuse tests okay, the power feed circuit to the door lock actuator should be tested. The power circuit is routed to the doors and can be damaged (opened) during door opening and closing. 3. a. A binding of the seat movement mechanism is a likely cause of a tripped power seat circuit breaker whenever the adjuster switch is moved forward or rearward. The binding will place an undue load on the seat motor causing it to draw more current. 4. c. The letters GPS stand for “Global Positioning System.” 5. b. The front vertical motor raises and lowers the front of a six-way seat. 6. a. When testing an external antenna for poor reception or a defect with an ohmmeter, there should be no continuity between the mast and ground. 7. a. A power trunk release uses a solenoid to open the latch. When the switch is pressed, voltage is applied through the switch to the solenoid. 8. d. With no power window motor switches operated, both motor leads are isolated from the rest of the circuit. The switches provide the power and the ground to the power window motors when they are pressed so the direction of current flow through the motor can be reversed. The direction of current flow will determine the direction of motor rotation. 9. d. An internal circuit breaker protects the power window motor. If the switch is held after the motor has reached its lowest or highest position or if the window is obstructed the circuit breaker will open the circuit. 10. b. The lumbar support in a seat supports the lower lumbar region of the back (spinal column). The support allows the driver to inflate or deflate a bladder located in the lower seat back. 11. c. Memory seats have the ability to store the driving position of several drivers. 12. c. When a heated windshield system is operating, the voltage at the windshield can reach 90 volts. The generator’s output is redirected from the normal electrical system to the windshield. When the voltage regulator senses a drop in battery voltage, it full fields the generator so it can put out between 30 and 90 volts. ©2016 Nelson Education Ltd.

3-39

Automotive Technology: A Systems Approach, 3Ce 13. c. Passive alarm systems are considered more effective because they are switched on automatically when the ignition key is removed or the doors are locked. 14. d. Ultrasonic sensors are used in more sophisticated alarm systems to detect movement inside the vehicle. 15. a. Keys equipped with a transponder receive and send radio signals to and from the PCM. If the transponder is unable to return the same signal it receives, the engine will not start. 16. a. The FM (frequency modulated) radio band offers the best sound quality. 17. d. Adaptive cruise control systems have the ability to slow down and speed up to maintain a safe distance with the vehicle in front. The system uses laser or radar sensors to determine the distance from the preceding vehicle. 18. a. An audio system with the automatic sound level feature relies on vehicle speed to determine the amount of volume change required. 19. b. Before disconnecting or changing a battery, the radio security code must be known if the vehicle is equipped with an antitheft audio system. 20. c. The advanced night vision (thermal imaging) image is displayed by the heads-up display (HUD).

3-40

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 24 Restraint Systems: Theory, Diagnosis, and Service CHAPTER OVERVIEW Safety is a primary consideration not only in the design of automobiles, but also in the purchase decision made by consumers. Many safety features are available either as standard equipment or as options. This chapter describes restraint systems and how to diagnose and service them.

LEARNING OUTCOMES

• • • • • • •

Identify and describe devices that contribute to automotive safety. Explain the difference between active and passive restraint systems. Know how to service and repair passive belt systems. Describe the function and operation of air bags. Identify the major parts of a typical air bag system. Safely disarm and inspect an air bag assembly. Know how to diagnose and service an air bag system.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Seat Belts 1. Ford’s Inflatable Rear Seat Belts A. Seat Belt Retractors B. Warning Lights II. Seat Belt Service A. Webbing Inspection B. Buckle Inspection C. Retractor Inspection D. Drive Track Assembly and Anchor Inspection E. Rear Seat Restraint System F. Warning Light and Sound Systems G. Servicing Seat Belts III. Air Bags A. Adaptive SRS Systems B. Electrical System Components 1. Sensors

3-41

Automotive Technology: A Systems Approach, 3Ce 2. 3. 4. 5. 6. 7. 8.

Roller-Type Sensors Mass-Type Sensor Accelerometer Diagnostic Monitor Assembly Wiring Harness Clockspring SIR/SRS or Air Bag Readiness Light Hint: Show several air bag sensors and explain how they operate. If possible, show an air bag that has been deployed. Arrange for students to observe the deployment and disposal of an air bag. Emphasize the safety practices the students need to know when working around areas of the vehicle related to air bags. C. Air Bag Module D. Diagnosis 1. Retrieving Trouble Codes IV. Servicing the Air Bag System A. Service Guidelines V. Other Protection Systems A. Head Rests B. Rollover Protection

ADDITIONAL TEACHING HINTS

• • •

Demonstrate the recommended method to disable the air bag systems and explain when this is necessary. Arrange for the students to witness the deploying of an air bag prior to its disposal. Dealership parts/service departments, body shops, and factory training facilities are possible sources for this activity.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Students may stumble with understanding the complete operation of a SRS. Ensure they understand the safety features in place for not only the owners’ safety but also their own. Ensure they understand the legal issues surrounding working on a vehicle’s air bag system and that no tampering or modifying can take place. Deploy an airbag (if possible) as a demonstration of the energy within the airbag.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Describe the conditions under which the driver- and/or passenger-side front air bag may be disabled. 2. List the government bodies that have the authority to authorize the deactivating of air bags.

3-42

Automotive Technology: A Systems Approach, 3Ce 3. List the procedures involved in disposing of a deployed air bag. NOTE: A live air bag must be deployed before it can be disposed of. CASE STUDY 4. A customer brings in her late-model car. The car has driver’s-side and passenger-side air bags. The air bag warning light is blinking and she is worried that the air bag may deploy while she is driving. What should you tell her and what procedure should you follow to stop the light from blinking?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. a. An active restraint system requires the vehicle’s occupant to manually connect or buckle a seat belt. A passive system operates automatically, with no action required of the occupant to make it functional. 2. d. The rear passenger centre seatbelt does not have a retractor. 3. d. Most seatbelts use a coil spring to remove seatbelt slack and position the occupant. A moving weight or inertia lock system may also be used to hold the seatbelt during an accident. 4. d. Two-stage deployment is used to limit the severity of air bag deployment. 5. c. It takes approximately 23 ms for the air bag to fully inflate. 6. b. Nitrogen is the gas generated to inflate the driver’s side air bag. 7. a. Argon is the gas used to inflate the passenger side air bag. 8. d. The two sensors that are used to deploy an air bag are safing and crash sensors. Both of these sensors must close to activate the air bag module. 9. c. The sensor deployment circuit is a series parallel circuit. The safing sensor is in series with the air bag and the crash sensors are parallel to the air bag. 10. c. Wait at least 30 minutes before beginning any service on or around the air bag system. 11. c. The clockspring provides a direct electrical connection to the air bag. The clockspring allows for steering wheel rotation while maintaining continuity between the circuit and the air bag. 12. b. Yellow is the most common colour used for air bag electrical connectors. This allows for easy identification of air bag connectors and circuits. 13. d. When servicing or storing a live air bag, always place the trim cover face up on a flat surface. In this position an unintentional deployment will only inflate the air bag without launching the assembly. 14. a. Talcum powder is one of the powders released from a deployed air bag. Talcum powder is used to keep the air bags lubricated and pliable while they are in storage. 15. c. The rapid burning of the sodium azide inflates the pyrotechnic air bag. A large quantity of nitrogen gas is produced by the burning sodium azide. 16. b. The use of a scan tool is the safest method of testing and diagnosing a live air bag that is still in place. Never back probe an air bag system with a self-powered multimeter, or a test light, unless you want to observe firsthand a very expensive bag deployment. 17. d. When scrapping a vehicle, all air bags should be safely deployed to prevent injury from future unintentional deployment. The air bag should be deployed and disposed of according to Environment Canada and the manufacturers’ recommendations. 18. b. The reserve energy supply provides a backup power supply to deploy the air bag in the event that the battery or cables are damaged during the accident. 19. b. The most effective location for air bag sensor placement is facing forward in the front radiator support area. 20. b. Modern crash sensors are usually accelerometers. ©2016 Nelson Education Ltd.

3-43

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 25 Ignition Systems CHAPTER OVERVIEW This chapter explains the basic principles of ignition systems and describes their components and how they function. The most common types of ignition systems are compared. Recent innovations are introduced with an explanation of their advantages.

LEARNING OUTCOMES

• •

Name and describe the three basic types of ignition systems.

Name the two major electrical circuits used in all ignition systems and their common components.

• • •

Describe the operation of ignition coils, spark plugs, and ignition cables. Explain how high voltage is induced in the coil secondary winding.

Describe the various types of spark timing systems, including electronic switching systems and their related engine position sensors.

• • •

Explain the basic operation of a computer-controlled ignition system. Describe the operation of a distributor-based ignition system. Describe the operation of a distributorless ignition system.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Basic Circuitry A. Primary Circuit Operation B. Secondary Circuit Operation 1. DI Systems 2. EI Systems II. Ignition Components A. Ignition Coils 1. Ignition Coil Construction 2. Secondary Voltage III. Spark Plugs 1. Size 2. Reach 3. Heat Range 4. Resistor Plugs 5. Spark Plug Gaps

4-1

Automotive Technology: A Systems Approach, 3Ce 6. Electrodes 7. Electrode Designs Hint: Show a variety of spark plugs and discuss the differences. A. Ignition Cables IV. Triggering and Switching Devices V. Engine Position Sensors A. Magnetic Pulse Generator B. Hall-Effect Sensor C. Magneto Resistive Sensor D. Photoelectric Sensor E. Metal Detection Sensors F. Timing Retard and Advance Hint: Show examples of each type of engine position sensor. VI. Distributor Ignition System Operation A. Distributor 1. Computer-Controlled DI Systems VII. Electronic Ignition Systems A. Double-Ended Coil or Waste Spark Systems 1. Waste Spark B. Coil-Per-Cylinder Ignition 1. Coil-Over-Plug (COP) Ignition C. Twin Spark Plug Systems VIII. Electronic Ignition System Operation A. Hall-Effect Sensors B. Magnetic Pulse Generators C. Magneto Resistive Sensors D. Misfire Detection E. Basic Timing 1. Timing Corrections

ADDITIONAL TEACHING HINTS

• • •

Discuss and compare breaker point, solid state, and computer-controlled ignition systems. Demonstrate a metal detection sensor, Hall-effect sensor, and a photoelectric sensor.

Demonstrate timing advance on an early HEI ignition system with vacuum and centrifugal advance and compare this to a later computer-controlled system.

•

Demonstrate setting the timing on an early HEI system and on a later computer-controlled system.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Students will have trouble understanding the concept of producing very high voltage from a 12-volt source. Use information from page 730 of Chapter 25 as well as a basic breaker point distributor if available to reinforce the concept. Again, if possible set up a breaker point distributor on a distributor machine (if available), and manipulate the point dwell setting and the physical movement to show how timing moves. Include information from page 751 of Chapter 25 that covers basic timing.

4-2

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On five different vehicles, identify the components of the ignition system and identify which ignition circuit they are part of. 2. On five different vehicles with EI systems, identify which ignition coils fire which spark plugs. Then explain how the engine’s firing order is maintained.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A pickup unit consisting of a coil of wire around a permanent magnet establishes a small magnetic field. The rotating timing disc (trigger wheel) moves through this field. As the teeth of the trigger wheel approach the alignment with the pickup coil, they disturb the magnetic field, causing it to concentrate around the pickup coil. Once the tooth passes, the magnetic field is free to expand until the next tooth approaches. This expansion and contraction of the magnetic field cuts across the windings of the pickup coil, inducing a small AC voltage signal that can be amplified elsewhere in the ignition system. 2. Dwell is the period of time in which current is flowing through the primary winding of the coil. The longer current is allowed to flow, the greater coil saturation will be. A fully saturated coil can better provide maximum secondary voltage. 3. Engine timing requirements are affected by engine speed and load. 4. Electronic ignition designs with two-plugs-per-coil use the waste spark method. Each end of the coil’s secondary winding is attached to a spark plug. When the magnetic field in the primary winding of the coil collapses, inducing extremely high voltage in the secondary winding, both plugs fire. One plug will fire in the normal direction, with the spark jumping from the centre electrode to the side electrode, and the other plug will fire with the spark jumping in the opposite direction. 5. A magnetic pulse generator has a pickup coil consisting of a permanent magnet with a coil of wire wound around it and a rotating toothed wheel called a timing disc, or trigger wheel. The permanent magnet in the pickup coil provides a magnetic field through which the trigger wheel moves. As the trigger wheel moves through the magnetic field, the field is distorted and an AC voltage is induced in the pickup coil winding. 6. a. When current flowing through the primary winding is interrupted, the magnetic field collapses and induces a high voltage surge in the coil secondary winding. 7. c. The electrons will jump across the path of least resistance. Therefore, spark plugs with multiple ground electrodes do not typically supply a spark to each electrode. 8. b. To generate a spark to begin combustion, the ignition system must deliver high voltage to the spark plugs. The amount of voltage or pressure required to bridge the gap of the spark plug varies with the operating conditions. Some late-model vehicle ignition systems can easily produce up to 60 000 volts to force a spark across the air gap. 9. d. Having one coil for each spark plug allows for more time between each firing (longer coil life), more saturation time (increased coil voltage output at high rpm), ignition timing at each cylinder can be custom tailored for maximum performance and to respond to knock sensor signals, all of the engine’s spark plugs fire in the same direction and coil failure will affect only one cylinder. 10. d. All ignition systems must be able to produce sufficient voltage to force the spark across the spark plug gap, deliver the spark to the appropriate cylinder at the correct time in

4-3

Automotive Technology: A Systems Approach, 3Ce relation to that cylinder’s piston position, and vary the spark arrival time based on the varying operating conditions. 11. c. Reach, heat range, and air gap are features of spark plugs. 12. a. The benefit of eliminating the spark plug wires when using COP ignition systems is that it reduces both EMI and RFI. 13. a. Variable pitch resistor spark plug wires are used to reduce the impedance of the wire. 14. d. The magnetic field surrounding the coil in a magnetic pulse generator moves when the reluctor tooth approaches or begins to move away from the pickup coil pole. 15. c. A Hall-effect sensor has shutters rather than teeth. 16. b. A magnetic style crank sensor produces a variable AC signal. 17. c. A Hall-effect sensor produces a signal that is amplified, inverted, and shaped into a clean square wave frequency signal. 18. b. A misfire monitor uses the crank sensor to determine misfires. 19. c. Engine ignition timing is controlled by opening the ignition primary circuit? 20. b. A knock sensor is used to detect preignition and detonation in an engine and reacts by retarding the timing when it receives a signal.

4-4

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 26 Ignition System Diagnosis and Service CHAPTER OVERVIEW This chapter describes ignition system inspection and testing techniques. Included is how to use an oscilloscope to monitor various phases of ignition system performance. The testing procedures described can be demonstrated in the shop.

LEARNING OUTCOMES

• Perform a no-start diagnosis and determine the cause of the condition. • Determine the cause of an engine misfire. • Perform a visual inspection of ignition system components, primary wiring, and secondary wiring to locate obvious trouble areas.

• • • • • • •

Describe what an oscilloscope is, its scales and operating modes, and how it is used in ignition system troubleshooting. Test the components of the primary and secondary ignition circuits. Test individual ignition components, using test equipment such as a voltmeter, ohmmeter, and testlight. Service and install spark plugs. Describe the effects of incorrect ignition timing. Check and set (when possible) ignition timing. Diagnose engine misfiring on electronic ignition–equipped engines.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Misfires A. Abnormal Combustion II. General Ignition System Diagnosis A. Common vs. Non-Common Problems III. Ignition System Inspection A. Scan Tools B. Primary Circuit C. Ground Circuits D. Electromagnetic Interference E. Sensors F. Control Modules G. Secondary Circuit

4-5

Automotive Technology: A Systems Approach, 3Ce H. Distributor Cap and Rotor IV. No-Start Diagnosis A. No-Start Diagnosis of EI Systems V. Diagnosing with an Engine Analyzer A. Cylinder Performance Test B. Ignition Performance Tests C. Scope Patterns 1. Scales 2. Understanding Single Cylinder Patterns 3. Pattern Display Modes 4. Spark Plug Firing Voltage 5. Spark Duration 6. Coil Condition 7. Primary Circuit Checks D. Stress Testing Components 1. Cold Testing 2. Heat Testing 3. Moisture Testing E. Testing with a Scan Tool VI. Diagnosing with a DSO or GMM A. Using the DSO or GMM B. Testing the Ignition System 1. An Undetected Cylinder VII. Ignition Timing A. Setting Ignition Timing VIII. Basic Primary Circuit Components A. Ignition Switch B. Ignition Coil Resistance 1. High-Voltage Diodes C. Crankshaft/Camshaft Sensors D. Pickup Coils 1. Voltmeter Checks E. Hall-Effect Sensors F. Using a Logic Probe G. Using a Lab Scope H. Knock Sensors I. Control Module IX. Distributor Service X. Secondary Circuit Tests and Service A. Distributor Cap and Rotor B. Waste Spark Systems C. Coil-over-Plug Systems D. Spark Plugs E. Inspecting Spark Plugs 1. Carbon Fouling 2. Wet Fouling 3. Glazing 4. Overheating 5. Turbulence Burning

4-6

Automotive Technology: A Systems Approach, 3Ce 6. Preignition Damage Hint: Provide examples of each of the conditions just listed. Have the students identify the condition and the possible causes. F. Regapping Spark Plugs G. Secondary Ignition Wires 1. Resistance Checks H. Replacing Spark Plug Wires

ADDITIONAL TEACHING HINTS

• • • • • •

Demonstrate how to conduct a complete visual inspection of an ignition system. Discuss open circuit precautions. Perform installing and timing the distributor. Demonstrate the advantages of individual component testing in ignition systems. Use a shop car or other available vehicle to conduct a variety of no-start troubleshooting exercises. Use a shop car or other available vehicle to conduct a variety of misfire troubleshooting exercises.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Students new to the automotive trade will struggle with understanding the diagnosis of an ignition system especially when using an oscilloscope to analyze ignition patterns. Use a single cylinder pattern along with Chapter 26’s information on page 763 on “Diagnosing with An Engine Analyzer.” Create an open and a short in the secondary and discuss the patterns. Ensure that students understand the evolution of ignition systems and that the newest COP systems are doing exactly what the older breaker point systems were doing only on a much more precise scale with regards to timing, and their ability to deliver a much higher secondary voltage for today’s leaner running engines.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Working with a partner, take turns removing a spark plug from a vehicle and shorting out the ground electrode to create a misfire. Using the test equipment available, follow procedures to locate the faulty spark plug. Record your step-by-step procedures. CASE STUDY 2. A technician is working on a Chevrolet S-10 pickup. After seeing a low firing line on the number 4 cylinder, what would the technician do next?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. There are three ways to stress test electronic components. Both cold testing and heat testing involve directing either cold or heat onto the component and observing for

4-7

Automotive Technology: A Systems Approach, 3Ce signs of malfunction using the appropriate test equipment. Moisture testing involves lightly spraying the component with moisture and looking for signs of failure. 2. Ignition coil resistance with a waste spark ignition system is tested slightly differently because there are two secondary terminals instead of one. Connect an ohmmeter to each of the secondary terminals and compare to specifications. 3. An oscilloscope may be used to display either parade, raster, or superimposed patterns. The parade pattern is useful to easily compare voltage peak differences from cylinder to cylinder. The raster pattern is used to easily compare the timing of events in the ignition system. A superimposed pattern allows identification of the cylinder whose pattern differs from that of the other cylinders. 4. The common types of spark plug fouling are: a. Cold fouling, in which there could be an excessively rich air/fuel mixture. Or the plug might not be firing due to an ignition system fault or a mechanical failure involving the cylinder. b. Wet fouling, in which there is excess oil in the combustion chamber. c. Splash fouling, which results after an overdue tune-up when combustion chamber deposits can foul the new plugs. Avoid high speed driving immediately after a tune-up. d. Gap bridging, in which stop-and-go driving causes carbon deposits to accumulate in the combustion chamber that can melt and bridge the spark plug gap when the engine is placed under load. e. Glazing, caused by high-speed driving and wide-open throttle acceleration. f. Overheating, resulting from incorrect heat range, overadvance timing, excessively lean fuel mixture, cooling system failure, low fuel octane rating, incorrectly installed plugs, or a stuck heat riser valve. g. Turbulence burning, in which overheating can be the problem if premature wear is evident. h. Preignition damage, caused by excessive engine temperatures. 5. A Hall-effect sensor can be tested by using either a logic probe or a lab scope, or with a 12-volt source and a voltmeter. 6. d. If the gap between the centre electrode and one of the ground electrodes is less than that of the others on a spark plug that has more than one ground electrode, the spark will occur only at the smallest gap. 7. a. Input signals should always be checked before checking output signals. 8. b. Leaner air/fuel mixtures increase the electrical resistance inside the cylinder and increase the required firing voltage. 9. d. The ignition module would be considered a “common” ignition problem. 10. c. The time the spark actually lasts is represented by the spark line. The spark line begins at the firing line and continues until the voltage from the coil drops below the level needed to keep current flowing across the gap. 11. a. You should use a non-magnetic feeler gauge to measure the air gap of a crankshaft or camshaft sensor. 12. a. A cylinder performance test measures the rpm drop of each cylinder as it is turned off during the test. 13. c. While checking a pickup coil with an ohmmeter, a higher-than-normal reading indicates that the pickup coil has high resistance. 14. b. A Hall-effect CKP sensor can be checked with a voltmeter. 15. a. High resistance in a spark plug wire will cause one firing line to be higher than the rest. 16. c. High resistance in the coil wire could cause all of the firing lines to be abnormally high. 17. c. A P0300 series code indicates a problem with a misfiring cylinder. 18. a. A P0200 series code indicates a problem with the fuel injector system. 19. c. Using a fuel with too low an octane rating can cause overheated spark plugs.

4-8

Automotive Technology: A Systems Approach, 3Ce 20. c. When using a logic probe, a red light indicates more than 10 volts at the test point.

CHAPTER 27 Gasoline, Diesel, and Other Fuels CHAPTER OVERVIEW This chapter describes the common fuels used as energy sources for automobiles. Gasoline and diesel fuel are compared and their differences and similarities discussed. Diesel delivery and emission systems are also covered.

LEARNING OUTCOMES

• • • • • • • •

Describe the basic composition of gasoline. Explain why materials are added to gasoline to make it more efficient. Name the common substances used as oxygenates in gasoline and explain what they do. Describe how the quality of a fuel can be tested. Explain the advantages and disadvantages of the various alternative fuels. Explain the differences between diesel fuel and gasoline. Describe the common types of fuel injection used on today’s diesel engines. Describe the various techniques used to allow current diesel engines to meet emission standards.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Crude Oil A. Petroleum Products 1. Hydrocarbons B. Refining 1. Chemical Processing 2. Cleaning and Blending C. Concerns II. Gasoline A. Antiknock Quality B. Volatility 1. Cold Starting and Warm-up 2. Altitude 3. Crankcase Oil Dilution

4-9

Automotive Technology: A Systems Approach, 3Ce C. Sulphur Content 1. Deposit Control III. Basic Gasoline Additives A. Anti-Icing or Deicer B. Metal Deactivators and Rust Inhibitors C. Gum or Oxidation Inhibitors D. Detergents IV. Oxygenates A. Ethanol B. Methanol C. MTBE D. Aromatic Hydrocarbons Hint: Discuss gasoline and how its formulation has been influenced by environmental concerns. Discuss how performance has been affected. V. Gasoline Quality Testing A. Testing the RVP of Gasoline B. Alcohol in Fuel Test VI. Alternatives to Gasoline A. Alternate Fuels 1. Energy Density B. Ethanol C. Methanol D. Propane/LPG E. Compressed Natural Gas 1. Honda Civic Natural Gas Vehicle 2. P-Series Fuels F. Hydrogen 1. Hydrogen Fuel 2. Infrastructure and Storage G. Flex Fuel Vehicles VII. Diesel Fuel A. Cetane Ratings B. Grades of Diesel Fuel C. Biodiesel Fuels D. Ultra-Low Sulphur Diesel Fuel VIII. Diesel Engines A. Diesel Combustion B. Engine Control Systems IX. Diesel Fuel Injection A. Injector Nozzles B. Electronic Unit Injection (EUI) C. Hydraulic Electronic Unit Injection (HEUI) 1. Operation 2. Importance of Maintenance D. Common Rail Injection 1. High-Pressure Pump 2. Injector Control 3. Processing 4. Inputs 5. Outputs E. Solenoid Injectors

4-10

Automotive Technology: A Systems Approach, 3Ce F. Piezoelectric Injectors G. Fuel Delivery 1. Timing the Pumps H. Turbochargers X. Diesel Emission Controls A. Diesel Oxidation Catalysts B. Diesel Exhaust Particulate Filter 1. Ash Loading C. Exhaust Gas Recirculation (EGR) Systems D. Selective Catalytic Reduction Systems E. Positive Crankcase Ventilation (PCV) Systems F. TDI Engines 1. Audi TDI R10/15 Vehicles XI. Diagnostics A. Diesel Exhaust Smoke Diagnosis 1. Gaseous Emissions 2. Liquid Emissions 3. Solid Emissions B. Compression Testing 1. Cylinder Balance Test C. Injector Opening Testing

ADDITIONAL TEACHING HINT

•

Conduct an experiment testing gasoline, 2D diesel, and alcohol. A sample of each fuel can be placed in a small fireproof container with a tight-fitting lid (glass ovenware or chemistry lab supplies) that will be used to extinguish flames. Volatility can be observed by the presence of fumes above the gasoline and the lack of such fumes above the diesel fuel. If conditions are safe to burn a small sample of each fuel, there will be a noticeable difference in the amount of energy released in the form of heat by each type of fuel. Discuss the relative difference in the energy content of different fuels as expressed by their BTUs/gallon rating. The lid can be used to extinguish flames, and a fire extinguisher should be nearby.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Students will not typically see the importance of the additives used in gasoline or diesel fuel. Reinforce the importance by leaving samples of each of the fuels in a container for a period of time and observe what happens as they evaporate. Ensure the students understand the large difference between diesel fuel and gasoline. Use information from page 794 of Chapter 27 referring to gasoline and page 804 referring to diesel fuel. Even though they both are derived from crude oil, their refining and end products are very different.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using two different late-model vehicles equipped with diesel engines, locate and record the emission control devices used on each vehicle.

4-11

Automotive Technology: A Systems Approach, 3Ce

CASE STUDIES 2. A customer has taken his car out of storage after it has been locked up and not driven for two years. Prior to putting it away, he did not drain the fuel. What driveability problems might he face and what test can be conducted to verify the likely problem? 3. A customer brings in his diesel pickup truck complaining of a smell of diesel fuel. Using your knowledge of the fuel delivery system, locate the source of the leak. List all of the fuel delivery components under the hood of the pickup that could be the cause of the leak.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Problems that can arise from an excessive amount of alcohol in gasoline are: fuel system corrosion, fuel filter plugging, deterioration of rubber fuel system components, and a lean air-fuel ratio 2. False. The cetane rating of diesel fuel is a measure of its ignition quality, not its antiknock quality. 3. E85 contains 85 percent ethanol. 4. Advantages of piezoelectric injectors over solenoid injectors are: they offer improved fuel economy, since there are no moving parts, they have a longer life, they reduce combustion noise, they allow for more precise and rapid control of injection intervals, they offer improved combustion, they reduce exhaust emissions, they can allow seven or more smaller and staggered sprays of fuel during a single power stroke. 5. RVP is a measure of the volatility of gasoline. 6. d. Ethanol is typically added to gasoline to increase its octane rating 7. c. Conductivity is unlikely to affect the performance of fuel. 8. c. The stoichiometric ratio for gasoline is 14.7 to 1. This refers to 14.7 parts of air for 1 part of gasoline by weight. 9. b. Isopropyl alcohol is added to gasoline in cold weather to prevent fuel line freezeup. 10. a. The use of a hemispherical shaped combustion chamber will reduce the chances of detonation. With the spark plug located in the centre of the combustion chamber, the even flame propagation from the centre produces a faster more complete combustion. 11. c. Methanol is a commonly used oxygenate in gasoline. Methanol is also used as an octane enhancer when blended with gasoline. 12. a. Fuel detergents do not affect the octane rating of a fuel and therefore have no effect on engine knock. 13. a. Gasoline contains carbon and hydrogen. The chemical symbol for gasoline is C8H15 meaning, 8 carbon atoms and 15 hydrogen atoms combine to form gasoline. 14. b. Ethanol is a type of fuel that derives almost exclusively from corn. 15. d. Aromatic amines are commonly used in gasoline to reduce gum and varnish formation. 16. d. Methylcyclopentadienyl manganese tricarbonyl (MMT) is currently added to gasoline to obtain the desired octane rating. 17. b. A Reid vapour pressure (RVP) test is performed at 38°C (100°F). 18. b. Urea is commonly used as a reductant in the SCR systems of diesels 19. c. 50 is a common cetane rating for today’s diesel fuel. 20. c. The reductant in the SCR breaks down NOX into water vapour and nitrogen (N2),

4-12

Automotive Technology: A Systems Approach, 3Ce

4-13

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 28 Fuel Delivery Systems CHAPTER OVERVIEW The fuel system is responsible for supplying clean fuel in the correct quantities and pressure to the injectors. This chapter shows how to inspect and service the fuel delivery system. The fuel injection system is discussed in later chapters.

LEARNING OUTCOMES

• • • • • • • • • •

Describe the components of a fuel delivery system and the purpose of each. Conduct a visual inspection of a fuel system. Relieve fuel system pressure. Inspect and service fuel tanks. Inspect and service fuel lines and tubing. Describe the different fuel filter designs and mountings. Remove and replace fuel filters. Explain how common electric fuel pump circuits work. Conduct a pressure and volume output test on an electric fuel pump. Service and test electric fuel pumps.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Basic Fuel System Diagnosis A. Contaminated Fuel II. Guidelines for Safely Working on Fuel Systems Hint: Discuss how to safely relieve fuel pressure prior to opening the system. III. Fuel Tanks A. Inspection B. Fuel Tank Draining C. Fuel Tank Service Hint: Discuss ways to safely drain the fuel tank. IV. Filler Caps A. OBD-II Monitor B. Fuel Cap Testing C. Capless Fuel System

4-14

Automotive Technology: A Systems Approach, 3Ce V. Fuel Lines and Fittings A. Fittings Hint: Show examples of threaded and quick-disconnect fittings. Demonstrate the proper release tools used with quick-disconnect fittings. B. Inspection C. Line Replacement VI. Fuel Filters A. Servicing Filters VII. Fuel Pumps 1. Diesel Engines A. Fuel Pump Circuits 1. Return Type B. Rollover Protection 1. Passive Restraint Systems C. Returnless Systems D. Troubleshooting 1. Interpreting the Results 2. Residual Pressure 3. Fuel Volume Test 4. Using a Lab Scope 5. Using a DMM E. No-Start Diagnosis Hint: Show several types of fuel pumps. Discuss the control circuits and explain how to differentiate between a failed fuel pump, low fuel pressure, and a circuit failure. F. Replacement 1. Internal Fuel Pump

ADDITIONAL TEACHING HINTS

• • • • • • •

Demonstrate fuel pump pressures on fuel injection and carburetor type vehicles and discuss the differences. Arrange for an electric vehicle demonstration either at a dealership or in your shop. Demonstrate how the fuel pump relay operates on a fuel injected car. Demonstrate how to safely relieve fuel pressure prior to opening the system. Demonstrate disconnecting quick-disconnect fuel line fittings. Demonstrate fuel pump pressure and volume testing. Have the students locate the fuel pump relay using an electrical component locator.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Ensure students understand the importance placed on evaporative emissions with modern vehicles. Vapour leaks are very hard to detect and understanding that there may be no signs of liquid fuel leaking will compound the fault. Students should also have a good understanding of the safety features built into today’s vehicles in case of a collision. Review the section covering rollover protection on page 842 of Chapter 28.

4-15

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On a vehicle assigned to you, locate the fuel delivery system and make a diagram of it. Include in your drawing the fuel lines, fuel pump, fuel filter, fuel pressure regulator, and return lines. 2. On a vehicle assigned to you, explain the operation of the fuel pump circuit. Use the appropriate service information and wiring diagram to guide you. 3. Using a vehicle equipped with a returnless fuel delivery system, list all of the components involved in delivering fuel as well as a wiring diagram showing all of the sensors involved in determining the amount of fuel to be delivered. CASE STUDY 4. A customer reports that he smells a fuel odour after parking his vehicle following a long drive. What could be the cause?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. capacity 2. The relief valve protects fuel system components from excessive fuel pressure. The one-way check valve prevents fuel from draining from the underhood components and returning to the tank. 3. There should be a Class B fire extinguisher nearby when working on fuel systems. 4. Before disconnecting and removing a fuel tank, always disconnect the negative battery terminal first. 5. A restrictor is placed in the vapour-vent hose to control the rate of vapour flow from the tank to the vapour storage tank. 6. d. A high fuel pressure reading could be caused by a faulty fuel pressure regulator. A restricted fuel return line could also be a possible cause. 7. b. On port fuel injected vehicles the test port is usually located on the fuel rail. 8. c. Some filler caps contain a pressure valve and a vacuum relief valve. The vacuum relief valve will allow air in to relieve high gas tank vacuum. 9. a. Quick-connect gasoline line fittings use O-rings in the female connector to seal the fitting. 10. b. A typical fuel filter replacement interval would be 48 000 km (30 000 miles). 11. a. A clogged fuel return line could cause a rich air/fuel mixture. Excessive fuel pump pressure can be caused by a restricted return line which in turn can allow higher fuel delivery by the injectors. 12. c. A faulty fuel pump relay could cause no voltage present at the fuel pump terminal with the key on and the engine cranking. A faulty pressure regulator would only affect the operating pressures while a poor pump ground would prevent pump operation but power would still be present.

4-16

Automotive Technology: A Systems Approach, 3Ce 13. a. The purpose of the inertia switch is to open the fuel pump circuit in the case of a collision or roll over. These switches have a reset button that must be depressed to close the circuit before the pump will operate again. 14. c. Fuel pressure rises when a loss of vacuum occurs at the fuel pressure regulator. 15. a. The first step in removing a fuel tank is to remove the negative battery cable to prevent fuel pump operation. Prior to battery cable removal, fuel pressure should be bled off. 16. d. Most fuel line O-rings are made from Viton. Viton resists deterioration from gasoline. 17. a. When a steel fuel line is damaged and requires replacement, it should be replaced with a steel line. It is recommended that any damaged fuel line be replaced with one of similar construction. 18. c. A buzzing sound coming from the fuel tank is an indication that the fuel pump is operating. 19. a. The PCM provides the fuel pump relay ground for the fuel pump to operate on most Chrysler cars with electronic fuel injection. 20. d. A strainer is located on the fuel pump inlet or on a pickup tube to prevent large contaminants from entering the fuel system. Smaller dirt particles will be trapped by the fuel filter downstream from the fuel pump.

4-17

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 29 Electronic Fuel Injection CHAPTER OVERVIEW Electronic fuel injection is the most precise, reliable, and effective method of delivering fuel to the combustion chamber. This chapter discusses the common components found in most electronic fuel injection (EFI) systems and explains how various EFI designs operate. This is a discussion of typical systems and not an attempt to include all of the variations. Understanding the operation of typical systems provides a foundation that will lead to a better understanding of any variations when they are encountered.

LEARNING OUTCOMES

• • • •

Explain the differences in the point of injection in throttle body or port injection systems. Describe the difference between a sequential fuel injection (SFI) system and a multiport fuel injection (MPFI) system. Explain the design and function of major EFI components. Describe the inputs used by the computer to control the idle air control (IAC) and IAC bypass air motors.

• Describe how the computer supplies the correct air/fuel ratio on a throttle body injection (TBI) system.

• Explain how the clear flood mode operates on a TBI system. • Explain why manifold vacuum is connected to the pressure regulator in an MPFI system. • Describe the operation of the pressure regulator in a returnless EFI system. • Describe the operation of the central injector and poppet nozzles in a central multiport fuel injection (CMFI) system.

• Describe the operation of direct gasoline injection systems. • Describe the operation of injection systems used in light- and medium-duty diesel engines. INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Basic EFI A. Fuel Injectors Hint: Pass around various types and styles of injectors and discuss the merits of each and which type of fuel injection system they are used in. B. Idle Speed Control C. Inputs 1. MAF Sensor

4-18

Automotive Technology: A Systems Approach, 3Ce

II. III.

IV.

2. MAP Sensor 3. Oxygen Sensors (O2S) 4. IAT Sensor 5. ECT Sensor 6. APP/TP Sensors 7. CKP Sensor 8. CMP Sensor 9. Additional Input Information Sensors D. Operational Modes 1. Starting Mode 2. Run Mode 3. Clear Flood Mode 4. Acceleration Mode 5. Deceleration Mode E. Fuel Trim Throttle Body Injection (TBI) Port Fuel Injection (PFI) A. Multiport Fuel Injection Systems (MPFI) B. Sequential Fuel Injection Systems C. Throttle Body D. Fuel Delivery 1. Pulsation Damper E. Injector Control F. Pressure Regulators 1. Returnless Systems G. Throttle-By-Wire System Central Port Injection (CPI) A. Pressure Regulator B. Injector Design and Operation C. Poppet Nozzles Gasoline Direct Injection (GDI) A. Injectors B. High-Pressure Fuel Pump C. Operational Modes 1. Lean Burn Mode 2. Stoichiometric Mode 3. Full-Power Mode D. Compression Ratios E. Advantages of GDI F. GDI Plus SFI

ADDITIONAL TEACHING HINT

•

Demonstrate using a multimeter and an oscilloscope to show examples of input sensor signals.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

It will be difficult for the students to “see” the effects of a lean to rich change in fuel delivery. Use scan tool data to show the oxygen sensor response to creating a lean or a rich mixture.

4-19

Automotive Technology: A Systems Approach, 3Ce • •

Refer to the heading “Oxygen Sensors” on page 859 of Chapter 29 to help the students understand the concept. To help the students understand the delivery of fuel to the different types of injection systems, bring in an example of each and point out the differences and similarities. Refer to the sections starting with “Throttle Body Injection” on page 861 of Chapter 29 to aid with the lesson.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On five different vehicles, determine the type of fuel injection the engine is fitted with and describe the operational characteristics of each. 2. On a vehicle with direct injection, list and locate all of the components used in the delivery of fuel to the engine. Record the fuel pressures that each vehicle operates at. 3. On a vehicle assigned to you, locate the input sensors for the engine control system. List them and compare your findings with the information given in the service information system. When you are finished, give a tour of the system to your instructor.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Throttle-body fuel injection delivers fuel to a central point near the throttle plate. Port fuel injection has one injector per cylinder and the fuel is delivered to each cylinder at a point in the intake port near the intake valve. 2. Sequential firing of the injectors provides fuel by opening each injector just before the intake valve opens. 3. A speed-density fuel injection system calculates the amount of air entering the engine based on input from the MAF or the MAP sensor, engine rpm, and throttle position. Input from the TP sensor is vital for an accurate calculation. 4. The coolant temperature sensor signals the computer when the engine needs cold enrichment such as during starting and warm-up. Injector pulse width is increased for cold enrichment. 5. The computer controls the air/fuel mixture in an EFI system based on input from various sensors by varying injector pulse width. 6. a. The O-ring at the base of the fuel injector seals the injector to the intake manifold to prevent at intake manifold vacuum leak at the injector. 7. c. Duty cycle is the percentage of time a solenoid is energized relative to the total cycle time. 8. d. In an engine equipped with gasoline direct injection (GDI), the gasoline is injected into the cylinder. 9. c. A warm engine operating at cruising speed would be operating in closed loop. 10. b. In a sequential fuel injection system each injector is fired individually. 11. a. At idle the fuel pressure regulator has the most vacuum controlling it. When the engine is idling, the pressure regulator provides lower fuel pressure compared to the fuel pressure at wide-open throttle.

4-20

Automotive Technology: A Systems Approach, 3Ce 12. b. The typical fuel injector pulse width range is from 1 ms at idle to 10 ms at full load. This means the injectors have more time to deliver fuel under higher fuel demand. 13. d. The MAP sensor measures engine load by monitoring intake manifold pressure. Intake manifold pressure will change under different engine loads and rpm. 14. b. The IAC controls idle speed by changing the amount of air that bypasses the throttle plate. 15. d. The length of time that an injector is energized or on-time is called pulse width. 16. c. The typical air/fuel ratio during clear flood mode is 18:1. 17. b. The mass airflow sensor measures the density of the air entering the intake manifold. 18. a. Another name for a lambda sensor is an exhaust gas oxygen sensor. 19. d. The PCM is responsible for adjusting fuel injection duration. When in closed loop, the PCM reacts to sensor inputs to adjust the fuel injector pulse width. When conditions, such as starting, cold or wide open throttle, demands that the oxygen sensor be ignored, the computer operates in open loop. In open loop the injector pulse width is controlled by set parameters contained in the PCM’s memory. 20. c. The main difference between port fuel injectors and direct fuel injectors is that direct injectors spray fuel at higher pressure (typically between 2760 and 10 350 kpa [400 and 1500 psi]). Special fuel injectors are needed for GDI systems due to much higher injection pressures and the need to seal the injector to prevent heat from igniting the fuel in the injector.

4-21

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 30 Fuel Injection System Diagnosis and Service CHAPTER OVERVIEW Diagnosing and servicing fuel injection systems requires systematic, step-by-step procedures. This chapter describes how to diagnose typical fuel injection systems and to perform routine maintenance and repairs.

LEARNING OUTCOMES

• • • • • • • • • •

Perform a preliminary diagnostic procedure on a fuel injection system. Remove, clean, inspect, and install throttle body assemblies. Explain the results of incorrect fuel pressure in a TBI, MPFI, or SFI system. Perform an injector balance test and determine injector condition. Clean injectors on an MPFI or SFI system. Perform an injector sound, ohmmeter, noid light, and scope test. Perform and injector flow test and determine injector condition. Perform an injector leakage test. Remove and replace the fuel rail, injectors, and pressure regulator. Diagnose causes of improper idle speed on vehicles with fuel injection.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Preliminary Checks 1. EFI System Component Checks II. Service Precautions III. Basic EFI System Checks A. Oxygen Sensor Diagnosis B. OBD-II Adaptive Fuel Control Strategy C. Air Induction System Checks Hint: Discuss intake manifold and throttle body cleaning methods and why they are necessary. D. Airflow Sensors 1. Mass Airflow Sensors 2. Volume Airflow Sensors 3. Karman Vortex Sensors 4. Speed Density (MAP) Systems E. Throttle Body

4-22

Automotive Technology: A Systems Approach, 3Ce 1. Throttle Body Inspection 2. Throttle Body Removal and Cleaning F. Fuel System Checks 1. Fuel Delivery G. Injector Checks 1. Checking Voltage Signals 2. Injector Balance Test 3. Injector Sound Test 4. Injector Flow Testing 5. Oscilloscope Checks (a) Peak and Hold Injectors (b) Pulse-Width-Modulated Injectors 6. Current Ramping IV. Injector Service A. Injector Cleaning B. Ultrasonic Cleaning Hint: Discuss various injector cleaning methods and compare the merits of each. Point out precautions that should be observed. V. Fuel Rail, Injector, and Regulator Service A. Injector Replacement B. Fuel Rail, Injector, and Pressure Regulator Removal C. Special GDI Checks VI. Electronic Throttle Controls A. Diagnostic Monitors 1. Fail-Safe Mode B. Idle Speed 1. Idle Learn C. General Diagnostics VII. Idle Speed Checks A. IAC Checks B. Servicing the IAC Motor

ADDITIONAL TEACHING HINTS

• Demonstrate what happens when one injector on a TBI system is disconnected. • Demonstrate the effects of a manifold vacuum leak at the pressure regulator in an MPFI system. • Demonstrate the spray patterns of a good and bad fuel injector using water. • Demonstrate how to hook up a scan tool and what the readings mean on a problem-free vehicle. • Demonstrate how to bleed-down and remove TBI and MPFI injectors for inspection, cleaning, and testing.

• •

Show the activity of a fuel injector and oxygen sensor on a lab scope. Demonstrate idle speed checks using the various meters and scan tools.

4-23

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

This will be one of the more difficult concepts for students to grasp, connecting test equipment to a vehicle is easy enough but understanding the readings and interpreting them into a diagnosis to repair the vehicle is much more difficult. One of the best ways to help with this understanding is to connect test equipment to a good running vehicle and look at readings while inputs are manipulated. Watch and record the resulting fuel injector pulse width while forcing a vehicle rich and lean as an example.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Under the guidance of your instructor and with the equipment available in the shop, clean the injectors on a vehicle. Measure the exhaust levels before and after the cleaning and explain what happened. CASE STUDIES 2. A customer brings in her late-model car with port-type injection. She complains of hard starting and poor gas mileage. What tests should be conducted to identify the problem? 3. A technician is working on a vehicle that came to the shop with a complaint of poor gas mileage and a lit MIL. The technician connects a scan tool to the computer and finds that the engine coolant temperature sensor or its wiring could be faulty. Before checking further, he ponders over the other customer complaint. Can you help him by explaining how a faulty ECT could cause poor fuel mileage?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. For an EFI system to operate properly, it needs (1) an adequate air supply, (2) the correct fuel pressure provided for properly operating injectors, and (3) the correct trigger signal from the computer received by the injector. 2. Trouble codes (fault codes) are numerical indications of the circuit or portion of a circuit in which a problem has been detected by the onboard diagnostics. They do not pinpoint the specific component at fault and should not be used as a signal to replace components. They signal that a more thorough diagnosis is needed to identify and verify the source of the failure. 3. Check an oxygen sensor by connecting a voltmeter between the O2 sensor wire and ground, and observing the voltage variations as the air/fuel mixture fluctuates between rich and lean. The voltage range for most O2 sensors is from 0 to 1 volt. (Some DaimlerChrysler engines use a 5-volt reference signal and so the voltmeter will read 5–6 volts.) When the voltage is closer to 1 volt, the mixture is rich; when it is near zero, the mixture is lean. A good sensor should actively cycle between rich and lean about 10–40 times in 10 seconds, indicating that the computer is modulating fuel mixture in response to sensor input. 4. OBD-II compliant vehicles use adaptive fuel control strategies referred to as shortterm fuel trim (STFT) and long-term fuel trim (LTFT) to make adjustments to fuel control calculations. STFT begins when the engine goes into closed loop and the computer begins recognizing input from the O2 sensors. Once the engine reaches a predetermined operating temperature (typically about 180°F), the PCM begins to

4-24

Automotive Technology: A Systems Approach, 3Ce update the LTFT based on engine speed and STFT. STFT works to bring LTFT close to 0 percent correction. A rich condition will be indicated by a –LTFT number and a lean condition will be indicated by a +LTFT number on the scan tool. 5. When block integrator or Block Learn numbers are constantly below 128, the computer is continually decreasing fuel, indicating a rich condition or high O2 sensor voltage. 6. d. If a mass air flow (MAF) sensor is suspected of causing a no-start condition, unplug the sensor and attempt to start the engine. If it starts, the sensor should be replaced. 7. d. Any item in the O2 sensor circuit can set off an O2 sensor trouble code. Whether wiring, connectors or the sensor is at fault, any problem that affects the voltage in the sensor circuit can produce an O2 sensor code. Low voltage to the computer indicates a lean mixture which will make the computer respond by adding fuel to the mixture. 8. c. The computer’s adaptive memory would likely cause a rough engine idle after injectors are cleaned or replaced. The adaptive memory will still supply the increased pulse width required for the dirty injectors to the now clean injectors. This will cause the air/fuel ratio to be too rich. 9. c. Test an injector with an ohmmeter by disconnecting the wiring connector and connecting the ohmmeter leads across the injector terminals. Compare to specifications. If the injector is even a little bit outside of specifications, it should be replaced. 10. a. During an injector balance test, a low-pressure drop on one injector would indicate a restricted injector. A restricted orifice or tip would likely be the cause of the restriction. Any injector that does not operate within specifications should be cleaned or replaced. 11. a. The duty cycle of an injector is the percentage of on-time to total cycle time. 12. b. Engine oil should be used on the injector sealing O-ring when installing an injector. Avoid using silicone grease which can clog the injector. 13. b. An O2 sensor can be checked by the use of a voltmeter with its leads between the sensor lead and ground. The sensor’s voltage should be cycling from low to high voltage. 14. d. An O2 sensor must reach approximately 315.6°C (600°F) to function in closed loop mode. 15. a. An injector balance test is performed to verify the injector’s delivery volume. Each pulse of the injector should dispense a specific volume and each volume drop should produce a measurable drop in pressure. 16. b. The correct method to clean an injector is to run a chemical cleaner through it. 17. d. A correctly operating O2 sensor should produce a varying voltage output between 0.2 volts and 0.8 volts. 18. d. A heated oxygen sensor usually requires four wires. Two wires are required for the sensor and two wires for the heater. 19. d. The correction for a lean condition would be +10% 20. c. The correction for a rich condition would be −10%.

4-25

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 31 Engine Performance Systems CHAPTER OVERVIEW This chapter covers the major concepts involved in the self-monitoring and self-diagnosing of the computer control systems used in today’s vehicles.

LEARNING OUTCOMES

• • • • • • • • • • • • • • •

State the purpose of the major engine performance systems/components. Explain what is meant by open loop and closed loop. Explain the reasons for OBD-II. Explain the requirements to illuminate the malfunction indicator light in an OBD-II system. Briefly describe the monitored systems in an OBD-II system. Describe an OBD-II warm-up cycle. Explain trip and drive cycle in an OBD-II system. Describe how engine misfire is detected in an OBD-II system. Describe the differences between an A misfire and a B misfire. Describe the purpose of having two oxygen sensors in an exhaust system. Briefly describe what the comprehensive component monitor looks at. Retrieve and record stored diagnostic trouble codes, and clear codes. Diagnose the causes of emissions or driveability concerns resulting from malfunctions in the computerized engine control system with stored diagnostic trouble codes. Diagnose emissions or driveability concerns resulting from malfunctions in the computerized engine control system with no stored diagnostic trouble codes, and determine necessary action. Obtain and interpret scan tool data.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Ignition Systems A. Purpose of the Ignition System B. Ignition Timing C. Firing Order D. Computer-Controlled Systems II. Fuel System A. Fuel Injection

4-26

Automotive Technology: A Systems Approach, 3Ce III. Air Induction System A. Air/Fuel Mixtures IV. Emission Control Systems A. Computer-Controlled Systems V. Engine Control Systems A. System Components B. Computer Logic C. Additional Engine Controls 1. Electronic Throttle Control 2. Variable Intake Manifolds D. Control of Non-Engine Functions VI. On-Board Diagnostic Systems A. Vehicle Emission Control Information (VECI) Decal B. OBD-I (On-Board Diagnostic System, Generation 1) C. OBD-II (On-Board Diagnostic System, Generation 2) 1. Data Link Connector 2. OBD-II Terms 3. OBD-II for Light-Duty Diesels D. OBD-III (On-Board Diagnostic System, Generation 3) VII. System Operation A. Closed-Loop Mode B. Open-Loop Mode C. Fail-Safe or Limp-In Mode D. Adaptive Strategy VIII. OBD-II Monitoring Capabilities 1. Drive Cycle 2. OBD-II Trip 3. Warm-up Cycle A. Catalyst Efficiency Monitor B. Misfire Monitor 1. Type A Misfires 2. Type B Misfires 3. Type C Misfires C. Fuel System Monitoring D. Heated Oxygen Sensor Monitor E. EGR System Monitoring F. Evaporative (EVAP) Emission System Monitor 1. Enhanced EVAP Systems G. Secondary Air Injection (AIR) System Monitor H. Thermostat Monitor I. PCV Monitor J. Variable Cam Timing System Monitor K. Electronic Throttle Control System Monitor L. Comprehensive Component Monitor IX. OBD-II Self-Diagnostics A. MIL B. Diagnostic Trouble Codes C. Freeze-Frame Data D. Generic and Enhanced Data E. Generic Test Modes X. Basic Diagnosis of Electronic Engine Control Systems ©2016 Nelson Education Ltd.

4-27

Automotive Technology: A Systems Approach, 3Ce A. Logical Diagnosis B. Repair Information XI. Diagnosing OBD-I Systems A. Visual Inspection B. Unlocking Trouble Codes C. Retrieving Trouble Codes D. Using a Scan Tool XII. Diagnosing OBD-II Systems A. Troubleshooting OBD-II Systems B. Intermittent Faults C. Serial Data D. Using Mode $06 E. Repairing the System F. Using a Wireless Interface

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Engine performance diagnosis is a very advanced concept in the automotive repair industry. Attempt to simplify the concepts as much as possible. Use comparisons to older carbureted and distributor systems. Use the material from the first five sections of Chapter 31 to summarize how all of the systems are integrated and rely on one another to operate the vehicle efficiently. Use analogies like jigsaw puzzle pieces to help the students visualize.

SHOP ACTIVITIES AND CASE STUDIES CASE STUDIES 1. A customer brings in his late-model pickup truck with an OBD-II system and complains that the “Engine” light is flashing on and off. What should the technician suspect the problem is? What should she do first? 2. A 2012 Chrysler 300 was brought into the shop with a driveability problem. A scan tool is connected to the DLC and the DTC “P0108” is displayed on the scan tool. Using the appropriate service information, outline the steps that should be followed to determine the cause of the problem.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. When the engine is cold, most electronic engine controls go into open-loop mode. In this mode, the control loop is not a complete cycle and the computer does not react to feedback information from the oxygen sensors. Instead, the computer makes decisions based on preprogrammed information. During the closed-loop mode, the PCM receives and processes all information available. Sensor inputs are sent to the PCM; the PCM compares those values to its programs, it then sends commands to the output devices. The output devices adjust ignition timing, air-fuel ratio, and emission control operation. The resulting engine operation will result from the new inputs from the sensors. This continuous cycle of information is called a closed loop.

4-28

Automotive Technology: A Systems Approach, 3Ce 2. When making decisions, the PCM is constantly referring to three sources of information: the look-up tables, system strategy, and the input from sensors. The computer makes informed decisions by comparing information from these sources. 3. OBD-II standards define a warm-up cycle as the period from when the engine is started until the engine temperature has increased by at least 16°C (60°F) and has reached at least 88°C (160°F). 4. A trip is a partial drive cycle that includes all of the conditions (enable criteria) required for a particular monitor to run. To run a monitor, the vehicle must be driven at different speeds and conditions, similar to when performing a drive cycle. The OBD-II drive cycle is a defined set of operating conditions that must take place for all monitors to run and complete. 5. The misfire monitoring system uses a highly accurate crankshaft angle measurement to measure the crankshaft acceleration each time a cylinder fires. If a cylinder is contributing normal power, a specific crankshaft acceleration time occurs. When a cylinder misfires, the cylinder does not contribute to engine power, and crankshaft acceleration for that cylinder is slowed. 6. b. 2 consecutive drive cycles must occur to illuminate the MIL during a Type-B misfire. 7. c. The crankshaft position sensor is used for misfire monitoring. 8. c. When a two-trip fault is detected for the second time, a DTC is stored as a pending code. This is a false statement, it is a pending code after one trip. 9. c. The vehicle’s computer is not able to control its operating conditions. 10. c. Trouble codes and other temporary information is stored in random access memory (RAM). 11. b. The fuel injector is not part of the fuel delivery system. 12. c. 7 of the 16 pins are assigned by the OBD-II standards. 13. b. A vacuum leak may not be detected by the on-board computer 14. a. The evaporative emissions system (EVAP) uses a leak detection pump (LDP) to check for leaks in the system. 15. c. The purpose of the downstream O2 sensor is to monitor the catalytic converter efficiency. 16. a. Mode $06 data allows the technician to access various monitor diagnostic test results. 17. b. A CO code would indicate a fault in the chassis system and it would be an OBD-II standard fault code. 18. a. A type A misfire monitor examines the engine every 200 revolutions. 19. a. The computer does not react to oxygen sensor feedback information while in open loop. 20. a. If a catalytic converter is not reducing emissions properly, the technician will notice a voltage frequency increase in the downstream O2 sensor reading.

4-29

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 32 Detailed Diagnosis and Sensors CHAPTER OVERVIEW This chapter covers many aspects of creating a strategy and diagnosing input sensors, output controls, computer power, and ground circuits. It also discusses using a scan tool to assist with the diagnostics by controlling many of the actuators and output devices.

LEARNING OUTCOMES

• • • • • • • • • •

Perform a scan tester diagnosis on various vehicles. Conduct preliminary checks on an OBD-II system. Use a symptom chart to set up a strategic approach to troubleshooting a problem. Monitor the activity of OBD-II system components. Diagnose computer voltage supply and ground wires. Test and diagnose switch-type input sensors. Test and diagnose variable resistance-type input sensors. Test and diagnose generating-type input sensors. Test and diagnose output devices (actuators). Perform active tests of actuators using a scan tool.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Using Scan Tool Data A. Diagnostic System Checks B. Connecting the Scan Tool C. Quick Tests D. Parameter Identifications (PIDs) E. DTCs and Service Information F. Monitor Failures G. Freeze-Frame Data H. Mode $06 Data I. Visual Inspection II. Symptom-Based Diagnosis A. Common Symptoms III. Basic Testing A. Testing Sensors

4-30

Automotive Technology: A Systems Approach, 3Ce IV. Diagnosis of Computer Voltage Supply and Ground Wires A. Ground Circuits 1. Electrical Noise 2. Clamping Diodes V. Switches A. Testing Switches VI. Temperature Sensors A. Engine Coolant Temperature (ECT) Sensor B. Intake Air Temperature (IAT) Sensor C. Other Temperature Sensors D. Testing VII. Pressure Sensors A. Manifold Absolute Pressure (MAP) Sensor B. Testing an MAP C. Vapour Pressure Sensor (VPS) D. Other Pressure Sensors VIII. Mass Airflow (MAF) Sensors A. Testing an MAF Sensor IX. Oxygen Sensors (O2S) A. Heated-Oxygen Sensors 1. Zirconium Dioxide Oxygen (ZrO2) Sensors 2. Titanium Dioxide (TiO2) Sensors B. Air/Fuel Ratio (A/F) Sensor C. Checking Oxygen Sensors and Circuits 1. Identifying the Cause of O2S Contamination 2. Testing with a Scan Tool 3. Testing with a DMM 24 4. Testing with a Lab Scope C. Testing Air/Fuel Ratio (A/F) Sensors D. HO2S and A/F Sensor Repair X. Position Sensors A. Throttle Position (TP) Sensor 1. TP Sensors for Electronic Throttle Control B. Testing a TP Sensor C. EGR Valve Position Sensor D. Accelerator Pedal Position (APP) Sensor XI. Speed Sensors A. Vehicle Speed Sensor (VSS) B. Troubleshooting a VSS 1. Hall-Effect Sensors C. Other Speed Sensors XII. Position/Speed Sensors A. Crankshaft Position (CKP) Sensor 1. Checking a CKP 2. Replacing a CKP B. Camshaft Position (CMP) Sensor 1. CMP Sensor Service XIII. Knock Sensor (KS) A. Testing a Knock Sensor XIV. Computer Outputs and Actuators A. Electronic Throttle Control

4-31

Automotive Technology: A Systems Approach, 3Ce B. Testing Actuators C. Testing with a DMM D. Testing Actuators with a Lab Scope E. Testing with a Current Probe F. Repairing the System

ADDITIONAL TEACHING HINTS

• Demonstrate how disabled sensors will affect the system. • Induce sensor problems and have the students follow the service manual’s troubleshooting guides to test and diagnose the problems.

• •

Induce an intermittent connection problem on various sensors and demonstrate if OBD-II will capture the fault. Demonstrate test and diagnostic procedures using the scanner, DVOM, and lab scope.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Diagnosing computer controlled inputs and actuators can be a mystery unless the technician has an idea of what a good signal is. Have the students spend time retrieving signal from a variety of sensors and actuators and use chapter references of these sensors to determine a good versus a bad signal. Ensure that the students don’t fall under the same misconception that most customers do. That is, have them realize that the scan tool is just that, a tool not a magic box that will repair the vehicle just by connecting it to it.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using a lab scope and a software package designed to capture waveforms, look at the output of three different input sensors. Then store them in the software’s library. Finally, compare them to similar waveforms that already exist in the library. 2. Using a lab scope and a software package designed to capture waveforms, look at the action of three different actuators or output drivers. Then store them in the software’s library. Finally, compare them to similar waveforms that already exist in the library.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Three modes of operation for OBD-II are open-loop mode, closed-loop mode, and limp-home mode. 2. The four methods used to test individual components are to check visually, an ohmmeter, a voltmeter, a lab scope and a scan tool. In some cases, a final check can be made only by substitution. Substitution is not an allowable diagnostic method

4-32

Automotive Technology: A Systems Approach, 3Ce under the mandates of OBD-II, nor is it the most desirable way to diagnose problems. However, sometimes it is the only way to verify the cause of a problem. 3. True, a bad ground connection can cause an increase in the reference voltage to a sensor. 4. A typical normal oxygen sensor signal sent back to the computer will toggle between 0 and 1 volt indicating a rich or lean condition. 5. To adjust a TP sensor perform the following steps: 1. Back-probe the TP sensor signal wire and connect a voltmeter from this wire to ground. 2. Turn on the ignition switch and observe the voltmeter reading with the throttle in the idle position. 3. If the TP sensor does not provide the specified voltage, loosen the TP sensor mounting bolts and move the sensor housing until the specified voltage is indicated on the voltmeter. 4. Hold the sensor in this position and tighten the mounting bolts to the specified torque. 6. b. A faulty knock sensor (KS) would not likely cause a no-start condition 7. c. Verifying the customer complaint is typically always the first step in fault finding 8. b. If an engine coolant temperature sensor had a poor ground, this would produce an unwanted resistance. Because of this extra resistance, the voltage drop across the sensor would be less than 5 volts, so the values on the sensor signal seen at the PCM would be higher. 9. a. The most effective and most accurate device for testing computer inputs is the oscilloscope or lab scope. 10. b. A uniform AC signal would be generated by a magnetic pulse generator running at a constant rpm. 11. d. As rpm changes with a Hall-effect device the frequency of the signal will change. 12. a. A scan tool should always be used to extract codes on an OBDII system 13. c. A throttle position sensor’s waveform will rise smoothly on acceleration when testing with an oscilloscope. 14. b. A typical throttle position sensor failure is the signal voltage dropping out during operation. 15. b. An ideal number of cross counts of a HO2S in five 5 seconds at 2500 rpm is seven. 16. c. Transition time of a HO2S oxygen sensor is the time required to switch from lean to rich and rich to lean. 17. b. When applying vacuum to a MAP sensor the technician should see the signal voltage change. 18. a. An actuator is a device that the computer uses to perform mechanical work when a signal is sent to it. 19. d. Solenoids are most commonly used as actuators on computer-controlled engines. 20. a. When a solenoid circuit is opened there is a large voltage spike produced as the solenoids winding is de-energized.

4-33

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 33 Intake and Exhaust Systems CHAPTER OVERVIEW This chapter covers all of the recent advances in intake and exhaust systems. Among these are thermostatic air cleaners, catalytic converters, turbochargers, and superchargers. Inspection, diagnosis, and service of various components are discussed.

LEARNING OUTCOMES

• Describe how the engine creates vacuum and how vacuum is used to operate and control many automotive devices.

• Inspect and troubleshoot vacuum and air induction systems. • Explain the operation of the components in the air induction system, including ductwork, air cleaners/filters, and intake manifolds.

• • • • •

Explain the purpose and operation of a turbocharger. Inspect a turbocharger, and describe some common turbocharger problems. Explain supercharger operation, and identify common supercharger problems. Explain the operation of exhaust system components, including exhaust manifold; gaskets; exhaust pipe and seal; catalytic converter; muffler; resonator; tailpipe; and clamps, brackets, and hangers. Properly perform an exhaust system inspection, and service and replace exhaust system components.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Vacuum System A. Vacuum Basics B. Vacuum Controls C. Diagnosis and Troubleshooting D. Vacuum Test Equipment II. The Air Induction System A. Air Cleaner/Filter III. Induction Hoses A. Intake Manifold B. Design Variations C. Variable Intake Manifolds 1. Servicing an Intake Manifold IV. Forced Induction Systems

4-34

Automotive Technology: A Systems Approach, 3Ce A. Intercoolers V. Turbochargers A. Construction B. Turbo Lag C. Wastegate Valve D. Turbo Lubrication and Cooling E. Various Turbocharger Designs F. Twin Turbochargers G. DualBoost Single Sequential Turbocharger H. Turbocharger Inspection 1. Pressure Testing 2. Wastegates 3. Common Turbocharger Problems I. Replacing a Turbocharger J. Maintenance K. Turbo Start-up and Shutdown VI. Superchargers A. Supercharger Operation B. Supercharger Bypass System C. Supercharger Problems D. Maintenance E. Supercharger + Turbocharger VII. Exhaust System Components A. Exhaust Manifold B. Exhaust Pipe and Seal C. Catalytic Converters 1. Converter Problems D. Mufflers E. Resonator F. Tailpipe G. Heat Shields H. Clamps, Brackets, and Hangers VIII. Exhaust System Service A. Exhaust System Inspection 1. Exhaust Restriction Test B. Replacing Exhaust System Components 1. Exhaust Manifold and Exhaust Pipe Servicing 2. Replacing Leaking Gaskets and Seals 3. Replacing Exhaust Pipes

ADDITIONAL TEACHING HINTS

• •

Compare these manifold designs: open and closed intake, exhaust crossover, and EGR system.

Measure intake manifold vacuum on a live vehicle. Discuss the reason for the different readings obtained at different throttle openings. Show how things such as late ignition timing, an engine misfiring problem, or a restricted exhaust may be detected by using a vacuum gauge.

• •

Demonstrate testing exhaust back pressure. Explain why excessive back pressure is undesirable.

Demonstrate the use of a four-gas analyzer. Discuss the results and explain how they relate to intake, vacuum, and exhaust systems.

4-35

Automotive Technology: A Systems Approach, 3Ce

•

Show a turbocharger and discuss its operation and service. Discuss supercharger operation and service.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

A common misconception regarding forced induction components has been that bigger is better. Time should be spent refreshing the theory regarding air/fuel ratios to the students. The amount of fuel being delivered has to match the amount of air entering the engine for proper operation. Refer to the section at the beginning of Chapter 33 titled “Vacuum Basics” on page 985 for review. Remind students that regardless of how new and how many advanced technologies are being used to operate a vehicle they are working on, the basic theory of air and fuel in and exhaust gases out still applies.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On three vehicles of your choice, locate and identify the parts of the air induction system for a naturally aspirated, a turbocharged, and a supercharged engine and explain the purpose of each. 2. Raise the vehicle of your choice on a lift or hoist. Then locate and identify each part of the exhaust system. Take note of all components, including gaskets, clamps, and hangers. CASE STUDIES 3. A customer brings in her vehicle and complains of getting very poor gas mileage. What could be wrong with the vehicle’s intake and exhaust system that would cause this problem? 4. A customer brings his vehicle into the shop and complains of poor performance, especially during acceleration. The technician suspects that the catalytic converter is restricting the exhaust flow from the engine. Describe two tests that can be conducted to verify this condition.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Spray a soapy solution around suspected leaks on the pressure side of a turbocharger system to locate leaks. 2. Preheating the intake air improves fuel evaporation for cleaner burning and fewer emissions. 3. The purposes of an intake manifold are to (1) distribute the air/fuel mixture, (2) provide uniform quality air/fuel mixture, and (3) vaporize the fuel. 4. The effectiveness of a catalytic converter may be checked either by using a four-gas infrared analyzer, by measuring and comparing the inlet and outlet temperature, or by measuring exhaust back pressure. 5. A late-model vehicle has at least two catalytic converters in the exhaust system. 6. d. A miniconverter is sometimes referred to as a warm-up converter because it is used to clean up emissions during warm-up. 7. b. Intake manifold pressure controls the movement of the turbocharger wastegate in a non-computer controlled system.

4-36

Automotive Technology: A Systems Approach, 3Ce 8. a. Palladium is a catalyst in a catalytic converter. Palladium and platinum are both oxidizing catalysts. Oxygen combines with HC and CO when they contact heated palladium and platinum and form H2O and CO2. 9. d. Superchargers are not found in the exhaust system. Superchargers are gear driven by the engine. 10. c. Extremely rusted exhaust pipe connections make it necessary to use acetylene cutting torches for component removal. 11. c. At approximately 2000 rpm a typical turbocharger will begin to create boost. 12. d. The purpose of the intercooler is to cool the intake air to make it more dense. The denser the air, the more oxygen is available for combustion. 13. a. A turbocharger does not require engine horsepower to create boost. 14. a. The compressor wheel is the turbocharger component that is responsible for forcing air into the intake system. requires no mechanical connection between the compressor wheel and the engine. 15. a. Modern port fuel injected intake manifolds are commonly made of die-cast aluminum. Die-cast aluminum along with plastic is used for weight reduction. 16. a. The wastegate manages turbocharger output pressure. 17. c. Most turbochargers require at least 205 kPa (30 psi) of oil pressure for safe operation. Lack of lubrication is a major cause of turbocharger failures. 18. c. Start the engine and listen to the sound that the turbocharger makes to help diagnose any exhaust or boost pressure leaks. 19. d. A supercharger will improve horsepower and torque by pumping extra air into the engine in direct relationship to crankshaft speed. 20. b. Tuned exhaust headers prevent the exhaust flow from one cylinder to interfere with the exhaust flow from others.

4-37

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 34 Emission Control Systems CHAPTER OVERVIEW This chapter discusses the latest in emission control theory, components, and operation. It also covers pollutants, history of emission legislation, and development of emission control devices.

LEARNING OUTCOMES

• • • • • •

Explain how hydrocarbon (HC) emissions are released from an engine’s exhaust. Explain how carbon monoxide (CO) emissions are formed in the combustion chamber. Describe how oxides of nitrogen (NOx) are formed in the combustion chamber. Describe how carbon dioxide (CO2) is formed in the combustion chamber. Describe oxygen (O2) emissions in relation to air/fuel ratio Describe the operation of an evaporative control system during the canister purge and nonpurge modes.

• Explain the purpose of the positive crankcase ventilation (PCV) system. • Describe the operation of the knock sensor and electronic spark control module. • Describe the purpose and operation of an exhaust gas recirculation (EGR) valve. • Define the purpose of a catalytic converter. • Describe the operation of a secondary air injection system. • Describe the emission controls commonly found on today’s light-duty diesel engines. INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Pollutants A. Hydrocarbons B. Carbon Monoxide C. Nitrogen Oxides D. Carbon Dioxide 1. CO2 Reduction at Factories E. Oxygen F. Water (H2O) G. Diesel Emissions II. Emission Control Devices A. Legislative History B. Inspection and Maintenance Programs

4-38

Automotive Technology: A Systems Approach, 3Ce C. Vehicle Emission Control Information (VECI) 1. Engine/Evaporative Emission System Information 2. Base Engine Calibration Information D. Classifications of Emission Control Devices III. Evaporative Emission Control Systems A. Enhanced Evaporative Emission (EVAP) System IV. Pre-Combustion Systems A. Engine Design Changes B. PCV Systems 1. Operation C. PCV Valve 1. Heated PCV Systems D. EGR Systems 1. EGR Valve 2. Back-Pressure EGR 3. PCM-Controlled EGR Values 4. Electric Exhaust Gas Recirculation (EEGR) System E. Intake Heat Control Systems V. Post-Combustion Systems A. Catalytic Converters 1. Other Converter Designs B. Air Injection Systems 1. Electronic Secondary Air Systems VI. Diesel Emission Controls A. Low-Sulphur Fuel B. Diesel Fuel Injection C. PCV System 1. Crankcase Depression Regulator (CDR) D. EGR Systems E. Catalytic Converters F. Particulate Filter G. Selective Catalytic Reduction (SCR) Systems

ADDITIONAL TEACHING HINTS

• • • • •

Demonstrate oxygen (O2) emissions in relation to air/fuel ratio using a five-gas analyzer and propane enrichment. Demonstrate how oxides of nitrogen (NOx) are formed in the combustion chamber using a five-gas analyzer, disconnecting the EGR valve, and loading the engine. Demonstrate the operation of an evaporative control system by disconnecting the purge line and using an exhaust analyzer for HC at the port. Demonstrate how to check the positive crankcase ventilation system. Demonstrate the operation of an exhaust gas recirculation valve on a car, using a vacuum pump while the engine is running with a slight load.

4-39

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Due to the fact that the emissions being dealt with in this area can’t be seen, most technicians struggle with understanding their importance. Spend time discussing the effects on the environment and people if emission control systems are not functioning properly. Emphasize that manufacturers will not add components to vehicles if they serve no useful purpose. Have a discussion with the class identifying the emission control devices and the role they play in the proper operation of the vehicle. Use reference from the chapter under each of the gases and the components they are designed to control. Make sure to include the legal aspect of tampering with any of the control devices.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Use a service manual to identify the components of an exhaust gas recirculation system for a specific vehicle. Make a list of the components. Then locate the components on the vehicle and make a note of their location. 2. On an assigned vehicle, locate and identify the components of the PCV system. 3. Using an OBD II-equipped vehicle locate the components of an OBD-II advanced evaporative emission control system for a specific vehicle. Print out a description of the system operation. 4. Describe the required inspection and maintenance program for your province or locale. Include in your description the type of testing, the frequency of required testing, and the mandates for repair.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Gasoline engines must control emissions of HC, CO, and NOx. 2. Oxides of nitrogen (NOx) begin to form when temperatures in the combustion chamber reach 2,300°F (1,261°C). 3. The fuel storage and delivery system are also a source of HC emissions. 4. A catalyst is something that causes a chemical reaction without being part of the reaction. 5. c. The purpose of injecting secondary into the exhaust during warm-up is promote a quicker light-off of the O2 sensor and catalytic converter. 6. b. California has been instrumental in developing emission standards. 7. d. The PCV system prevents HC from escaping into the atmosphere. 8. a. The AIR system is responsible for controlling HC as well as CO. 9. a. Urea is the common name given to the fluid used in a selective catalytic reduction systems. 10. c. High combustion temperatures produce the formation of oxides of nitrogen (NOx). N and O2 in the air combine to form oxides of nitrogen. 11. b. Photochemical smog is a result of sunlight, NOx, and HC. When there is enough HC in the air, it reacts with the NOx. The energy of sunlight causes these two chemicals to react and form photochemical smog.

4-40

Automotive Technology: A Systems Approach, 3Ce 12. b. The EGR system is primarily responsible for the reduction of NOx and, when functioning properly, has little effect on overall engine performance. 13. c. In the catalytic converter HC and CO oxidizes to H2O and CO2 when they are exposed to heated surfaces covered with palladium and platinum. 14. d. The concern for CO2 emissions is one of the reasons that engineers are working hard to find alternate fuels for automobiles 15. b. An EGR cooler is used on modern diesel engines to reduce NOx emissions. 16. d. British Columbia with their Air Care program and Ontario with their Drive Clean program are the only two Canadian provinces with mandatory emission testing. 17. a. The PCV valve sends the crankcase vapours to the intake manifold to be burnt along with the air/fuel mixture. 18. c. Most EVAP systems will require that the vehicle is operating at a pre-determined temperature before allowing purge to take place. 19. c. The EGR valve operates when the engine is at various cruising speeds. 20. a. Carbon dioxide (CO2) contributes to greenhouse gases.

4-41

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 35 Emission Control System Diagnosis and Service CHAPTER OVERVIEW This chapter covers the testing, diagnosis, and repair of emission control system components.

LEARNING OUTCOMES

• • • • • • • • • • •

Use DTCs to help diagnose emissions problems. Briefly describe the emissions-related monitoring capabilities of an OBD-II system. Describe the reasons why certain gases are formed during combustion. Describe the inspection and replacement of PCV system parts. Diagnose engine performance problems caused by improper EGR operation. Diagnose and service the various types of EGR valves. Diagnose EGR vacuum regulator (EVR) solenoids. Diagnose and service the various intake heat control systems. Check the efficiency of a catalytic converter. Diagnose and service secondary air injection systems. Diagnose and service evaporative (EVAP) systems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. OBD II Test II. IM 240 Test A. Chassis Dynamometer B. Other I/M Testing Programs C. Interpreting the Results of an I/M Test III. Testing Emissions A. Exhaust Analyzer B. Interpreting the Results 1. General Guidelines IV. Basic Inspection A. OBD-II Monitors V. Evaporative Emission Control System Diagnosis and Service A. EVAP Monitors 1. Scan Tool B. Diagnosis

4-42

Automotive Technology: A Systems Approach, 3Ce C. Purge Test D. Leak Tests 1. Using Dye 2. Smoke Test 3. Fuel Cap Tester VI. PCV System Diagnosis and Service A. Consequences of a Faulty PCV System B. Visual Inspection C. Functional Checks of the PCV System D. Diesel Crankcase Ventilation Systems E. Measuring Crankcase Pressure VII. EGR System Diagnosis and Service A. Scan Tool B. EGR System Troubleshooting C. EGR Valves and Systems Testing D. Diagnosis of a Negative Back-Pressure EGR Valve E. Diagnosis of a Positive Back-Pressure EGR Valve F. Diagnosis of a Digital EGR Valve G. Linear EGR Valve Diagnosis H. Checking EGR Efficiency Hint: Show both a positive and a negative back pressure EGR valve. Allow the students to attempt to test them using a vacuum pump. Explain why this is not a conclusive test. Show digital and linear EGR valves and compare their merits. I. Electronic EGR Controls J. EGR Vacuum Regulator (EVR) Tests K. Exhaust Gas Temperature Sensor Diagnosis L. Diesel Engines VIII. Catalytic Converter Diagnosis A. Converter Diagnosis 1. Oxygen Storage Test 2. Checking Converter Efficiency Hint: Discuss ways to identify faulty catalytic converters. Describe the symptoms associated with a plugged converter. IX. Air System Diagnosis and Service A. Secondary AIR Monitor B. Secondary AIR System Service and Diagnosis C. Noise Diagnosis D. System Efficiency Test E. AIR Component Diagnosis 1. AIRB Solenoid and Valve 2. Combination Valve 3. Check Valve

ADDITIONAL TEACHING HINTS

• Demonstrate how to diagnose spark control systems. • Demonstrate engine performance problems caused by improper EGR operation (using a vacuum pump or screwdriver, hold the EGR valve open at idle). Demonstrate service procedures for the various types of EGR valves. ©2016 Nelson Education Ltd.

4-43

Automotive Technology: A Systems Approach, 3Ce

• Demonstrate EGR vacuum regulator (EVR) solenoid diagnosis. • Demonstrate how to diagnose and service the various intake heat control systems. Check the efficiency of a catalytic converter using a pyrometer, followed by a pre-cat test.

• •

Demonstrate how to diagnose and service secondary air injection systems. Demonstrate how to diagnose and service evaporative (EVAP) systems.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

• •

Because of the fact that we are dealing with chemical reactions that can’t be seen it may be difficult for students to fully understand how some of the control systems perform the jobs that they do. Attach an exhaust analyzer and create faults in some of the controls. Ask the students what the expected result should be and discuss the answers. Have the students use the section titled “Interpreting the Results” on page 1052 of Chapter 35 for help. Late model vehicle’s emission requirements are very stringent; ensure the students understand the impact of not following test and repair procedures completely.

SHOP ACTIVITIES AND CASE STUDIES CASE STUDY 1. The exhaust of a late-model vehicle with SFI is being analyzed. The technician finds the exhaust to have very high CO content at low speeds. At higher speeds, the CO decreases but is still higher than normal. What are the possible causes of the problem and what tests should be conducted to locate the problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A rich air/fuel ratio causes HC emissions to increase. 2. Too little EGR flow can cause overheating, detonation, and excess NOx. A reduction in EGR flow can be caused by an electronic fault, vacuum leaks, sticking valves, obstructions, or low vacuum. 3. A saturated charcoal canister can cause symptoms easily mistaken for other fuel system problems, like rough idle or flooding. 4. A PCV valve stuck in the open condition will allow excess air to flow through the valve, causing a leaner than normal air/fuel mixture. A rough idle or stalling may result from this mixture. 5. Because of the ability of OBD-II systems to monitor and report emission related failures, many provinces now use a check of the OBD-II system as part or all of their mandatory emissions testing program. A major advantage of using the OBD-II system is decreased costs since testing does not require the use of a dynamometer or gas analyzer. 6. d. The minimum efficiency of a functioning current model catalytic converter is 90% 7. a. Carbon monoxide is formed when there is not enough oxygen to combine with the carbon during combustion. 8. a. HC is measured in parts per million (ppm).

4-44

Automotive Technology: A Systems Approach, 3Ce 9. d. NOx is measured by a five-gas analyzer. 10. d. A restricted catalytic converter will not cause an increase in power at high speeds. 11. d. A vacuum leak in any of the evaporative emission components or hoses can cause starting and performance problems, as can any engine vacuum leak. 12. b. As a catalytic converter begins to deteriorate, the signal from the post-catalyst HO2S becomes more like the signal of the pre-catalyst HO2S. 13. d. During a typical EVAP pressure test 3.4 kPa (0.5 psi) of pressure is applied to the system. 14. b. O2 is not measured during an I/M 240 test. TheI/M 240 test does however measure HC, CO, NOx, and CO2. 15. a. A faulty AIRD valve or solenoid could cause a lean code as it will allow extra oxygen to pump into the exhaust before the O2 sensors. 16. d. Melted PFE/DPFE hoses would not be an indicator of a plugged or restricted catalytic converter. 17. b. HC and O2 would increase during a cylinder misfire as there would be both an excess of oxygen and raw fuel. 18. c. The minimum temperature that a catalytic converter could accurately be tested at is approximately 260°C (500°F). 19. b. An EGR valve that doesn’t open when commanded could cause pinging or detonation under heavy load. 20. b. Pressurized nitrogen pushing smoke through the system to check for leaks is the preferred method by most OEMs.

4-45

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 36 Hybrid Vehicles CHAPTER OVERVIEW This chapter discusses the theory, components, and operation of hybrid vehicles and their propulsion systems. Diagnosis of hybrid systems and the safety requirements involved are also examined.

LEARNING OUTCOMES

• • • • • • • • • • • •

Explain the differences between the different platforms for hybrid vehicles. List and explain the purpose of the basic components used in a power-split hybrid system. Explain how manufacturers provide four-wheel drive in hybrid SUVs. Describe the purpose of an inverter. Explain how the stop–start feature operates. Explain how regenerative brakes work. Describe the primary advantage of plug-in hybrid vehicles. Describe the operation of a flywheel alternator starter hybrid system. Explain how a belt alternator starter system works. Describe the basic operation of the hybrid system used in Honda’s IMA system. Describe the operation of the two-mode hybrid system.

List and describe the common-sense precautions that should be adhered to while working around or on a hybrid vehicle.

•

List the tools and equipment that are needed to safely diagnose, service and repair hybrid vehicles.

• • •

Describe how the high-voltage battery pack should be serviced. Describe what preventative maintenance procedures are unique to a hybrid vehicle. Explain the proper steps to take when diagnosing a problem in a typical hybrid vehicle.

4-46

Automotive Technology: A Systems Approach, 3Ce A. Batteries 1. Nickel-Metal Hydride (NiMH) 2. Lithium-Ion (Li-Ion) B. Motor/Generators C. Internal Combustion Engine D. Transmissions E. Stop–Start Feature F. Regenerative Brakes G. Control System H. Basic Systems 1. Belt Alternator Starter 2. Integrated Starter Alternator Damper (ISAD) 3. Power-Split System 4. Motors in Transmission 5. Electric 4WD I. Accessories J. HVAC K. Power Brakes L. Power-Steering M. GM’s Series Hybrids N. Powertrain O. Battery P. Basic Operation IV. GM’s Parallel Hybrids A. General Motor eAssist B. GM Two-Mode Hybrid System C. Operation V. Honda’s IMA System VI. IMA A. Electronic Controls B. Engine C. Transmission D. Acura Hybrids VII. Toyota’s Power-Split Hybrids 1. Other Hybrids from Toyota A. Battery B. Operation C. Electronic Controls 1. Battery ECU 2. Regenerative Braking D. Motors/Generators E. Power-Split Unit F. Prius Plug-In VIII. Ford Hybrids 1. Lincoln MKZ A. Operation B. Motors C. Controls D. Battery E. Engine/Transmission F. Cooling System

4-47

Automotive Technology: A Systems Approach, 3Ce G. 4WD IX. Porsche and Volkswagen Hybrids A. VW Jetta Hybrid X. Hyundai and Kia Hybrids 1. Kia Optima Hybrid XI. Nissan and Infiniti Hybrids XII. BMW Hybrids A. BMW i Concepts 1. i3 Concept 2. i8 Concept XIII. Mercedes-Benz Hybrids A. E400 Hybrid XIV. Maintenance and Service A. Safety Issues B. Precautions C. Gloves 1. Buffer Zone 2. Safety Hook D. Maintenance E. Batteries 1. Recharging 2. PHEV Charging Methods 3. Jump-Starting 4. Battery Cooling System Filter F. Diagnostics G. Test Equipment H. Air Conditioning

ADDITIONAL TEACHING HINTS

• •

Demonstrate the components of several hybrid vehicles and compare.

Lift a hybrid vehicle on a hoist and examine the chassis to identify the high voltage cabling from the battery to the engine bay.

•

Demonstrate the proper technique to disconnect the high voltage battery for service work.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Due to the fact that hybrid vehicles are still relatively new to the industry just about all aspects of the vehicle will challenge students. Be especially prudent when it comes to the safety aspects of working on or near the high voltage systems of any hybrid. As any of the hybrid vehicles listed in the chapter come into the shop have the students use the appropriate section and identify the components and the manufacturer’s safety recommendations for their system.

4-48

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Visit at least two automotive dealerships that sell hybrid vehicles or their websites and compare the power flows of their hybrid vehicles. In a short report, describe the differences and similarities. A look through the brochures will help you with this.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The basic components of a BAS system include the belt/alternator starter, a 42-volt battery pack, a drive belt, and a special tensioner. 2. A mild hybrid consumes less fuel than a conventional vehicle due to the start/stop feature as well as the small amount of assist the BAS gives the gasoline engine. 3. Always precisely follow the correct procedures. If a repair or service is done incorrectly, an electrical shock, fire, or explosion can result. Systems may have a high-voltage capacitor that must discharge after the high-voltage system has been isolated. Move the key and/or key fob a good distance away from the vehicle before starting any service. After removing a high-voltage cable, cover the terminal with vinyl electrical tape. When working on or near the high-voltage system, even when it is de-powered, always use insulated tools. Never leave tools or loose parts under the hood or close to the battery pack. These can easily cause a short. Never wear anything metallic, such as rings, necklaces, watches, and earrings, when working on a hybrid vehicle. Alert other technicians that you are working on the high-voltage systems with a warning sign such as “high voltage work: do not touch.” Keep in mind that the engine can start and stop on its own if it is left in the idle stop or READY mode—Make sure the READY light in the instrument panel is OFF. If the vehicle needs to be towed into the shop for repairs, make sure it is not towed on its drive wheels. Doing this will drive the generator(s) to work, which can overcharge the batteries and cause them to explode. Always tow these vehicles with the drive wheels off the ground or move them on a flat bed. In the case of a fire, use a Class ABC powder type extinguisher or very large quantities of water. 4. The Prius PHEV is based on the base Prius but is fitted with a 4.4 kWh lithium-ion battery pack. The pack allows the Prius to operate as a pure EV for longer distances and at higher speeds. The estimated all-electric range is 21 kilometres, which results in an expected total range of 765 kilometres. The car is also capable of driving up to 100 km/h while in the electric mode. The estimated fuel economy while operating as a gasoline-electric hybrid is 3.27 L/100km. 5. The inverter is a power converter that changes the high DC voltage of the battery to a 3-phase AC voltage for the electric motors. 6. a. An insulation resistance meter checks for voltage leakage from the insulation of the high-voltage cables. 7. b. The Chevrolet Volt is classified as a series hybrid. 8. d. The planetary carrier is attached to the engine output shaft. The sun gear is connected to MG1 and the ring gear is attached to MG2. 9. d. The minimum amount of time you should wait before beginning to work on or around the hybrid system after isolating the high voltage system is 5 minutes. 10. a. The insulated lineman’s gloves must be tested and recertified every 6 months. 11. a. The minimum safe distance or (buffer zone) around a hybrid vehicle is 1 metre.

4-49

Automotive Technology: A Systems Approach, 3Ce 12. b. The M/E cooling system cools the transaxle, motors, and the DC–DC converter. The system uses a PCM-controlled 12V coolant pump mounted near the bottom of the radiator to move the coolant through the system. 13. a. DTC P3009 indicates a short in the HV system. 14. d. Lighter and less-powerful engines are least likely to decrease fuel consumption of a hybrid vehicle. 15. b. The step up converter is used to supply power to the electric drive motors. 16. b. Approximately 30 percent of the normally lost braking energy is captured by the regenerative brake system. 17. d. A CAT III DMM must be used when working on a hybrid high-voltage system. 18. a. The BAS or belt alternator starter is mounted where the generator would normally be located. 19. b. The traditional 12V starter is used to start late model Honda hybrids during extremely cold weather. 20. c. The voltage rating of the lineman’s gloves used during powering and de-powering hybrids is 1000V.

4-50

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 37 Electric Vehicles CHAPTER OVERVIEW This chapter covers the systems and components involved in an electric vehicle. Also discussed are some of the safe servicing and diagnosing techniques used when working on an electric vehicle. An introduction to fuel cell technology is also included.

CHAPTER OVERVIEW

• List some of the advantages and disadvantages of owning an electric vehicle. • Describe the major systems that make up a BEV. • Describe the purpose and function of a battery control system. • Explain the differences between conductive and inductive battery charging. • Explain how most electric vehicles’ problems are diagnosed. • Describe some precautions that should be followed when troubleshooting and repairing an electric vehicle.

• Describe the basic configurations for the powertrain in a fuel cell vehicle. • Describe the major components of a fuel cell vehicle. • Explain how a fuel cell works. INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Introduction II. A Look at History III. Zero-Emissions Vehicles A. Advantages B. Cost C. Disadvantages IV. Major Parts A. Energy and Power B. Electric Motor C. Controller D. Inverter/Converter V. Battery Charging A. Charger to Vehicle Connectors 1. Inductive Charging

4-51

Automotive Technology: A Systems Approach, 3Ce 2. Conductive Charging B. Recharging Standards and Regulations 1. CHAdeMO Protocol C. Charging Precautions VI. Accessories A. HVAC B. Power Brakes C. Power-Steering VII. Driving an EV A. Starting B. Driving and Braking C. Maximizing Range VIII. Ford Focus IX. Nissan Leaf 1. Telematics 2. Pedestrian Sounds X. Mitsubishi i-MiEV XI. Tesla 1. Model S XII. Honda Fit EV XIII. Other Possibilities A. Mini E B. BMW ActiveE C. Toyota RAV4 EV 1. Scion IQ EV D. Smart ED E. Chevy Spark EV F. Subaru R1e Electric Car XIV. Basic Diagnosis A. Precautions B. Self-Diagnostics C. Reduced Range XV. Fuel Cell Vehicles A. Hydrogen B. The Practicality of FCEVs C. Hydrogen In-Vehicle Storage D. Reformers XVI. Fuel Cells A. FCEV Configurations B. Controls C. Temperature Concerns D. Fuel Cell Types E. Proton Exchange Membrane Fuel Cell F. Solid Oxide Fuel Cell G. Direct-Methanol Fuel Cell H. Alkaline Fuel Cell XVII. Prototype FCEVs A. Daimler B. General Motors Corporation C. Toyota D. Honda

4-52

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Due to the fact that both electric vehicles and fuel cell vehicles are still somewhat rare in the automotive industry there will be much curiosity associated with any and all aspects of the vehicle drive systems. Spend as much time as possible reviewing these vehicles if access can be gained and use the information contained throughout this chapter for discussion.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. If possible bring an electric vehicle into the shop and spend some time locating the components of the vehicle drive system. 2. Attempt to gain access to any fuel cell vehicle and spend time locating and discussing the components associated with its systems.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Carbon dioxide is a greenhouse gas and burning of carbon-based fuels since the industrial revolution has rapidly increased its concentration in the atmosphere, leading to global warming. 2. Things the driver of a BEV can do to extend the range include: Avoid high-speed driving. Maintain a moderate speed on highways. Avoid driving up inclines. Avoid frequent speed increases or decreases. Attempt to drive at a steady pace. Avoid unnecessary stopping and braking. Avoid full-throttle acceleration, accelerate slowly and smoothly. The vehicle should be well maintained, including proper tire inflation pressures. Unnecessary weight in the vehicle will shorten the driving range. 3. The major parts of the propulsion system in a BEV are a high-voltage battery pack, battery management system, the motor(s) and supporting system, 12-volt system, converter and/or inverter, and the driver’s displays and controls 4. There are three primary things that affect the required time to recharge the batteries: the current state of charge of the battery, the chemicals used in the cells of the battery, and the type of charger used. 5. Inductive charging transfers electricity from a charger to the vehicle using magnetic principles. With a conductive charger, a connector, safely makes the link between the power supply and the vehicle’s charge port. The connector makes a weatherproof direct electrical connection to the vehicle’s charge port. 6. c. Fossil fuels are a combination of carbon and hydrogen. 7. c. Carbon dioxide cannot be used as a source for the production of hydrogen. 8. d. In a fuel cell, catalysts are used to ignite the hydrogen; this causes a release of electrons or electrical energy. Is a false statement. 9. a. The basic fuel for a fuel cell is hydrogen. 10. d. A reformer changes the molecular structure of a hydrocarbon into a hydrogen gas. 11. b. Hydrogen does not have to be stored as a compressed gas. 12. b. SAE J1772 connector protocol allows for both AC and DC charging.

4-53

Automotive Technology: A Systems Approach, 3Ce 13. d. Energy is the ability to do work. 14. a. Water and heat are the only items found coming from a fuel cell electric vehicles’ exhaust. 15. c. Steam reforming is the most common way to produce hydrogen. 16. a. Gasoline can be used to create hydrogen. 17. b. Groupings of a fuel cell together are called fuel cell stacks. 18. c. The 12-volt lead-acid auxiliary battery is charged by a solar panel located on the rear spoiler. 19. b. The AC power inverter converts the battery’s DC voltage in three-phase AC to power the traction motor. 20. d. The purpose of the PEM in the fuel cell is to prevent the electrons from passing directly to the positive side of the fuel cell.

4-54

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 38 Clutches CHAPTER OVERVIEW This chapter describes in detail the design and operation of each part of a clutch. Considerable attention is given to clutch diagnosis and service.

LEARNING OUTCOMES • • • • • •

Describe the various clutch components and their functions. Name and explain the advantages of the different types of pressure plate assemblies. Name the different types of clutch linkages. List the safety precautions that should be followed during clutch servicing. Explain how to perform basic clutch maintenance. Name the most common problems that occur with clutches.

• Explain the basics of servicing a clutch assembly. INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Operation A. Torque Transfer B. Flywheel 1. Dual-Mass Flywheel C. Clutch Disc 1. Clutch Facings D. Retaining Plate E. Pressure-Plate Assembly 1. Coil-Spring Pressure Plate Assembly 2. Diaphragm-Spring Pressure Plate Assembly F. Pilot Bushing/Bearing G. Clutch Release Bearing 1. Constant-Running Release Bearing H. Clutch Fork I. Clutch Linkage 1. Shaft/Rod and Lever Linkage 2. Cable Linkage 3. Self-Adjusting Clutch 4. Hydraulic Clutch Linkage 5. Concentric Slave Cylinders 6. Clutch Pedal Switch

5-1

Automotive Technology: A Systems Approach, 3Ce Hint: Compare different styles of clutch components. Explain the function of the various features. Discuss the factors affecting clutch performance. II. Clutch Service Safety Precautions Hint: Emphasize the health risks associated with clutch service. Make sure the students understand the safety precautions. III. Clutch Maintenance A. Clutch Fluid Level B. Clutch Linkage Adjustment C. External Clutch Linkage Lubrication IV. Clutch Problem Diagnosis A. Slippage B. Drag and Binding C. Chatter D. Pedal Pulsation E. Vibration F. Noises G. Hydraulic Clutch Diagnosis Hint: Describe the common clutch problems and their probable causes. Explain how driving behaviour affects clutch longevity. V. Clutch Service A. Removing the Clutch 1. Flywheel Inspection 2. Flywheel Service B. Hydraulic Linkage Service 1. Replacing a Concentric Slave Cylinder 2. Bleeding the System 3. Gravity Bleeding

ADDITIONAL TEACHING HINTS • • •

Demonstrate how to adjust a cable or mechanical linkage clutch. Demonstrate how to remove and reinstall the clutch, T.O. bearing, pressure plate, and pilot bearing using an alignment tool, pilot bearing remover, and torque wrench. Demonstrate the proper way to handle older clutch materials containing asbestos.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Ensure the students fully understand all of the clutch components, their function and power flow through the clutch parts. This will help greatly with diagnosis of a clutch fault. Refer to the section entitled “Operation” on page 1154 of Chapter 38 and all subtitles listing the components. The different styles of clutch linkages can be somewhat confusing; spend time analyzing the different types by inspecting an example of each type. Refer to the section “Clutch Linkage” on page 1160 for reference while inspecting.

5-2

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using the service information system, locate and record the free play specification and then measure the clutch pedal free play on a vehicle equipped with cable linkage. 2. Using the service information system, locate and record the free play and clutch pedal height specifications and then measure the clutch pedal height and free play on a vehicle equipped with a hydraulic clutch system. 3. Using the service information system procedures, adjust the clutch pedal free play on a vehicle with cable clutch linkage. CASE STUDIES 4. A customer complains of clutch chatter in her 2013 Subaru Impreza WRX. Visual inspection does not indicate any loose or worn parts. Once the clutch disc is removed, the technician determines that oil is on the disc. What are possible locations of oil leaks that could penetrate the clutch disc? 5. The clutch pedal on a vehicle equipped with a hydraulic clutch system stays on the floor when it is depressed. List the checks that should be made before removing the clutch system. 6. A customer brings in his late-model car because of excessive transmission noise. This is the third time this year that the noise has appeared. The last two times, the technician found and replaced bad bearings in the transaxle. It is likely that this is the same problem again. What sort of clutch-related problem would cause premature transaxle bearing wear? What checks should be done to diagnose the problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Friction facings may be either (1) woven or (2) moulded. 2. True. If the fluid reservoir is low, check the entire system for leaks. 3. A diaphragm spring is sometimes also referred to as a Belleville spring. 4. Clutch linkages may be (1) shaft and lever, (2) hydraulic, or (3) cable. 5. A tape measure or ruler can be used to measure clutch pedal play. 6. b. The friction disc is splined to the transmission input shaft and rotates with it. 7. c. Torsional springs in the clutch disc absorb and dampen torque forces. 8. d. Spring pressure from the clutch pressure plate assembly provides the clamping force required to hold the clutch disc firmly between the pressure plate ring and the flywheel. 9. c. Brake fluid is used in a hydraulic clutch master cylinder. 10. a. The release bearing pushes against the pressure plate release fingers when the clutch pedal is depressed. 11. b. The clutch disc is the driven member of the clutch assembly. The clutch cover, pressure plate, and the flywheel are all drive members because they are directly connected to the engine crankshaft. 12. c. When the clutch is disengaged, power flow stops at the pressure plate and flywheel. There should be no contact between the drive members and the clutch disc.

5-3

Automotive Technology: A Systems Approach, 3Ce 13. d. A faulty pilot bearing would be the most noticeable when the vehicle is stopped at a red light. Pilot bearing noise can only be present when there is a speed difference between the crankshaft and the transmission input shaft. 14. c. Insufficient clutch pedal clearance results in premature release bearing failure. This would hold the release bearing in contact with the pressure plate release levers producing release bearing rotation at all times. 15. b. As the clutch disc wears, the clutch pedal free play decreases. As the disc wears, the pressure plate ring moves closer to the flywheel which forces the release levers to pivot closer to the release bearing, reducing the free travel or play. 16. a. Too much clutch pedal free play or travel can cause hard gear shifting or clashing. The clutch release mechanism may not be able to completely disengage the clutch, which would allow input shaft rotation when the clutch pedal is completely depressed. 17. c. The clutch disc wave or cushion springs are located between the two clutch facings. The springs allow for smooth clutch disc engagement. 18. b. The pressure plate is driven by the flywheel through the clutch cover. The flywheel is bolted to the engine crankshaft and the clutch cover is bolted to the flywheel. 19. c. The clutch disc cushion springs cushion the friction lining segment on clutch engagement. The cushion springs compress as the spring force from the pressure plate assembly applies force against the clutch disc allowing a gradual engagement. 20. c. The surface of the pressure plate ring contacts the clutch disc. The pressure plate ring is the drive surface that presses against the clutch disc and flywheel. Release bearing noise is most noticeable when the pedal is depressed and should stop when the pedal is released.

5-4

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 39 Manual Transmissions and Transaxles CHAPTER OVERVIEW Understanding the major parts of manual transmissions and transaxles is the key to being able to diagnose these units. The complexity of these parts and units is emphasized in this general discussion.

LEARNING OUTCOMES • • • • •

Explain the design characteristics of the gears used in manual transmissions and transaxles. Explain the fundamentals of torque multiplication and overdrive. Describe the purpose, design, and operation of synchronizer assemblies. Describe the purpose, design, and operation of internal and remote gearshift linkages. Explain the operation and power flows produced in typical manual transmissions and transaxles.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Transmission versus Transaxle A. Transmission Designs II. Gears A. Gear Design 1. Spur Gears 2. Helical Gears B. Idler Gears Hint: Show examples of spur and helical gears. III. Basic Gear Theory A. Transmission Gearsets B. Reverse Gear Ratios Hint: Calculate gear ratios through a mock-up transmission and then check the results in practice by shifting through the gears and counting revolutions of the input and output shaft. IV. Transmission/Transaxle Design A. Transmission Features B. Transaxle Features V. Synchronizers A. Synchronizer Design B. Operation ©2016 Nelson Education Ltd.

5-5

Automotive Technology: A Systems Approach, 3Ce C. Advanced Synchronizer Designs Hint: Show several common synchronizer designs. Show the areas where wear is most likely to be found. VI. Gearshift Mechanisms A. Gearshift Linkages VII. Transmission Power Flow A. Neutral B. First Gear C. Second Gear D. Third Gear E. Fourth Gear F. Fifth Gear G. Reverse Hint: Use a mock-up transmission to show power flow through each range. VIII. Transaxle Power Flows A. Neutral B. Forward Gears C. Reverse D. Differential Action Hint: Use a mock-up transaxle to show how power flows in each range. IX. Final Drive Gears and Overall Ratios Hint: Calculate final drive ratio and discuss how this affects the overall gear ratio and driveability factors such as acceleration, top road speed, and fuel economy. X. Dual-Clutch Transmissions A. Input from the Engine B. Operation C. Volkswagen/Audi Direct-Shift Gearbox (DSG) D. Ford’s PowerShift E. Porsche Dual Klutch (PDK) XI. Electrical Systems A. Reverse Lamp Switch B. Vehicle Speed Sensor C. Reverse Lockout System D. Shift Blocking

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

• •

There are a number of physics lessons in the study of manual transmissions/transaxles. Spending time understanding how a transmission/transaxle provides not only the gears for torque multiplication required for acceleration but also gears capable of providing an overdrive for fuel economy is a critical part of how a vehicle functions. Use the section titled “Basic Gear Theory” on page 1180 of Chapter 39 as a guideline for this principle. Manual transmissions/transaxles are ideal for helping today’s students understand some basic mechanical principles such as torque multiplication. Studying the workings of a manual transmission/transaxle will go a long way in helping them in their studies.

5-6

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On a vehicle of your choice, use a service information system to identify all of the bearings in the vehicle’s transmission or transaxle. List the location of each. For each bearing, determine the speed gear that would operate noisily if the bearing were bad. 2. On a vehicle of your choice, use a service information system to identify the location of the synchronizers in the vehicle’s transmission or transaxle. Name the parts of each assembly and describe the purpose and action of each. 3. Trace the powerflow of a five-speed manual transmission or transaxle. 4. Using service information for either a Volkswagen/Audi or BMW, record all components involved in the operation of a self-shifting manual transmission. If a vehicle is available with this option, locate all components on the vehicle and record their location.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Whether a vehicle uses a transmission or a transaxle depends on the type of drive system used, such as whether the differential gearing is included in the same assembly as the transmission, and the location of the drive wheels. 2. When output speed is decreased through a set of gears, torque is proportionally increased; the opposite is true when speed is increased. 3. True. 4. A final drive gear is a set of gears that provides an additional torque increase at the wheels. 5. Shift rails and shift forks are used to control the movement of the synchronizers, with each synchronizer being able to engage or disengage two gear ratios by selecting which gear is locked to the main shaft. 6. c. To obtain a torque increase in a standard transmission, the output must turn slower than the input. The torque increase is produced by the engine force from a smaller gear being placed on the teeth of a larger gear. The force is placed further from the axis on the larger gear. 7. b. Gear pitch refers to the number of gear teeth per given unit of measure, such as diameter. 8. c. 0.85:1 is an overdrive ratio. This indicates that the output is turning faster than the input because it only requires 0.85 turns of the input to turn the output 1 full turn. 9. a. Spur gears are noisier at higher speeds. 10. a. When a small gear is used to drive a larger gear the torque output will be increased. 11. a. With an idler gear, the drive and driven gears rotate in the same direction instead of in opposite directions, such as would be the case without an idler. 12. a. A synchronizer matches the speed of the mainshaft and the gear selected to be engaged.

5-7

Automotive Technology: A Systems Approach, 3Ce 13. d. The shift forks in a synchronized transmission control or move the synchronizer sleeve. This sleeve when engaged to a gear locks the gear to the synchronizer hub which is splined to the transmission mainshaft. 14. b. The ring gear is driven by the pinion gear. This produces the final drive ratio in a transaxle. 15. b. The shift interlock mechanism prevents two gears from engaging at the same time. The interlock mechanism is made up of a series of pins or balls that allow only one shift rail to move from the neutral position at one time. 16. c. Constant mesh or speed gears are mounted on bearings or bearing surfaces on the mainshaft. These gears must be free to revolve at different speeds than the mainshaft. 17. d. The highest numerical ratio produces the most torque increase. This ratio would mean the input would have to turn 11.12 turns to make the output turn once. 18. a. All gears in the transmission with constant mesh gearing would revolve when the transmission is in neutral with the engine running and the clutch engaged. In constant mesh transmissions only shift collars or synchronizer sleeves are moved to lock gears to shafts. All gears remain in a specific location. 19. d. When calculating the gear ratio for the reverse gear set, the driven gear must be divided by the drive gear. This is the same for all gear sets. The idler gear should not be considered during the calculation because it is both a driven and a drive gear and therefore would be cancelled out. 20. c. In a transmission, the clutch gear drives the countergear.

5-8

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 40 Manual Transmission/Transaxle Service CHAPTER OVERVIEW This chapter develops an understanding of the importance of transmission/transaxle lubrication. It focuses on maintenance, cleaning, and inspection guidelines, and typical disassembly and assembly procedures.

LEARNING OUTCOMES • • • • •

Perform a visual inspection of transmission/transaxle components for signs of damage or wear. Check transmission oil level correctly, detect signs of contaminated oil, and change oil as needed. Describe the steps taken to remove and install transmission/transaxles, including the equipment and safety precautions used. Identify common transmission problems and their probable causes and solutions. Describe the basic steps and precautions taken during transmission/transaxle disassembly, cleaning, inspection, and reassembly procedures.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Lubricant Check A. Dual-Clutch Transmission Maintenance B. Lubricant Leaks C. Fluid Changes Hint: Look up the type of lubricant used and the change interval for a variety of vehicles. Discuss why they are different. II. In-Vehicle Service A. Rear Oil Seal and Bushing Replacement B. Linkage Adjustment C. Backup Light Switch Service D. Speedometer Drive Gear Service III. Diagnosing Problems A. Visual Inspection B. Transmission Noise 1. Rough, Growling Noise 2. Clicking or Knocking Noise C. Gear Clash D. Hard Shifting E. Jumping Out of Gear ©2016 Nelson Education Ltd.

5-9

Automotive Technology: A Systems Approach, 3Ce F. Locked in Gear G. Shift Linkage Hint: Describe the common transmission-associated problems and their probable causes. Talk about how non-transmission problems may be falsely attributed to the transmission. IV. Transmission/Transaxle Removal A. RWD Vehicles B. FWD Vehicles V. Cleaning and Inspection A. Aluminum Case Repair VI. Disassembly and Reassembly of the Differential Case A. Shim Selection VII. Reassembly/Reinstallation of Transmission/Transaxle A. Installing the Transmission/Transaxle

ADDITIONAL TEACHING HINTS • Discuss and demonstrate precision measuring techniques such as determining runout, or measuring parts to see if they fall within specifications. • Have the students install and remove bearings using a bearing press. • Discuss the importance of replacing sets of gears rather than a single gear to prevent a new part from failing prematurely. • Emphasize neat and orderly work areas and using the technical literature to ensure parts are reassembled correctly.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

The most important aspect for students to grasp when manual transmission/transaxle diagnosis is being performed is to fully understand all of the components that are rotating or loaded in each gear, what bearings are loaded and which components aren’t rotating. Refer to the section entitled “Diagnosing Problems” on page 1207 of Chapter 40 as reference. Ensure that the students pay close attention to using proper tools and pullers when servicing internal components of a manual transmission/transaxle; damage can result if not performed properly.

SHOP ACTIVITIES AND CASE STUDIES CASE STUDIES 1. A customer complains that his manual transmission makes noise in every gear except “direct drive.” Using the service information, determine what could be the cause of this problem. 2. A technician is diagnosing a complaint that the manual transmission in a 2013 Jeep Wrangler jumps out of direct drive when decelerating. He has inspected and adjusted the linkage and transmission mounts. What could be other causes of this problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Shiny metallic particles in the oil indicate internal bearing or gear wear.

5-10

Automotive Technology: A Systems Approach, 3Ce 2. A visual inspection should include (1) checking for lubricant leaks, (2) inspecting the transmission mount, (3) checking the clutch and transmission linkage, (4) checking the transaxle drive axle boots for cracks, deterioration, and damage, and (5) inspecting the constant velocity joints. 3. Some noises that appear to be transmission related but are not, include improperly aligned engines, improperly torqued mounting bolts, damaged or missing rubber mounts, cracked brackets, and loose objects in the engine compartment. 4. Use a gear puller to remove gears, bearings, and synchronizer assemblies. 5. When removing or installing bearings using a press, the force should always be applied to the tight bearing race instead of the loose one. 6. d. Worn or broken detent springs could cause a transmission to jump out of gear. The detent spring places force on the detent balls to hold the shift rails in their selected position. 7. b. Worn or dulled blocker ring oil cutting grooves could allow a synchronizer to not slow or speed up a speed gear. The oil cutting grooves allow the blocker ring to cut through the oil on the face of the speed gear cone and contact the gear. 8. a. Damaged input shaft bearings would be the most likely cause. 9. d. A clicking noise is most likely caused by chipped or damaged gear teeth. 10. c. Insufficient lubrication usually results in seizure and gear lock-up. 11. b. Using the wrong lubricant causes hard shifting. 12. a. Worn or damaged output shaft bearings could cause a rough growling noise in a transmission/transaxle that is heard when operating in all gears. The output shaft is rotating when the transmission is operating in all gear ranges. 13. b. The correct procedure for removing a bearing from a transmission shaft would be to use a puller on the inner race. By placing the force on the inner race, no force is being transmitted through the bearing assembly. 14. c. Worn or damaged output shaft pilot roller bearings could cause a rough growling noise in a transmission/transaxle that is heard when operating in all gears except direct drive. These bearings are located between the input shaft and the output shaft front support. Direct drive is the only range that does not have any shaft speed difference between the input and output shaft. 15. d. All of the above. 16. d. Synchronizers can be reused when rebuilding a transmission provided they are not worn or damaged. 17. a. A worn synchronizer blocker ring could cause gear clashing when selecting a particular gear. If the blocker ring was worn it would not be able to grab the gears cone surface and slow down or speed up the gear for a smooth and noise free gear selection. 18. b. When replacing a backup light switch the transmission gear selector should be placed in reverse. Do not move the gear selector until the switch is reinstalled. 19. d. Chipped or broken gear teeth could cause a rhythmic knocking noise. The section of the gear with the broken teeth will make a knocking noise each time it rotates into mesh with a gear. The knocking may be more pronounced when the damaged gear is under load. 20. d. When inspecting a synchronizer blocker ring, no space between the blocker ring and speed gear dog teeth would mean replacement is required.

5-11

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 41 Drive Axles and Differentials CHAPTER OVERVIEW This chapter develops the understanding of drive axles and differentials using illustrations to identify the many parts of these complex units. Also included are drive axle and differential diagnosis and service.

LEARNING OUTCOMES • • • • • • • • • • • • •

Name and describe the components of a front-wheel-drive axle. Describe the operation of a front-wheel-drive axle. Diagnose problems in CV joints. Perform maintenance on CV joints. Explain the difference between CV joints and universal joints. Name and describe the components of a rear-wheel-drive axle. Describe the operation of a rear-wheel-drive axle. Explain the function and operation of a differential and drive axles. Describe the various drive axle designs including complete, integral carrier, removable carrier, and limited slip. Describe the three common types of driving axles. Explain the function of the main driving gears, drive pinion gear, and ring gear. Describe the operation of hunting, nonhunting, and partial nonhunting gears. Describe the different types of axle shafts and axle shaft bearings.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Front-Wheel-Drive (FWD) Axles II. Types of CV Joints A. Inboard and Outboard Joints B. Fixed and Plunge Joints C. Ball-Type Joints 1. Fixed Ball-Type CV Joints 2. Plunging Ball-Type Joints D. Tripod CV Joints 1. Tripod Plunging Joints 2. Fixed Tripod Joints Hint: Show examples of different types of CV joints. Disassemble several CV joints and show how they operate differently from a U-joint. III. Front-Wheel-Drive Applications A. Other Applications ©2016 Nelson Education Ltd.

5-12

Automotive Technology: A Systems Approach, 3Ce IV. CV Joint Service A. Diagnosis and Inspection B. Obtaining CV Repair Parts C. CV Joint Service Guidelines V. Rear-Wheel Driveshafts A. Slip Yoke B. Driveshaft and Yokes VI. Operation of U-Joints A. Speed Variations (Fluctuations) B. Phasing of Universal Joints C. Cancelling Angles Hint: Explain why phasing and U-joint cancelling angles are important. Describe the symptoms of incorrect installation. Show examples of early failure caused by incorrect service. VII. Types of U-Joints A. Single Universal Joints B. Double-Cardan Universal Joint VIII. Diagnosis of Driveshaft and U-Joint Problems A. Visual Inspection B. Noise and Vibration Diagnosis C. Driveshaft Runout D. Driveshaft Angles 1. Measuring the Angles 2. Adjusting the Angles E. Driveshaft Balance 1. Hose Clamp Method F. Maintenance IX. Final Drives and Drive Axles A. Final Drive Components B. Drive Axle Housing and Casing C. Differential Operation X. Limited-Slip Differentials A. Clutch-Based Units B. Gear-Based Units C. Limited Slip Differential Diagnostics XI. Axle Shafts A. Semi-Floating Axle Shafts B. Three-Quarter Floating Axle Shafts C. Full-Floating Axle Shafts D. Independently Suspended Axles E. Axle Shaft Bearings F. Wheel Studs XII. Servicing the Final Drive Assembly A. Basic Diagnosis B. Disassembly C. Assembly D. Maintenance XIII. Diagnosing Differential Noises A. Vibration Problems B. Driveline Fluid Leaks ©2016 Nelson Education Ltd.

5-13

Automotive Technology: A Systems Approach, 3Ce

ADDITIONAL TEACHING HINTS • • • • •

Discuss methods of isolating drive axles and differential gear noises. Make sure students know how to install oil seals and dust seals. Discuss ball bearing inspection and evaluation techniques. Demonstrate how to set up a differential for pinion gear depth, backlash, and gear patterns. Examine and discuss CV joints and U-joints.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • • •

Understanding the speed changes that occur during the rotation of a rear wheel driveshaft will be a stumbling block for most students. Refer to the section entitled “Operation of U-Joints” on page 1237 of Chapter 41 for reference material. Using an old style steering shaft with two small universal joints works well for demonstration purposes. Support the shaft at either end and increase the angles while you observe the speed changes throughout the rotation. Use a demonstration differential on a bench to assist the students to understand how a differential allows each wheel to turn independently and yet provide power to drive the vehicle down the road. Refer to the section entitled “Final Drives and Drive Axles” on page 1246 for reference.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: CASE STUDIES 1. A customer complains that her rear drive unit makes noise above 50 km/h (30 mph) while under load. When coasting, there is no noise. Using the service information system, determine what could be the cause. 2. A technician is setting up the ring-and-pinion tooth contact pattern. Under light load the pattern is centred between the flank and the face but favours the heel heavily. To correct this pattern, what should the technician do? 3. When setting the pinion depth on a General Motors 10-bolt 194-mm (7⅝-in.) rear drive unit, the technician finds a “–4” marked on the pinion gear. What does this number represent?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. CV joints may be classified by (1) position, (2) function, or (3) design. 2. An axle with a removable carrier resembles a banjo; sometimes its housing is called the banjo housing. 3. An axle that merely supports the weight of the vehicle and provides a mounting place for the wheels is called a dead axle, as compared to a driving axle, which is called a live axle. 4. A floating axle with only one bearing per wheel located outside of the axle housing is classified as a three-quarter floating axle. The axle shaft only supports 25 percent of the weight; the rest is supported by the axle housing. 5. Differential problems usually appear as either a noise or a leak. ©2016 Nelson Education Ltd.

5-14

Automotive Technology: A Systems Approach, 3Ce 6. c. A conventional rear-wheel-drive vehicle does not typically use constant velocity joints. U-joints are typically used because the drive shaft only works through one angle. 7. b. In front-wheel drivetrains, the CV joint nearest the transaxle is usually referred to as the inboard joint. 8. a. A plunge joint is a CV joint that is capable of moving in and out as well as operate at an angle. 9. b. The axle shafts are splined to the differential side gears inside the final drive. With the side gears in mesh with the differential pinions, individual axle speeds are obtainable. 10. a. A double-offset joint has greater plunge capacity and can operate at larger operating angles. 11. c. A cross groove joint is flatter than other plunge joint designs. 12. d. A road test is the best way to determine which CV joint is noisy. Operate the vehicle over a surface that will allow the shafts to spin at different operating angles and under different loads. 13. c. Worn differential case gears would cause a final drive noise that is heard only when cornering. During cornering is the only time that movement between these gears occur. 14. c. The yoke is used to connect two or more shafts together. 15. a. Semi-floating axle designs carry the weight and transmit torque to the wheel. 16. b. When performing a final drive gear tooth pattern inspection, decreasing the backlash between the ring and pinion gears would move the contact pattern away from the heel of the tooth. Moving the ring gear towards the drive pinion will move the pattern from the heel to the toe of the ring gear tooth. Moving the ring gear away will move the pattern more towards the heel. 17. b. An overhung mounted final drive pinion requires two bearings, an inner and an outer. 18. c. In a limited slip differential, the friction discs and clutch plates are located between the differential side gears and the differential case. Gear separating forces during acceleration applies force to the clutch assemblies applying more equal drive to both axle shafts. 19. d. Inside a differential during cornering, the differential pinions or spider gears rotate on the pinion shaft. This rotation allows for different axle shaft speeds which allows the inside wheel to travel a shorter distance than the outer wheel. 20. b. A hypoid final drive has the centreline of the drive pinion below the ring or crown gear centreline. This design allows for a lower body position and therefore a lower centre of gravity.

5-15

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 42 Automatic Transmissions and Transaxles CHAPTER OVERVIEW This chapter discusses automatic transmission and transaxle theory, components, and operation.

LEARNING OUTCOMES • • • • • • • • • • •

Explain the basic design and operation of standard and lock-up torque converters. Describe the design and operation of a simple planetary gearset and Simpson gear train. Name the major types of planetary gear controls used on automatic transmissions, and explain their basic operating principles. Describe the construction and operation of common Simpson gear train–based transmissions and transaxles. Describe the construction and operation of common Ravigneaux gear train–based transmissions. Describe the construction and operation of transaxles that use planetary gearsets in tandem. Describe the construction and operation of automatic transmissions that use helical gears in constant mesh. Describe the construction and operation of CVTs. Describe the design and operation of the hydraulic controls and valves used in modern transmissions and transaxles. Explain the role of the following components of the transmission control system: pressure regulator valve, throttle valve, governor assembly, manual valve, shift valves, and kickdown valve. Identify the various pressures in the transmission, state their purpose, and tell how they influence the operation of the transmission.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Torque Converter A. Design B. Components C. Basic Operation D. Types of Oil Flow E. Overrunning Clutch Hint: Use a cutaway converter to show the students its internal components. Demonstrate the stator overrunning clutch operation. Point out the path of the oil during vortex and rotary flow. Show how the torque converter clutch is applied and released. II. Lock-up Torque Converter A. Lock-up Piston Clutch ©2016 Nelson Education Ltd.

6-1

Automotive Technology: A Systems Approach, 3Ce III. Planetary Gears A. How Planetary Gears Work 1. Maximum Forward Reduction 2. Minimum Forward Reduction 3. Maximum Overdrive 4. Minimum Overdrive 5. Slow Reverse 6. Fast Reverse 7. Direct Drive 8. Neutral Operation Hint: Pass around a simple planetary gearset to help the students become more familiar with it. Practise producing the common ratios by manually manipulating the gears. IV. Compound Planetary Gearsets A. Simpson Gear Train B. Ravigneaux Gear Train C. Planetary Gearsets in Tandem D. Lepelletier System 1. Power Flow Hint: Display a Simpson, a Ravigneaux, and a tandem gearset. Students should be encouraged to disassemble and reassemble them until they are very familiar with them. V. Honda’s Nonplanetary-Based Transmission VI. Continuously Variable Transmissions (CVT) 1. CVT Controls A. Planetary Gear–Based CVTs B. Two-Mode Hybrid System VII. Planetary Gear Controls A. Transmission Bands B. Transmission Servos 1. Simple Servo 2. Compound Servo Hint: Display single- and double-wrapped styles of bands. VIII. Transmission Clutches A. One-Way Clutches Hint: Show a roller clutch and a sprag clutch and explain the difference. B. Multiple-Friction Disc Clutch and Brake Assemblies IX. Bearings, Bushings, and Thrust Washers X. Snap Rings XI. Gaskets and Seals A. Gaskets B. Seals C. Metal Sealing Rings D. Teflon Seals XII. Final Drives and Differentials XIII. Hydraulic System A. Hydraulic Principles B. Applications of Hydraulics in Transmissions C. Functions of ATF D. Reservoir E. Venting ©2016 Nelson Education Ltd.

6-2

Automotive Technology: A Systems Approach, 3Ce F. Transmission Coolers G. Valve Body 1. Check Ball Valve 2. Poppet Valve 3. Spool Valve H. Oil Pump I. Pressure Regulator Valve J. Governor Assembly XIV. Pressure Boosts A. MAP Sensor B. Kickdown Valve XV. Shift Quality A. Accumulators B. Shift Timing XVI. Gear Changes A. Park/Neutral B. Reverse C. Drive Range D. Automatic Downshifting E. Manual Low

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Automatic transmissions rely on many different parts and subsystems to operate. Students will have many misconceptions as to how an automatic transmission operates. Use a disassembled transmission/transaxle and break it into subsystems and explain each system individually and how they all tie together. Use the appropriate section from the chapter for each component or system for reference. Spend considerable time explaining the operation of the torque converter and concentrate on the fact that it is a fluid coupling and it relies on fluid flow to operate. Use a cutaway of a converter and the section titled “Torque Converter” on page 1270 of Chapter 42 to reinforce the theory. Also, use 2 house fans facing one another to help visualize the concept.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Find one late-model vehicle equipped with a CVT and, using service information, record the components used to operate the CVT. Compare and record the physical differences noticed between the CVT and a conventional transmission/transaxle.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Rotary flow of oil in the torque converter is the flow of oil around the circumference of the converter as it rotates around its axis. Rotary flow begins to occur when the speed of the turbine is near the speed of the impeller, or near coupling speed. Vortex flow is the flow of oil from the impeller to the turbine and back to the impeller, at a 90-degree angle to engine rotation. The oil from the turbine to the impeller is redirected by the stator

6-3

Automotive Technology: A Systems Approach, 3Ce during torque multiplication. Maximum vortex flow occurs during maximum torque multiplication and is described as spiraling its way around the converter. 2. The overrunning clutch is responsible for allowing the stator to rotate in only one direction. 3. When two planetary gearsets are used in tandem, there are two simple planetary units connected in series, as compared to a compound planetary gearset that shares components. 4. The four common configurations used as the final drives on FWD vehicles are the helical gear, planetary gear, bevel gear, and hypoid gear. 5. When the converter is not locked, fluid enters the converter and moves to the front side of the piston, keeping it away from the shell or cover. Fluid flow continues around the piston to the rear side and exits between the neck of the torque converter and the stator support shaft. During the lock-up mode, the switch valve moves and reverses the fluid path. This causes the fluid to move to the rear of the piston, pushing it forward to apply the clutch to the shell and allowing for lock-up. 6. d. To achieve a direct drive in a simple planetary gearset, two gearset members must be driven by the input shaft. When two members are rotating at the same speed, no rotation between gear members occur and the entire gearset rotates as one component. This is also known as a planetary lock-up. 7. c. When the carrier is the input, the planetary gearset produces overdrive. When the carrier is the input and the sun gear is held, a minimum (slow) overdrive is achieved. The carrier’s planet pinions are forced to rotate or walk around the stationary sun gears teeth. This walking action of the pinions forces the ring gear to rotate faster than the carrier to produce the overdrive. 8. a. When the carrier is held, the planetary gearset produces reverse. When one of the other members is inputted, its rotation turns the carrier’s planet pinions like reverse idler gears. This action forces the remaining member to rotate in the opposite direction. 9. b. The stators overrunning clutch holds the stator locked during vortex flow allowing the stator to redirect fluid back to the impeller in a helpful direction allowing for greater speed differences between the impeller and turbine. During rotary flow the force of fluid against the back of the stator fins unlocks the overrunning clutch allowing it to rotate with the impeller and turbine. 10. d. Throttle pressure can be used to increase transmission mainline pressure. A throttle pressure feed to the transmissions pressure regulator valve allows the regulator valve to be throttle pressure sensitive. Throttle pressure adds to the regulator valves resistance which increases the pressure from the regulator valve (mainline). 11. c. The opposing forces that act upon shift valves to force them to move to the up or downshift position is throttle and governor pressure. Throttle pressure allows the shift valve to resist upshifts and force downshifts. 12. b. The drive member of the torque converter is the impeller. The impeller is a series of fins that are connected to the rearward section of the torque converter shell. The torque converter is bolted to the engine flexplate/flywheel and rotates with the engine. 13. b. Maximum vortex flow is present in the torque converter during maximum torque multiplication. 14. b. In order for lockup to occur, the lockup solenoid must be energized and the switch valve must be held down by line pressure. 15. c. An input shaft–mounted multiple disc clutch is capable of driving a planetary gearset member in an automatic transmission. 16. d. Bushings are capable of controlling radial loads while axial loads are controlled by thrust washers in an automatic transmission. ©2016 Nelson Education Ltd.

6-4

Automotive Technology: A Systems Approach, 3Ce 17. d. The switch valve controls oil flow to and from the Chrysler piston-type lock-up clutch assembly. 18. a. A Simpson gearset uses two planetary gearsets with a common sun gear. With this gearset, whatever affects one sun gear will affect the sun gears of both gearsets. 19. a. Some CVTs use a flywheel and a start clutch in place of a regular torque converter. 20. b. The stator is the torque converter component responsible for torque multiplication.

6-5

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 43 Electronic Automatic Transmissions CHAPTER OVERVIEW This chapter provides a look inside the electronic automatic transmission. Subjects include operation, diagnosis, and repair of sensors and actuators responsible for the shifting of the transmission.

LEARNING OUTCOMES

• Explain the advantages of using electronic controls for transmission shifting. • Briefly describe what determines the shift characteristics of each selector lever position. • Identify the input and output devices in a typical electronic control system, and briefly describe the function of each.

• Diagnose electronic control systems, and determine needed repairs. • Conduct preliminary checks on the EAT systems, and determine needed repairs or service. • Perform converter clutch system tests, and determine needed repairs or service. • Inspect, test, and replace electrical/electronic sensors. • Inspect, test, bypass, and replace actuators. INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Transmission Control Module A. Inputs 1. On–Off Switches 2. Digital Transmission Range (TR) Sensor 3. Throttle Position (TP) Sensor 4. Mass Airflow (MAF) Sensor 5. Temperature Sensors 6. Engine Speed 7. Transmission Fluid Temperature (TFT) Sensor 8. Transmission Pressure Switches 9. Voltage-Generating Sensors B. Outputs 1. Shift Solenoids 2. Pressure Control Solenoids 3. TCC Solenoid C. Adaptive Controls ©2016 Nelson Education Ltd.

6-6

Automotive Technology: A Systems Approach, 3Ce D. Limp-In Mode E. Operational Modes F. Manual Shifting G. CVT Controls II. Hybrid Transmissions A. Honda Hybrid Models B. Toyota and Lexus Hybrids C. Ford Motor Company Hybrids D. Two-Mode Transmissions 1. Operation III. Basic EAT Testing A. Scan Tool Checks B. Preliminary EAT Checks C. Electronic Defaults D. Guidelines for Diagnosing EATs IV. Converter Clutch Control Diagnostics A. Engagement Quality V. Detailed Testing of Inputs A. Testing Switches B. Throttle Position (TP) Sensor C. Mass Airflow Sensor D. Temperature Sensors E. Speed Sensors VI. Detailed Testing of Actuators A. Testing Actuators with a Lab Scope B. Testing Actuators with an Ohmmeter

ADDITIONAL TEACHING HINTS • •

Technicians will be dealing with electronic automatic transmission/transaxles during servicing. They need to be familiar with the regular service procedures associated with EAT. Cover maintenance procedures and compare them to non-electronic automatic transmission procedures. Remove a valve body from an electronic transmission and examine the shift solenoids and other sensors attached to the valve body. Cover their diagnosis, testing, and replacement.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Like any of the other systems on a vehicle that are electronically controlled through a module the electronic transmission/transaxle relies heavily on electrical signals and proper sensor information. Review electronic controls and sensor signals with the students and remind them that like the engine, the transmission can only react to the information sent to its module. Review “Inputs” on page 1316 of Chapter 43 for reference. Show examples of scan tool bi-directional communication with the transmission, again recall the techniques used with the engine control module to control certain actuators within the transmission to aid in the understanding of the operation of the EAT.

6-7

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On three different late-model vehicles with electronically controlled transmissions, use the service information system to determine how many solenoids are involved in the operation of the transmission and state what each is doing when the transmission is operating in its different gear ranges. 2. Locate a modern automatic transmission–equipped vehicle and connect a scan tool. Locate and record all of the transmission data PIDs listed on the scan tool. Create a separate list of the sensors used by both the engine and transmission.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. If the TFT sensor fails or the TCM determines temperature signals are incorrect, the TCM will look at engine temperature to estimate the temperature of the ATF. 2. Pressure switches can be checked by applying air pressure to the part that would normally be exposed to fluid pressure. 3. The TCM may receive information from two different sources: directly from a sensor or through the CAN communication bus that connects all of the vehicle’s computer systems. Normal engine-related inputs are used by the TCM to determine the best shift points. Many of these inputs are available at the common data bus. 4. Common problems that affect shift timing and quality as well as the timing and quality of TCC engagement are incorrect battery voltage, a blown fuse, poor connections, a defective TP sensor or VSS, defective solenoids, crossed wires to the solenoids or sensors, corrosion at an electrical terminal, or faulty installation of an accessory. 5. Most late-model EATs have systems that allow the TCM to change transmission behavior based on the current condition of the transmission and engine, current operating conditions, and the habits of the driver. Adaptive learning provides consistent quality shifting and increases the durability of the transmission. 6. c. MAP is not a voltage generating sensor. A MAP sensor changes its signal back to the PCM based on engine vacuum (load). 7. c. A glitch in a waveform of a speed sensor would not normally be caused by a poorly mounted sensor. 8. a. MG1 is the component responsible for the operation of the CVT and the effective overall gear ratio. 9. c. A solenoid that would not electrically energize would not typically be caused by a plugged filter screen at the solenoid. 10. a. The electronic pressure control (EPC) solenoid replaces the conventional TV cable setup to provide changes in line pressure in response to engine running conditions and engine load. 11. c. The vehicle speed sensor serves the same function as the governor valve used to. 12. b. When a good shift solenoid is activated a quick sharp snapping sound will be heard. 13. b. When a MAF sensor fails or sends faulty signals, the engine runs roughly and tends to stall as soon as you put the transmission into gear.

6-8

Automotive Technology: A Systems Approach, 3Ce 14. b. When the BPP switch tells the PCM that the brakes are applied the TCC clutch is disengaged. 15. d. When the fluid is too cold, shifting is delayed to help warm the fluid. Fluid temperature is used, along with other inputs, to control TCC clutch engagement. When the fluid is cold, the TCM prevents TCC engagement until the fluid reaches a specific temperature. 16. c. You should always begin any transmission related diagnosis with a road test to verify the customer complaint. 17. d. Shift solenoids are controlled by supplying a ground inside the control module. 18. a. Typically the default gear in an EAT is the one that occurs when all of the shift solenoids are de-energized. 19. d. The TCM reads sensor information up to 140 times per second. 20. a. The reduction in engine torque during shifting allows for smooth gear changes.

6-9

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 44 Automatic Transmission and Transaxle Service CHAPTER OVERVIEW This chapter describes how to perform service and maintenance of automatic transmissions and transaxles. Diagnosis and the replacement of the necessary parts to restore service are included.

LEARNING OUTCOMES • • • • • • • •

Listen to the driver’s complaint, road-test the vehicle, and then determine the needed repairs. Diagnose unusual fluid usage, level, and condition problems. Replace automatic transmission fluid and filters. Diagnose noise and vibration problems. Diagnose hydraulic and vacuum control systems. Perform oil pressure tests, and determine needed repairs. Inspect and adjust external linkages. Describe the basic steps for overhauling a transmission.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Identification II. Diagnostics A. Fluid Check 1. Transmissions without a Dipstick B. Recommended Applications C. Fluid Changes D. Parking Pawl III. Visual Inspection A. Fluid Leaks B. Oil Pan C. Torque Converter D. Extension Housing E. Speed Sensor F. Electrical Connections G. Checking Transmission and Transaxle Mounts H. Transmission Cooler and Line Inspection IV. Road-Testing the Vehicle A. Diagnosis of Noise and Vibration Problems V. Checking the Torque Converter A. Checking the TCC ©2016 Nelson Education Ltd.

6-10

Automotive Technology: A Systems Approach, 3Ce

VI. VII.

VIII.

IX.

B. Stall Test C. TC-Related Cooler Problems Diagnosing Hydraulic and Vacuum Control Systems A. Pressure Tests Common Problems A. Valve Body B. Servo Assemblies C. Band Adjustment Linkages A. Transmission Range Switch B. Gear Selector Linkage Replacing, Rebuilding, and Installing a Transmission A. Inspecting the Torque Converter B. Summary of T/C Checks Transmission Overhaul A. Installation

ADDITIONAL TEACHING HINTS • • • • • •

• • •

Demonstrate how to reseal a leaky transmission using the pump seal, o-ring, gasket, tail shaft seal, and pan gasket on a removed transmission. Demonstrate how to properly install cooling lines. Demonstrate how to measure the pump for reuse. Many students will be working in general repair shops and will be handling components like automobile transmissions as one unit. All technicians, however, can expect at some time to repair leaky or broken hydraulic fittings. Have your students assemble fittings, hoses, and tubing, depending on what is available, so they can learn how to make proper cuts and flanges and how to select the proper hardware. In conjunction with the preceding exercise, you can have each student’s project start and end with a certain fitting, so that in the end they can all be connected together and put under fluid pressure. (This might give the students a sense of teamwork and show how important the individual’s contribution is to the group; it may also show how just one component can make an entire system fail.) Take the students through changing the filter in an automatic transmission. Stress work area cleanliness and proper gasket installation. Make sure the students can restore the automatic transmission fluid to its proper level. Demonstrate the procedure for protecting components and open lines from contamination while the system is open.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Diagnosing an automatic transmission can be confusing without the understanding of the operation of the various controls. Attach pressure gauges to a transmission and operate the vehicle in a variety of gear positions to observe the different pressures that are obtained for pressure testing during diagnostics. Monitor scan tool data while operating the transmission during the pressure test as well to see the various solenoids and switches that operate. Use the section titled “Diagnosing Hydraulic and Vacuum Control Systems” on page 1355 of Chapter 44 as reference.

6-11

Automotive Technology: A Systems Approach, 3Ce •

Simulate a customer complaint for a transmission shifting fault. Have the students work in groups to come up with a diagnostic strategy and compare each group’s findings. Have them refer to sections from the entire chapter for assistance.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Disassemble a used automatic transmission or transaxle using proper tools and procedures and look for the worn out or broken components. Make a list of the components you would replace and have the instructor check your findings. CASE STUDY 2. A customer with a late-model Toyota pickup complained that every time the transmission shifted into third gear the entire truck shook as the transmission slammed into third gear. Describe your approach for identifying the cause of this problem.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A low fluid level usually indicates an external fluid leak. 2. Transmission fluid with a milky appearance indicates that engine coolant is contaminating the transmission fluid from a faulty transmission cooler. 3. When there are gum or varnish deposits on the transmission dipstick, the transmission fluid needs to be changed. 4. Pressure switches can be tested by applying air pressure to the area of the switch that would normally be exposed to hydraulic pressure and checking the switch for leaks. 5. When servicing a valve body, ensure that each valve moves freely in its bore. If it does not move freely, clean the valve and the bore and retest. If the valve cannot be cleaned enough to move freely in its bore, it is usually replaced. 6. c. The typical maximum pressure drop between shifts is no more than 104 kPa (15 psi). 7. c. Dark particles found in automatic transmission fluid is an indication of worn friction discs or bands. 8. a. When a shudder occurs during engagement of the torque converter clutch, the problem is typically in the converter. Poor torque converter clutch apply pressure or the condition of the clutches friction material will cause the clutch to grab and slip when applied. 9. c. Check the transmission fluid level at operating temperature with the engine running. 10. b. When rebuilding a clutch pack, new clutch discs should be installed after being soaked in new automatic transmission fluid. This prevents clutch disc damage during initial start-up. 11. b. The most likely cause of a transmission vibration would be an unbalanced torque converter. If the vibration changes with changes in engine speed, generally the torque converter is at fault. 12. c. A scan tool should be connected to monitor transmission operation when road testing an electronic automatic transmission. 13. a. When there is slippage in only one transmission operating gear, a faulty clutch pack would be suspected. Any pump, governor, or throttle circuit related problem would tend to affect a number of gear selections. ©2016 Nelson Education Ltd.

6-12

Automotive Technology: A Systems Approach, 3Ce 14. d. A higher than specified engine rpm during a stall test would indicate a slipping clutch or band. This slippage would allow the engine to rev higher before positive drive or a stall-out condition could take place. 15. a. Fluid seeping through the transmission case best refers to porosity. 16. b. A sticking electronic pressure control (EPC) solenoid could cause a lower than specified oil pressure reading in all gears during high loads or engine rpm only in an electronically controlled automatic transmission. 17. d. The transmission fluid and filter should be changed whenever fluid oxidation or contamination is present. The fluid change should only be performed when the transmission is at operating temperature. 18. a. A slipping stator one-way clutch could cause lower than specified stall speed readings during a stall test. The slipping clutch can allow the fluid to strike the pump side of the impeller fins causing the fluid to congest which increases the fluid force against the turbine causing the lower stall speed. This action is similar to the operation of a fluid coupling. 19. d. When performing a pressure test, a 690 kPa (100 psi) gauge can be used to monitor the governor circuit. Many computer controlled solenoids are ground side switched; hydraulic pressure does not apply a solenoid. 20. c. A faulty vacuum modulator could cause delayed or no upshifts in a nonelectronically controlled transmission. A faulty modulator would act as if no vacuum was present at its vacuum port simulating a high throttle pressure condition.

6-13

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 45 Four- And All-Wheel Drive CHAPTER OVERVIEW This chapter presents a general explanation of the design and servicing of four- and all-wheeldrive systems. These systems are very popular and, therefore, the need for service and repair is increasing.

LEARNING OUTCOMES • • • • • • • •

Identify the advantages of four- and all-wheel drive. Name the major components of a conventional four-wheel-drive system. Name the components of a transfer case. State the difference between the transfer, open, and limited-slip differentials. State the major purpose of locking/unlocking hubs. Name the five shift lever positions on a typical four-wheel-drive vehicle. Understand the difference between four- and all-wheel drive. Know the purpose of a viscous clutch in all-wheel drive.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Types of Four-Wheel Drives A. Part-Time 4WD B. Shifting 1. FWD-Based Systems C. Full-Time 4WD D. Full-Time AWD E. Automatic AWD F. 4WD Hybrids II. 4WD Drivelines A. Transfer Case B. Power Transfer (Take-Off) Units C. Locking Hubs D. Interaxle (Centre) Differentials E. Viscous Clutch F. Haldex Clutch 1. Volkswagen 4MOTION III. Torque Vectoring A. Active Differential Systems 1. Torque Vectoring Systems by ZF 2. Mitsubishi S-AWC ©2016 Nelson Education Ltd.

6-14

Automotive Technology: A Systems Approach, 3Ce B. Passive AWD Control Systems C. AWD Control Braking Systems 1. Porsche Torque Vectoring (PTV) 2. FWD Torque Vectoring IV. Diagnosing Four-Wheel Drive and All-Wheel-Drive Systems A. Basic System Diagnosis 1. Component Testing 2. Shift-on-the-Fly Systems 3. On-Demand Systems 4. AWD Systems B. Axle Hub Diagnosis C. Wheel Bearings V. Servicing 4WD Vehicles A. Maintenance B. 4WD and AWD Tires C. Servicing the Transfer Case D. Front Axles and Hubs 1. Manual Locking Hub 2. Automatic Locking Hub E. Wheel Bearings

ADDITIONAL TEACHING HINTS • •

Discuss the advantages and disadvantages of limited slip differentials in 4/AWD systems. Examine and discuss locking/unlocking hubs.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Because of the many different systems used by the various manufacturers, there are a lot of misconceptions about the types of AWD or 4WD systems in use today. Have the students work in groups and using a variety of 4WD and AWD vehicles, make a report about their vehicle’s system and report to each of the other groups. Have the students calculate the overall gear ratio for a 4WD vehicle in each of the forward gears and include the transmission, transfer case (4WD Low range), and final drive gear ratios.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. For two late-model vehicles with four-wheel drive and from two different manufacturers, compare the operation and layout of the driveline. Include in your description the controls used by the driver. 2. Using a late-model AWD SUV or passenger car, locate the components involved in the AWD operation. Include in your report the operation of the powertrain control module in deciding the power split between the front and rear axles.

6-15

Automotive Technology: A Systems Approach, 3Ce 3. Using the service information system procedures, disassemble, clean, inspect, and reassemble an automatic locking hub. CASE STUDY 4. A customer complains that no torque is being delivered to the front axle when he shifts his New Process 246 transfer case into four-high or four-low positions. What can be the cause of the problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. All-wheel drive provides improved traction and handling. 2. A four-wheel drive has (1) a transfer case, (2) a front drive shaft, and (3) a front drive axle. 3. Basically part-time 4WD is designed to be used off-road. This system makes a mechanical connection between the front and rear drive shafts when the transfer case is shifted into 4WD. Full-time 4WD transfer cases transfer constant power to the front and rear axles and include a centre or interaxle differential between the front and rear output shafts. Full-time 4WD can also be called “anytime 4WD,” although this is not entirely a correct designation. 4. An interaxle differential dissipates driveline windup, allowing the front and rear axles to operate at different speeds. 5. The difference between manual and self-locking hubs is the driver had to get out and turn a lever or knob at the centre of each wheel to lock the axle to the wheel hub and self-locking used a drive clutch to lock the hubs automatically. 6. c. Tractive effort is the driving force exerted by the wheels against the road surface. 7. d. When the plates of a viscous clutch (coupling) rotate at different speeds, the plates shear, or cut through, the fluid. This action rapidly heats the fluid which makes it stiffen which makes it more difficult for the two plates to rotate at different speeds and a lock-up occurs. 8. a. When operating a four-wheel-drive SUV on slippery winter roads, the shifter should be placed in the four-wheel-drive high range position. 9. d. An all-wheel-drive passenger car uses a centre differential instead of a transfer case. These are useful in all-wheel-drive applications because driveline windup is eliminated while traction and handling are improved. 10. c. Viscous clutches are applied automatically by the silicone fluid. 11. d. Most four-wheel-drive vehicles will allow shifting from two-wheel-drive high range to four-wheel-drive high range while on-the-fly (in motion). 12. a. All-wheel-drive vehicles operate in continuous four-wheel-drive. The driver does not have the option to select two or four-wheel-drive. 13. d. The transfer clutch functions as an interaxle differential. 14. c. A computer-controlled duty cycle solenoid operates the transfer clutch. 15. b. The viscous clutch is replaced as a complete assembly. 16. d. The fluid in a viscous clutch stiffens as it becomes heated. 17. c. A transfer case equipped with an interaxle differential is used in a typical 4WD pickup truck to prevent driveline windup during turns. The interaxle differential allows for different front and rear driveline shaft speeds. 18. d. One of the main advantages of four-wheel drive is the improved traction for offroad driving. 19. b. The purpose of the viscous clutch is to improve traction and mobility in adverse driving conditions.

6-16

Automotive Technology: A Systems Approach, 3Ce 20. b. Four-wheel-drive low range will provide the greatest torque to the wheels. When four-wheel-drive low is selected, the transfer case selects an additional gear reduction which increases the overall vehicle gear ratio and the torque available to the wheels.

6-17

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 46 Tires and Wheels CHAPTER OVERVIEW This chapter explains the care and service of tires and wheels. Factors that affect the performance and longevity of the tires are also explained.

LEARNING OUTCOMES • • • • • • • • • • •

Describe basic wheel and hub design. Recognize the basic parts of a tubeless tire. Explain the tire ratings and designations in use today. Describe why certain factors affect tire performance, including inflation pressure, tire rotation, and tread wear. Remove and install a wheel and tire assembly. Dismount and remount a tire. Repair a damaged tire. Describe the differences between static balance and dynamic balance. Balance wheels both on and off a vehicle. Describe the three popular types of wheel hub bearings. Service tapered roller bearings.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Wheels II. Tires A. Tube and Tubeless Tires B. Types of Tire Construction C. Specialty Tires D. Run-Flat Tires 1. Self-Sealing 2. Self-Supporting 3. Auxiliary Supported Run-Flat Systems E. Tread Designs F. Spare Tires G. The Ratings and Designations H. Tire Size I. Other Information 1. Tread Wear 2. Traction 3. Temperature Resistance

7-1

Automotive Technology: A Systems Approach, 3Ce 4. Additional Ratings J. Maximum Cold Inflation and Load K. Tire Placard L. Tire Care 1. Inflation Pressure 2. Tire Rotation 3. Tread Wear M. Tire Pressure Monitor (TPM) 1. Warning System N. Testing a TPM System Hint: Describe how proper tire care increases the longevity of the tires. Explain why rotation is important. III. Tire Repair A. TPM Sensors B. Repair Methods 1. Plug Repair 2. Cold Patch Repair 3. Hot Patch Repair C. Installation of Tire/Wheel Assembly on the Vehicle D. Inflation 1. Nitrogen Tire Inflation IV. Tire/Wheel Runout A. Tire Pull V. Tire Replacement A. Replacing One Tire B. Replacing Two Tires C. Four-Wheel-Drive and All-Wheel-Drive Vehicles D. Changing Tire and/or Wheel Size 1. Plus Sizing 2. Additional Points 3. Calculating Tire Dimensions VI. Tire/Wheel Assembly Service A. Tire/Wheel Balance 1. Static Balance 2. Dynamic Balance B. Wheel Balancing 1. Road Force Measurements VII. Wheel Bearings A. Front Wheel Hubs B. Rear Hubs C. Wheel Bearing Grease Specification D. Bearing Troubleshooting

ADDITIONAL TEACHING HINTS

• • • •

Compare samples of several types of tire construction. Discuss tire/wheel runout. Discuss the importance of maintaining wheel offset when changing to sport wheels. Discuss the ratings in terms of performance and wear.

7-2

Automotive Technology: A Systems Approach, 3Ce

• •

Demonstrate how to properly rotate tires and torque the lug nuts. Discuss the limitations on spare tires.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

A common misconception of most students, especially younger students is changing the tires and wheels on their vehicles for cosmetic reasons. Most people don’t understand the complications of changing their tires and wheels to aftermarket brands. Use the section titled “Tires” on page 1398 of Chapter 46 and all of the subsections relating to tire construction and fitment. A very simple but very often overlooked maintenance item on virtually all vehicles is tire pressure. All new vehicles contain TPMS but older vehicles are not equipped with the system. Students need to understand all the aspects of an under or overinflated tire and the resulting failures associated with this lack of maintenance. Use the section titled “Tire Care” on page 1407 for more information.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Select two vehicles with different tire sizes and designs. Record all of the available information located on the sidewall of one of the tires on each vehicle. Decipher the information including size, speed rating, load rating, UTQG, and tire pressure. 2. Select one vehicle that is equipped with a tire pressure monitoring system. Locate and record the method used to reset the TPM system light after the inflation has been corrected. 3. Inspect several failed bearings for wear. Determine if bearing failure was due to brinelling, loose adjustment, too-tight adjustment, or lack of lubrication. 4. Dismount and mount four tires. CASE STUDY 5. A customer complains of a heavy vibration from the front of his rear-wheel-drive vehicle. The technician has checked the tire balance and all steering and suspension components. What should she check next?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Wheels are constructed either from stamped or pressed steel riveted or welded together or from die-cast or forged aluminum or magnesium alloy. 2. Dynamic balance is described as an equal distribution of weight on each side of the tire’s centreline. Static balance is an equal distribution of weight around the circumference of the tire. 3. The tire should be deflated prior to breaking both beads away from the wheel rim. With the dismounting tool of the tire machine in place, push the sidewall that is 180° away down into the rims drop centre section and rotate the tire machine to dismount the first bead. Pull up on the tire placing the second bead into the rim drop centre section and place the machine dismount tool under the second bead and rotate the

7-3

Automotive Technology: A Systems Approach, 3Ce machine again to remove the tire. To mount the tire, reverse the removal steps. A blast of air may have to be used (with the valve core removed) to seat the bead against the rim for inflation. 4. A tire may be repaired using a plug that is slightly larger than the size of the puncture. Some plugs are inserted from inside the tire and pulled through with an installation tool, while others may be installed using an installation tool without removing the tire from the wheel. The plug is cemented in place and the excess is trimmed off, with care being taken not to pull on the plug while trimming it. 5. Underinflation can increase the rolling resistance of a tire. This results in rapid tire wear, hard steering, squealing, and a decrease in fuel economy by as much as 10%. 6. d. The series of a tire describes its profile. 7. a. Belts are constructed of steel, nylon, or woven fibreglass fibres. 8. a. A bubble balancer checks the static balance of a tire. 9. c. A radial tires body cords are arranged at 90° to the bead or the tire’s centreline. 10. a. Due to the extra air pressure pushing outward on the tire carcass, an overinflated tire will be worn more in the centre of the tread. 11. d. Overloading, age, and improper maintenance are all major causes of wheel failure. 12. b. The aspect ratio of a tire is found by dividing the tires section height by the section width. 13. c. The primary reason for the grooves in tire tread is to allow water to run out from between the tire and the road. 14. b. The tire placard contains information about the tire. This label is usually located on the driver’s door jamb. 15. b. Lateral runout is described as a side-to-side wobble. 16. a. The rapid up-and-down movement of a wheel is called wheel tramp. 17. b. A tread puncture that is less than 6.35 mm (1/4 inch) in diameter is repairable. 18. b. When adjusting wheel bearings, usually 0.03 to 0.13 mm (0.001 to 0.005 in.) end play should be present. 19. c. The Uniform Tire Quality Grading (UTQG) system includes the tire’s tread wear capability, traction, and temperature resistance. The UTQG ratings are shown on the side-wall of the tire. 20. a. The section of the wheel that allows the tire to be easily removed and installed is called the drop centre.

7-4

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 47 Suspension Systems CHAPTER OVERVIEW This chapter describes various types of suspensions including torsion bar suspension, live-axle rear suspension, independent suspension, and electronically controlled suspension. Functions of the various parts and service requirements are discussed.

LEARNING OUTCOMES

• Name the different types of springs and how they operate. • Name the advantages of ball joint suspensions. • Explain the important differences between sprung and unsprung weight with regard to suspension control devices.

• Identify the functions of shock absorbers and struts and describe their basic construction. • Identify the components of a MacPherson strut system and describe its functions. • Identify the functions of bushings and stabilizers. • Perform a general front suspension inspection. • Check chassis height measurements to specifications. • Identify the three basic types of rear suspensions and know their effects on traction and tire wear.

• Identify the various types of springs, their functions, and their locations in the rear axle housing.

• Describe the advantages and operation of the three basic electronically controlled suspension systems: level control, adaptive, and active.

• Explain the function of electronic suspension components including air compressors, sensors, control modules, air shocks, electronic shock absorbers, and electronic struts.

• Explain the basic towing, lifting, jacking, and service precautions that must be followed when servicing air springs and other electronic suspension components.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Frames A. Conventional Frame Construction B. Unibody Construction II. Suspension System Components

7-5

Automotive Technology: A Systems Approach, 3Ce A. Springs 1. Coil Springs 2. Leaf Springs 3. Air Springs B. Torsion Bar Suspension System C. Shock Absorbers 1. Gas-Charged Shock Absorbers 2. Air Shock Systems 3. Shock Absorber Ratio III. MacPherson Strut Suspension Components A. Struts B. Strut Mounts 1. Spacer Bushing 2. Inner Plate 3. Centre Sleeve 4. Mount Diagnosis and Service C. Lower Suspension Components D. Springs IV. Independent Front Suspension A. Short-Long Arm Suspension 1. Wheel Spindle 2. Control Arms 3. Ball Joints 4. Other Front System Components B. Four-Link or Multilink Front Suspension C. Four-Wheel Drive Front Suspension V. Basic Front-Suspension Diagnosis A. Shock Absorber or Strut Bounce Test B. Excessive Body Roll C. Noises D. Chassis Height Specifications Hint: Explain how chassis height changes over time and how this affects handling and alignment. Explain how chassis height is restored. VI. Front-Suspension Component Servicing A. Coil Springs 1. Removing a Spring B. Torsion Bars C. Ball Joints 1. Typical Radial Check 2. Typical Axial Check 3. Inspection of Wear Indicators D. Replacing Ball Joints E. Control Arm Bushings F. Strut Rod Bushings G. Anti-Sway Bar Bushings H. Shock Absorbers I. MacPherson Strut Suspension VII. Rear Suspension Systems A. Live-Axle Rear Suspension Systems 1. Leaf Spring Live-Axle System 2. Coil Spring Live-Axle System

7-6

Automotive Technology: A Systems Approach, 3Ce 3. Live-Axle Suspension System Servicing B. Semi-Independent Rear Suspension Systems 1. Semi-Independent Suspension System Servicing C. Independent Rear Suspension Systems D. Multilink Rear Suspension E. Servicing Independent Suspension Systems 1. Servicing Rear Coil Spring 2. Servicing Rear Control Arms VIII. Electronically Controlled Suspensions Hint: Discuss the advantages gained with adaptive and active suspension systems. A. Adaptive Suspensions 1. System Components 2. Compressor 3. Sensors 4. Electronic Shock Absorbers 5. Electronic Struts 6. Computer Control Module 7. Electronic Levelling Control 8. Adjustable Pneumatic Suspension B. MagneRide IX. Servicing Electronic Suspension Components A. Diagnosis B. Vehicle Alignment X. Active Suspensions A. Chassis Lubrication

ADDITIONAL TEACHING HINTS

• • • •

Display and discuss several types of shock absorbers, including worn ones. Examine and discuss the components of a front strut. Perform a general front-suspension inspection using guidelines and the service manual. Replace ball joints on a vehicle.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Frame and suspension systems are often overlooked. They are the foundation of a vehicle and most students starting out in the trade don’t give this area of the vehicle a lot of attention. Emphasize the need for routine inspection. Use all of the sections of this chapter to create a list for inspection purposes. Hoist as many different vehicles with different types of suspension systems as possible and examine each type for comparisons. Use basic suspension type information in the chapter as reference.

7-7

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Have your instructor assign a front-wheel-drive car, a rear-wheel-drive car, a two-wheel-drive pickup or SUV, and a four-wheel-drive pickup or SUV. Raise the vehicles on a hoist and identify the type of suspension at the front and rear of each vehicle. 2. Using a vehicle equipped with an adaptive suspension system, locate and record all of the components used with this system.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A stabilizer bar is sometimes referred to as a sway bar. It stabilizes the suspension system by transferring the movement of one wheel over to the opposite wheel to create a more level ride. 2. Sprung weight consists of all of the weight of the vehicle supported by the suspension system. Unsprung weight includes undercar components such as the axles, control arms, and steering knuckles that are not supported by the springs. A low ratio of unsprung weight is desirable for better ride quality. 3. An air spring operates on the principle that as a bag filled with compressed air is compressed, pressure in the bag increases. Increasingly more force is required to accomplish additional compression of the bag. In this way, an air spring functions as a variable rate spring and replaces conventional springs. 4. A conventional shock absorber dampens suspension movement by operating on the principle of fluid displacement through an orifice. It is a velocity-sensitive hydraulic dampening device. The faster it moves, the more resistance it has to movement. Kinetic energy (energy of motion) is converted to heat and dissipated to the atmosphere. As the rod of the shock absorber is forced inward during the compression cycle, it helps control the vehicle’s sprung weight. During the extension cycle, when the rod is pulled outward, it controls the unsprung weight. A typical shock absorber is designed to have a higher ratio of resistance during its extension cycle. 5. An independent suspension system allows each wheel to move independently in response to inputs from the road surface, braking torque, and body motion without affecting the other wheels. 6. b. The core of any suspension system is the spring. 7. d. When the wheel moves downward from the frame it is called rebound. 8. c. The steering linkage and the tires are part of the unsprung weight; the engine is part of the sprung weight of the vehicle. 9. a. When the wheel hits a bump and moves upward, it is called jounce. 10. a. Load-carrying ball joints will have zero play until they begin to wear and are not replaced until they exceed the wear limits. Follower ball joints should be replaced when any perceptible play is found. 11. d. The most common shock absorber ratio used on passenger cars is 50/50. This shock absorber offers equal resistance on jounce and rebound. 12. c. The shock absorbers dampen or control the motion of the vehicle. 13. a. The vehicles coil springs support the weight of the vehicle.

7-8

Automotive Technology: A Systems Approach, 3Ce 14. d. A tension loaded–load carrying ball joint is used on the lower control arm of a SLA suspension when the coil spring is placed between the lower control arm and the frame and the control arm is beneath the knuckle. 15. c. Torsion bars are pre-stressed for specific sides of the vehicle. Torsion bars are identified with an “L” or an “R” and must never be installed on the incorrect side of the vehicle. 16. d. SLA suspension systems may use a single or a double control arm design. 17. b. An anti-roll bar is used to transfer suspension movement from one side to the other during cornering. By transferring wheel movement to the opposite wheel, sway or lean during cornering is reduced and a more level ride is produced. 18. a. When measuring a vehicles ride height, the fuel tank should be full. 19. a. The modified MacPherson strut rear suspension is very common in front-wheeldrive vehicles. 20. a. The adaptive suspension system can actually change the ride height during operation.

7-9

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 48 Steering Systems CHAPTER OVERVIEW This chapter discusses manual, power-, and four-wheel steering system theory, operation, and components in depth.

LEARNING OUTCOMES • • • • • • • • • • • • •

Describe the similarities and differences between parallelogram, worm and roller, and rack and pinion steering linkage systems. Identify the typical manual-steering system components and their functions. Identify basic types of steering linkage systems. Identify the components in a parallelogram steering linkage arrangement and describe the function of each. Identify the components in a manual rack and pinion steering arrangement and describe the function of each. Describe the function and operation of a manual-steering gearbox and the steering column. Identify the components of the various power steering systems. Describe the function and operation of the various power steering system designs. Describe the service to the various power steering designs. Perform general power steering system checks. Inspect and service steering linkage components. Inspect and service power steering pumps. Describe the common four-wheel steering systems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Manual-Steering Systems Hint: Have students give the correct name for common steering systems parts from looking at several vehicles or by the use of a parts identification board. A. Steering Linkage B. Parallelogram Steering Linkage 1. Pitman Arm 2. Idler Arm 3. Links 4. Tie Rods C. Cross-Steer and Haltenberger Linkages ©2016 Nelson Education Ltd.

7-10

Automotive Technology: A Systems Approach, 3Ce D. Rack and Pinion Steering Linkage 1. Rack 2. Pinion 3. Yoke Adjustment 4. Tie Rods E. Manual-Steering Gear 1. Worm and Roller Hint: Demonstrate the correct way to adjust gear lash. F. Steering Wheel and Column G. Steering Damper II. Power-Steering Systems A. Integral Piston System B. Power-Assisted Rack and Pinion System C. Components 1. Power-Steering Pump 2. Power-Steering Pump Drive Belts 3. Electric Power Steering 4. Flow Control and Pressure Relief Valves 5. Power-Steering Gearbox Hint: Demonstrate the correct way to adjust preload and gear lash. 6. Power-Assisted Rack and Pinion Steering 7. Power-Steering Hoses III. Variable-Effort (Electronically Controlled) Power-Steering Systems A. Magnasteer B. Active Steering C. General Service D. Electric/Electronic Rack and Pinion System E. Column-Mounted Power Assist F. Steer-By-Wire System IV. Steering System Diagnosis A. Common Complaints 1. Excessive Steering Wheel Play 2. Feedback 3. Hard Steering 4. Nibble 5. Pulling or Drifting 6. Shimmy 7. Sticking Steering or Poor Return 8. Wandering B. Diagnosing C. Power-Steering Fluid D. Noise Diagnosis E. Power-Steering Pressure Checks 1. Testing Systems with a Pressure Tester V. Visual Inspection Hint: Demonstrate a pre-alignment inspection. A. Power-Steering Pump Belt B. Electric Power-Steering Systems C. Pitman Arm D. Idler Arm E. Centre Link

7-11

Automotive Technology: A Systems Approach, 3Ce F. Tie-Rod Assembly G. Steering Damper H. Dry Park Check I. Turning Effort J. Tie-Rod Articulation Effort K. Rack and Pinion Steering VI. Steering System Servicing A. Steering Linkage B. Rack and Pinion Inner Tie Rods C. Steering Gear Adjustments D. Rack and Pinion Service E. Steering Columns F. Steering Wheels VII. Power-Steering System Servicing A. Flushing the System B. Bleeding the System C. Electric Power Steering Systems D. Hoses and Lines E. Power-Steering Pump 1. Power-Steering Pump Pulley Replacement 2. Remove and Replace the Flow Control Valve and End Cover 3. Remove and Replace the Pressure Relief Valve VIII. Four-Wheel Steering Systems A. Mechanical 4WS B. Hydraulic 4WS C. Electrohydraulic 4WS D. Quadrasteer E. Acura Precision All-Wheel Steer

ADDITIONAL TEACHING HINTS

• • • •

Display and discuss several types of steering components, including worn ones. Examine and discuss the components of a worm and roller steering system. Examine and discuss the components of a rack and pinion steering system. Demonstrate the dry park check method for checking steering systems.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Students need to realize that not only does the steering system control the direction of the vehicle but there are also numerous safety features included in the steering linkage, steering column and connecting components. Review “Steering System Servicing” on page 1499 of Chapter 48 as part of the discussion. Even though steering linkages and components are built very sturdy to handle the irregularities and the shocks to the system from the roads, inspection and adjustment of components is very sensitive to small changes and minute wear that can adversely affect handling. Use the section titled “Visual Inspection” on page 1494 for discussion on proper inspection techniques.

7-12

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. On a vehicle equipped with a parallelogram steering linkage, locate the following parts: centre link, pitman arm, tie rods, idler arm, and steering gear. 2. On a vehicle equipped with a rack and pinion steering linkage, locate the following parts: tie rods, bellows, inner socket assembly, and steering gear. 3. On a vehicle equipped with power steering, identify the type of system used and identify the components that make up the power-steering system. After you have located them, point them out to your instructor. 4. Using either a hybrid vehicle or a non-hybrid equipped with electric steering, locate and record the components used to provide electric power assist. Use caution if using a hybrid for this task.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. A parallelogram steering arrangement using either a recirculating ball or worm and roller steering gearbox uses a pitman arm to connect to the steering linkage. The pitman arm transfers motion from the steering gearbox to the linkage, causing the wheels to turn in the correct direction. A rack and pinion steering arrangement has a small pinion gear attached to the end of the steering column that moves a toothed rack attached directly to the tie rods. Movement of the pinion gear causes the rack to push and pull the tie rods and moves the wheels in the desired direction. 2. A power-steering hose transmits fluid under pressure from the pump to the steering gearbox. 3. An integral power-steering system consists of a power-steering pump and reservoir, power-steering pressure and return hoses, and a power-steering gear (gearbox). The power-steering gear contains a power piston and control valves to assist in turning the wheels in both directions. 4. The term gearbox ratio refers to the number of input turns required to produce one output turn. 5. All-wheel steering reduces the tendency of production-built cars to either oversteer or understeer, producing near neutral steering under varying road conditions. The advantages gained are increased stability, cornering, and manoeuvrability. 6. c. Power-steering hoses transmit fluid under pressure. 7. b. The power piston is part of the ball nut in an integral recirculating ball powersteering gear. 8. c. The torsion bar in the directional control valve (DCV) controls the amount of assist in most power-steering systems. The amount the steering wheel is turned in relation to the resistance against the wheels determines the amount of torsion bar twist and the amount of hydraulic assist sent to the steering gear. 9. b. Wormshaft bearing preload is the first steering gearbox adjustment made. 10. d. Hydraulic fluid pressure in the power steering system is the greatest during steering assist with the wheels held against the steering stops.

7-13

Automotive Technology: A Systems Approach, 3Ce 11. b. Full-sized rear-wheel-drive cars usually use a recirculating ball type of steering gear. 12. d. The bellows boot protects the rack from contamination. 13. a. During a power steering pressure test, a lower than specified reading when the gauge shut-off valve is closed could be caused by a worn power-steering pump. 14. d. A shimmy is more likely to be the result of looseness in the suspension or steering linkage. 15. b. The idler arm supports the right side of the centre link and keeps the centre link level, but it does not keep the steering system level. 16. b. Insufficient steering gear preload could cause a vehicle to wander. 17. b. In the integral power rack and pinion steering gear, the power piston is attached to the rack gear. 18. c. In a mechanical four-wheel steering system, the rear wheels will move counterphase when the steering wheel is turned past 230°. Counter-phase four-wheel steering is turning the rear wheels in an opposite direction to the front wheels, greatly reducing the vehicle turning circle. 19. a. Rack and pinion steering is lighter and has fewer components than parallelogram steering. 20. b. The steering linkage connects the steering column to the wheels.

7-14

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 49 Wheel Alignment CHAPTER OVERVIEW This chapter discusses the theory and importance of proper two- and four-wheel alignment. Alignment equipment and tools are described.

LEARNING OUTCOMES

• • • • • • • • • • • • •

Explain the benefits of accurate wheel alignment. Explain the importance of correct wheel alignment angles. Describe the different functions of camber and caster with regard to the vehicle’s suspension. Identify the purposes of steering axis inclination. Explain why toe is the most critical tire wear factor of all the alignment angles. Identify the purposes of turning radius or toe-out. Explain the condition known as tracking. Perform a pre-alignment inspection. Describe the various types of equipment that can be used to align the wheels of a vehicle. Describe how alignment angles can be changed on a vehicle. Understand the importance of rear-wheel alignment. Know the difference between two-wheel and four-wheel alignment procedures. Identify and understand steering sensor calibration requirements.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Alignment Function A. Types of Wheel Alignment B. Road Crown II. Alignment Geometry A. Caster Hint: Use a steering knuckle that has been removed to show the arc travelled by the end of the spindle when the wheels are turned by simulating both positive and negative caster. Also show how tipping the steering knuckle to provide positive camber places the load on the inboard area of the spindle. B. Camber C. Toe ©2016 Nelson Education Ltd.

7-15

Automotive Technology: A Systems Approach, 3Ce D. Thrust Line Alignment E. Steering Axis Inclination (SAI) 1. Included Angle 2. Scrub Radius F. Turning Radius (Ackerman’s Principle) G. Thrust Line H. Load Distribution III. Prealignment Inspection A. Ride Height B. Results of Poor Alignment IV. Wheel Alignment Equipment A. Alignment Machine Care B. Turning Radius Gauges C. Caster-Camber Gauge D. Optical Toe Gauges E. Trammel Bar Gauge F. Miscellaneous Tools V. Alignment Machines V. Adjusting Wheel Alignment A. Specifications B. Caster/Camber Adjustment 1. Adjusting for Road Crown C. Adjusting Caster and Camber 1. Shims 2. Eccentrics and Shims 3. Slotted Frame 4. Rotating Ball Joint and Washers 5. Ball Joint Stud Bushings B. MacPherson Suspension Adjustments C. Rear-Wheel Camber Adjustments D. Toe Adjustment 1. Rear Toe 2. Thrust Line E. Setback VI. Four-Wheel-Drive Vehicle Alignment A. Steering Angle Sensor Calibration

ADDITIONAL TEACHING HINTS

• • • • •

Demonstrate how to do a prealignment inspection. Demonstrate how to read tire wear in terms of alignment problems. Demonstrate how to adjust camber and caster. Demonstrate how to adjust front wheel toe-in. Demonstrate how to adjust camber, caster, and toe on rear wheels.

7-16

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

• •

Time needs to be spent showing students how sensitive wheel alignment machines have the capability of being. Most electronic alignment equipment can measure to an accuracy of 1/100 of a degree. Putting slight pressure on a tire while measuring alignment angles can change them. A proper pre-alignment inspection needs to be performed before an alignment to find any imperfections in the steering or suspension systems. Use the section titled “Prealignment Inspection” on page 1521 of Chapter 49 to reinforce the discussion. Demonstrate to the students how small changes in the ride of the vehicle can change how the vehicle would handle on the road. Do this by adding weight to one side of the vehicle or letting an amount of air pressure out of one tire or decreasing the tension on a torsion bar on one side of a vehicle. Record the before and after alignment angles and discuss why the changes occurred.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Identify and list all of the wheel alignment tools and wheel geometry measuring devices found in your shop. CASE STUDY 2. After servicing the suspension of the vehicle and then aligning it, the technician takes the vehicle out for a test drive. The vehicle tracks and handles well, but the steering wheel is not centred while driving straight. The steering wheel was properly centred with the wheels in a straight-ahead position in the shop. What could be causing this problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Positive camber is the angle represented by the tilt of either the front or rear wheels outward from true vertical as viewed from the front of the car. 2. Excessive negative camber causes the portion of the tread toward the centreline of the car to wear. 3. Excessive negative caster can cause wandering, unintentional weaving, and instability at higher speeds. 4. Toe is the distance comparison between the leading edge and trailing edge of the tires. If the leading edge distance is less than the trailing edge, there is toe-in; if it is greater, there is toe-out. 5. The difference between rear toe and the geometric centreline of the vehicle is called the thrust angle. The vehicle tends to travel in the direction of the thrust line rather than straight ahead. 6. a. Ackerman’s principle refers to the aiming of the steering knuckles steering arms to produce the geometry that allows the inner wheel on a turn to turn in a tighter radius than the outside wheel. 7. b. The top of the steering axis must be moved rearward to make the caster more positive. 8. d. To make the camber more positive, the steering axis must be moved outward. 9. c. SAI is the inward tilt of the steering axis. The angle is formed between true vertical and a line drawn between the steering pivot points as viewed from the front.

7-17

Automotive Technology: A Systems Approach, 3Ce 10. b. During a four-wheel alignment, the rear wheels should be adjusted first followed by the front wheels. Adjustments should be made in this order: (1) rear camber, (2) rear toe, (3) front caster, (4) front camber, and (5) front toe. 11. a. Toe will produce the most tire wear when out of adjustment. 12. d. Toe can be measured with a trammel bar gauge. A trammel bar is a mechanical measurement bar used to measure the front and rear distances between the front tire centrelines. 13. c. Once the alignment machine heads are mounted on the wheels, wheel runout compensation must be performed at all four wheels. This aligns the alignment heads to the spindles and not an imperfect wheel. 14. d. Centring the steering wheel is the first step in adjusting front wheel toe. Both wheels should be adjusted to the preferred specifications with the wheel centred. 15. b. When performing a front wheel alignment, caster is the first angle to be adjusted. After the caster is adjusted, camber then toe should be adjusted. 16. d. Unequal caster angles can cause a pull to the side with the least positive caster. 17. c. Incorrect toe settings can cause featheredged tire wear. This wear is caused by the scrubbing of the tires against the pavement as the vehicle moves forward. 18. d. Steering axis inclination is not adjusted during an alignment. When caster is correct so should SAI. 19. a. When adjusting a vehicle to counter the effects of road crown, the left front wheel should be adjusted with slightly less positive caster. 20. b. Camber and steering axis inclination are added together to form the included angle.

7-18

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 50 Brake Systems CHAPTER OVERVIEW This chapter explains the principles of friction. The operating principles of hydraulic brake systems are described, including power brakes and antilock brakes systems. General diagnostics, testing, and servicing of hydraulic brake systems are explained.

LEARNING OUTCOMES

• Explain the basic principles of braking, including kinetic and static friction, friction materials, application pressure, and heat dissipation. •

Describe the components of a hydraulic brake system and their operation, including brake lines and hoses, master cylinders, system control valves, and safety switches.

• • • •

Perform both manual and pressure bleeding of the hydraulic system. Briefly describe the operation of drum and disc brakes. Inspect and service hydraulic system components.

Describe the operation and components of both vacuum-assist and hydraulic-assist braking units.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Friction A. Factors Governing Braking 1. Pressure 2. Coefficient of Friction 3. Frictional Contact Surface 4. Heat Dissipation B. Brake Lining Friction Materials 1. Nonasbestos Organic 2. Metallic Linings 3. Semimetallic Linings 4. Synthetic Linings 5. Ceramic 6. Carbon-Metallic/Ceramic Hint: Show examples of different types of friction material and discuss their characteristics. II. Principles of Hydraulic Brake Systems A. Dual Braking Systems ©2016 Nelson Education Ltd.

8-1

Automotive Technology: A Systems Approach, 3Ce 1. Front/Rear Split System 2. Diagonally Split System III. Hydraulic Brake System Components A. Brake Fluid Hint: Discuss the properties of brake fluids. Caution the students about how easily some spilled brake fluid can damage a vehicle’s painted surfaces. B. Brake Pedal C. Master Cylinders IV. Master Cylinder Operation 1. Master Cylinder Ports A. Master Cylinder Components B. Split Hydraulic Systems C. Fast-Fill and Quick Take-Up Master Cylinders 1. Brakes Not Applied 2. Brakes Applied 3. Brakes Released D. Central-Valve Master Cylinders V. Hydraulic Tubes and Hoses A. Brake Line Tubing B. Fittings C. Brake Line Hoses VI. Hydraulic System Safety Switches and Valves A. Pressure Differential (Warning Light) Switches B. Metering and Proportioning Valves 1. Metering Valve 2. Proportioning Valve 3. Height-Sensing Proportioning Valve 4. Combination Valves Hint: Explain why metering and proportioning valves are necessary for balanced braking with disc/drum systems. Show examples of each type of valve and describe its function. C. Warning Lights 1. Failure Warning Lamp Switch 2. Master Cylinder Fluid Level Switch 3. Parking Brake Switch D. Stop Lamps VII. Drum and Disc Brake Assemblies A. Drum Brakes B. Disc Brakes VIII. Hydraulic System Service A. Brake Fluid Inspection B. Master Cylinder Inspection 1. Quick Take-Up Valve Checks C. Air Entrapment Test D. System Flushing 1. Brake Line Inspection 2. Brake Pedal Inspection 3. Master Cylinder Rebuilding E. Hydraulic System Bleeding 1. Bleeding Sequence 2. Manual Bleeding

8-2

Automotive Technology: A Systems Approach, 3Ce 3. Pressure Bleeding F. Power Brakes G. Vacuum-Assist Power Brakes 1. Operation 2. Servicing Vacuum-Assist Booster Units 3. Pressure Check 4. Pedal Travel 5. Vacuum Reading 6. Release Problems 7. Hard Pedal 8. Grabbing Brakes 9. Check of Internal Binding IX. Pushrod Adjustment A. Gauge Method B. Air Method X. Hydraulic Brake Boosters A. Operation B. Basic Operational Test C. Accumulator Test D. Noise Troubleshooting XI. Electric Parking Brakes

ADDITIONAL TEACHING HINTS

• • • •

Display and discuss fully metallic, semi-metallic, and non-asbestos brake lining friction materials. Display and discuss hydraulic tubes and hoses. Examine and discuss drum and disc brake assemblies. Demonstrate methods of pushrod adjustment.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

• •

There is a common misconception amongst vehicle owners as well as beginning technicians that performing a “brake job” means just replacing the brake pads and/or the brake shoes. Spend time ensuring that the students understand the importance of properly inspecting the brakes and ensuring all of the features and components are functioning properly. There is also a misconception regarding all of the components that are part of a brake system. There are numerous parts that are somewhat hidden from easy view and need to be included in a proper inspection. In both cases use the appropriate sections to examine the various components and their function.

8-3

Automotive Technology: A Systems Approach, 3Ce

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Locate three different vehicles in your shop. Locate and record the recommended service interval for flushing the brake system. Using test strips or an electronic moisture tester, test and record the moisture content of the brake fluid in the three vehicles. 2. Using two vehicles, one with disc/drum brakes and one with disc/disc brakes, locate and record the components of each brake system. Then list the components that are different between the vehicles and discuss with your instructor why there are differences. CASE STUDY 3. The brake pedal on a late-model Chevrolet goes to the floor while the vehicle is stopped at an intersection. The brake fluid level is correct. What could be the cause of this complaint?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. All vacuum-assisted units are similar in design. They generate application energy by opposing engine vacuum to atmospheric pressure. A piston and cylinder, flexible diaphragm, or bellows use this energy to provide braking assistance. All modern vacuum-assist units are vacuum-suspended systems. This means the diaphragm inside the unit is balanced using engine vacuum until the brake pedal is depressed. Applying the brake allows atmospheric pressure to unbalance the diaphragm and allows it to move generating application pressure. 2. Brake systems on late-model cars are dual-circuit designs using a tandem master cylinder that separates the system into two circuits. The piston in each circuit is responsible for applying the brakes for two of the wheels. This provides a safety factor so that when one circuit fails, the other circuit can continue to provide partial braking. 3. The two common types of power brake boosters are the vacuum-assist and the hydraulic-assist. The vacuum-assist unit uses engine vacuum to increase the force applied by the brake pedal to the master cylinder. The hydraulic-assist unit uses power developed by the power steering pump to increase the amount of pressure exerted against the master cylinder pistons. 4. The pressure differential valve reacts to a loss of pressure in one of the hydraulic circuits and causes the brake warning light to be illuminated. 5. The combination valve combines the functions of the metering, pressure differential, and proportioning valves into one assembly. The metering valve functions to delay application of the disc brakes until the drum brakes have sufficient pressure to also apply; the pressure differential valve functions to alert the driver of a loss of pressure in one of the brake circuits; the proportioning valve functions to limit unwanted rear wheel lock-up during forceful application of the brakes. 6. a. When the tires are not skidding along the road surface there is static friction. 7. c. Bleeding the hydraulic system involves removing air pockets from the system.

8-4

Automotive Technology: A Systems Approach, 3Ce 8. a. The master cylinder generates the hydraulic pressure used to apply the brakes. 9. a. Two people are required to perform the manual bleeding method. 10. c. The purpose of the white lines stamped along the length of brake hoses is to help prevent brake hose twisting during installation. These lines are called natural lay indicators. 11. b. The purpose of the proportioning valve is to provide balanced braking in a disc/drum brake system. The proportioning valve allows a proportioned hydraulic pressure to the rear drum brakes during heavy braking to prevent rear wheel lock-up. 12. c. Disc brakes require higher application pressure and are commonly used with a power brake booster. 13. a. The function of the compensating port is to allow the brake fluid in the system to operate at atmospheric pressure when the pedal is released. This allows the brake fluid to expand and contract with temperature changes. 14. b. In brake fluid, 3% moisture contamination is considered excessive. On average, brake fluid will absorb approximately 2% moisture contamination per year and should be changed at least every two years. 15. a. The metering valve is used to prevent the front disc brakes from applying before the rear drum brakes overcome return spring pressure and contact the drum. 16. d. Fluid pressure from the power-steering pump is the source of brake system boost when a hydraulic brake booster is used. 17. d. Using power-steering fluid in the brakes hydraulic system could cause swelling and deterioration of the internal brake system rubber components. 18. b. Pascal’s law calculations are used to find the answer to this question. Both metric and imperial calculations follow. Metric – Force ÷ Area = Pressure 100 kg ÷ 5 cm2 = 20 kg/cm2 Pressure × Area = Output force 20 kg/cm2 × 35 cm2 = 700 kg Imperial - Force ÷ Area = Pressure 220.5 lb ÷ 0.775 in2 = 284.52 psi Pressure × Area = Output force 284.52 psi × 5.425 in2 = 1543 lb 19. d. When the speed of the vehicle is doubled, the braking force required to stop the vehicle would need to be increased by four times. Inertia is a large factor when dealing with increased speed. When the weight is doubled the braking power must also be doubled. 20. d. A leaking diaphragm in a vacuum-assist booster would provide little or no assist, resulting in an extremely hard pedal.

8-5

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 51 Drum Brakes CHAPTER OVERVIEW This chapter describes the design and operation of drum brakes and identifies the major components used with drum brakes. It emphasizes service procedures such as road testing the brakes, drum brake inspection and drum refinishing, wheel cylinder inspection and service, and adjusting parking brakes.

LEARNING OUTCOMES

• Explain how drum brakes operate. • Identify the major components of a typical drum brake and describe their functions. • Explain the difference between duo-servo and non-servo drum brakes. • Perform a cleaning and inspection of a drum brake assembly. • Recognize conditions that adversely affect the performance of drums, shoes, linings, and related hardware.

• • •

Reassemble a drum brake after servicing. Explain how typical drum parking brakes operate. Adjust a typical drum parking brake.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Drum Brake Operation II. Drum Brake Components A. Wheel Cylinders B. Brake Shoes and Linings C. Mechanical Components 1. Shoe Return Springs 2. Shoe Hold-Downs 3. Shoe Anchors D. Drums III. Drum Brake Designs A. Duo-Servo Drum Brakes B. Automatically Adjusted Servo Brakes 1. Basic Cable 2. Cable with Overtravel Spring 3. Lever with Override

8-6

Automotive Technology: A Systems Approach, 3Ce 4. Lever and Pawl C. Nonservo Drum Brakes Hint: Compare shoes used with duo-servo and nonservo brakes. Point out the differences between primary and secondary shoes. Show the various types of self adjusters. D. Automatically Adjusted Nonservo Brakes 1. Automatic Cam Adjusters 2. Ratchet Automatic Adjuster E. Inspection and Service 1. Brake Noise IV. Road-Testing Brakes V. Drum Brake Inspection A. Drum Removal 1. Fixed Drums B. Drum Inspection 1. Scored Drum Surface 2. Bell-Mouthed Drum 3. Concave Drum 4. Convex Drum 5. Hard Spots on the Drum Hint: Show an example of a drum with hard spots. 6. Threaded Drum Surface 7. Heat Checks 8. Cracked Drum 9. Out-of-Round Drum C. Drum Measurements Hint: Demonstrate measuring brake drums. D. Drum Refinishing E. Cleaning Newly Refaced Drums F. Cleaning, Inspecting, and Lubricating Brake Parts VI. Brake Shoes and Linings A. Brake Shoe Replacement B. Selecting Replacement Linings B. Sizing New Linings C. Lining Adjustment D. Drum Shoe and Brake Installation VII. Wheel Cylinder Inspection and Servicing A. Inspecting and Replacing Wheel Cylinders VIII. Drum Parking Brakes A. Types of Parking Brake Systems IX. Integral Parking Brakes A. Adjusting and Replacing Parking Brakes 1. Testing

ADDITIONAL TEACHING HINTS

• •

Discuss the precautions for road-testing brakes.

Have students complete a pre-brake-job inspection checklist as they perform a routine brake inspection.

8-7

Automotive Technology: A Systems Approach, 3Ce

•

Demonstrate how to measure drum diameter and discuss the limits as indicated in the shop manual or on drum markings.

•

Demonstrate the differences between primary and secondary shoes and where each goes on the backing plate.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Drum brake service or overhaul will be a stumbling block for a number of students due to the large number of parts and the very specific locations for each. A common practice is to leave one side together for reference while the other side is being serviced. Use the section titled “Drum Brake Components” on page 1576 of Chapter 51 to aid with identification and location of drum brake parts. Ensure students realize the importance of proper measurements, cleanliness, and service procedures since the brakes are one of if not the most important safety system on a vehicle. Customers rely on their brakes working properly every time they step on the brake pedal.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Remove a duo-servo drum brake assembly from a vehicle. Examine the components of a duo-servo drum brake and locate the following: wheel cylinder, return springs, anchor pins, primary and secondary shoes, connecting springs, and adjusting screw assembly. Wear a respirator and safety goggles or glasses with side shields. 2. Remove a nonservo drum brake assembly from a vehicle. Examine and list the components of a nonservo brake. CASE STUDY 3. A vehicle has been pulling to the right when its brakes are being applied. Brake fluid seems to be down a little. The vehicle has drum brakes on both the front and rear. They have 80 000 km (50 000 mi.) on them. What could be the problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Linings are attached to brake shoes by riveting or bonding. 2. When the brake shoes contact the rotating drum in either direction of rotation, they tend to move with the drum until one shoe contacts the anchor. This adds the energy of the rotating drum to the hydraulic force pushing the shoes against their anchors. 3. Worn or damaged drums may be scored, bell-mouthed, concave, convex, heat checked, cracked, out-of-round, threaded, or have hard spots. 4. The wheel cylinder stops prevent the wheel cylinder pistons from travelling too far. If the pistons were allowed unlimited travel, a sudden loss of fluid could occur. 5. When the parking brake pedal is applied, the cables and equalizer pull on the levers attached to the secondary shoe. The rear brakes with parking brake struts move the shoes against the brake drums. The shoes are held in position until the parking brake is released. 6. c. The backing plate is the foundation for the brake shoes and associated hardware.

8-8

Automotive Technology: A Systems Approach, 3Ce 7. c. The trailing shoe of a leading-trailing brake assembly is applied by wheel cylinder hydraulic force only. The trailing shoe’s application is against drum rotation preventing self-energization. 8. d. The primary shoe is the first shoe from the wheel cylinder in the direction of forward wheel rotation. 9. a. Brake linings that are worn to within 0.79 mm (1/32 in.) of a rivet head must be replaced. 10. d. In the unapplied position, drum brake shoes are held against the anchor pin by the return springs. 11. b. Duo-servo brakes are also referred to as self-energizing. 12. c. The adjustment mechanism is usually installed on the secondary shoe. 13. c. The purpose of a wheel cylinder is to convert hydraulic pressure to mechanical force against the brake shoe. 14. a. External brake parts should be wet-cleaned using water or water-based cleaners. 15. d. A buildup of dust and dirt between the drum and the shoes can cause a scored drum. 16. d. The diameter stamped on the brake drum refers to the discard diameter. A drum should not be resurfaced to its discard dimension; leave about 0.762 mm (0.030 inch) for wear. 17. c. A convex shaped brake drum can be caused by excessive heat. The heat will allow the open edge of the drum to expand and distort. 18. c. The equalizer connects the two rear park brake cables to the main or front cable. The various designs of equalizers allow the front cable to pull evenly on both rear cables. 19. b. Any drums with out-of-roundness or taper measurements of more than 0.150 mm (0.006 in.) are unfit for service and machining or replacement is required. 20. a. Wheel cylinders do not require same axle replacement (on both sides) when performing drum brake servicing. Wheel cylinders should be replaced whenever piston seizure or signs of brake fluid leakage is evident.

8-9

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 52 Disc Brakes CHAPTER OVERVIEW This chapter is devoted to disc brake design and function. It emphasizes inspection and service of the disc brake components.

LEARNING OUTCOMES

• • • • • • • •

List the advantages of disc brakes. List disc brake components, and describe their functions. Explain the difference between the three types of calipers commonly used on disc brakes. Describe the two types of parking brake systems used with disc brakes. Describe the causes of common disc brake problems. Explain what precautions should be taken when servicing disc brake systems. Describe the general procedure involved in replacing disc brake pads. List and describe five typical disc brake rotor problems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Disc Brake Components and Their Functions A. Rotors 1. Fixed and Floating Rotors 2. Composite Rotors 3. Ceramic Rotors 4. Solid and Ventilated Rotors 5. Drilled versus Slotted Rotors B. Rotor Hubs and Wheel Bearings C. Caliper Assembly 1. Fixed Caliper Disc Brakes 2. Floating Caliper Disc Brakes 3. Sliding Caliper Disc Brakes 4. Electric Calipers Hint: Show examples of each type of caliper. Show the sliding surfaces

8-10

Automotive Technology: A Systems Approach, 3Ce that require attention while servicing the disc brakes. Compare steel and phenolic pistons. D. Brake Pad Assembly Hint: Compare several grades of brake pads and discuss how the type of pad used varies with the type of operating conditions such as stop-and-go driving, taxicab driving, and the like. 1. Disc Pad Wear Sensors II. Rear-Wheel Disc Brakes A. Rear Disc/Drum (Auxiliary Drum) Parking Brake B. Caliper-Actuated Parking Brakes III. Disc Brake Diagnosis A. Warning Lights B. Pulsating Pedal C. Spongy Pedal D. Hard Pedal E. Dragging Brakes F. Grabbing Brakes G. Noise H. Pulling IV. Service Guidlines V. General Caliper Inspection and Servicing Hint: Show some brake pads with irregular wear patterns to demonstrate the consequences of inadequate caliper service. A. Caliper Removal B. Brake Pad Removal C. Caliper Disassembly D. Loaded Calipers E. Caliper Reassembly F. Brake Pad Installation 1. Fixed Caliper Brake Pads 2. Sliding Caliper Brake Pads 3. Floating Caliper Brake Pads G. Rear Disc Brake Calipers VI. Rotor Inspection and Servicing A. Lateral Runout B. Thickness and Parallelism C. Additional Checks 1. Grooves and Scoring 2. Cracks 3. Bluing or Heat Checking 4. Rust D. Rotor Service E. Removing a Rotor F. Brake Lathes 1. Bench Lathes 2. On-Vehicle Brake Lathes G. Installing a Rotor

8-11

Automotive Technology: A Systems Approach, 3Ce

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

Ensure students are fully aware of the different types of disc brake pad wear patterns associated with disc brake caliper faults. Use the section titled “General Caliper Inspection and Servicing” on page 1613 of Chapter 52 as reference. A common mistake beginning technicians make is to use the incorrect torque setting for caliper versus caliper bracket bolts. The inexperience of young technicians won’t pick up on the wrong torque value and often caliper bolts will be broken off due to over torqueing.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. After removing the brake assembly, examine a front caliper and locate the following components: anchor plate, caliper housing, piston, dust boot, seal, inner shoe and lining, outer shoe and lining, antirattle spring, caliper support key, caliper support spring, and key retaining screw. Wear a respirator and safety goggles or glasses with side shields. 2. After removing the brake assembly, examine the rear caliper and locate the following components: boot, piston, seal, housing, and bleeder screw. Examine the parking brake mechanism and locate the following components (if applicable): thrust screw, antirotation pin, balls, operating shaft, thrust washer, end retainer, operating lever, and seals. Wear a respirator and safety goggles or glasses with side shields. CASE STUDY 3. A customer brings in her pickup with the complaint of constant brake dust buildup on the left front wheel. What are the possible causes of the problem and what needs to be done?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Disc brakes are (1) resistant to heat fade, (2) resistant to water fade, (3) perform better straight-line stops, and (4) automatically adjust as the pads wear. 2. The three major assemblies that make up a disc brake are (1) hub and rotor, (2) caliper, and (3) brake pads. 3. The three types of calipers used are fixed, sliding, and floating designs. 4. A rear disc/drum auxiliary parking brake uses the inside of the hub and rotor as a parking brake. 5. A caliper may contain one, two, or four pistons. 6. b. The square cut seal in the caliper returns the caliper piston away from the rotor during brake release. The seal distorts outward under application pressure and returns to its original shape on brake release bringing the piston back with it. 7. c. Ventilated rotors are used on larger vehicles. Ventilated rotors have two friction surfaces that are separated by fins that allow air between the surfaces that provide better heat dissipation. Stronger brakes require better heat dissipation. 8. d. The calipers square-cut seal allows the brake caliper to be self-adjusting. Pressure against the caliper piston will force the caliper out against the brake rotor. This force

8-12

Automotive Technology: A Systems Approach, 3Ce is great enough to force the piston through the seal while the seal is strong enough to retract the piston enough to allow free movement of the rotor past the brake pads. 9. c. The splash shield channels the flow of air over the rotor surface. 10. a. The audible wear sensor tab is located at the leading edge of the brake pad. 11. d. The dust boot prevents moisture from entering the cylinder bore. 12. a. A safe air pressure to use for removing the caliper piston is 207 kPa (30 psi). 13. d. The maximum brake pad taper allowed before replacement is required is 3.18 kPa (1/8 in.) from one end of the pad to the other. 14. c. A restricted brake hose could cause only the left disc brake assembly to drag. A restricted brake hose could prevent the fluid sent to the caliper from returning which would prevent the caliper piston from retracting. 15. c. Variation in rotor thickness is referred to as parallelism. 16. c. Hard spots on the rotor surface are the result of heat developed during braking. 17. d. A directional rotor must have its fins pointing rearward at the top of the rotor. This is done to allow centrifugal force to spin air outward from inside the rotor. 18. c. Excessive lateral runout is likely to cause a pulsating brake pedal. 19. b. When installing a piston into a caliper, clean brake fluid should be used as a lubricant. 20. a. A dial indicator is used to measure rotor lateral runout.

8-13

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 53 Antilock Brake, Traction Control, and Stability Control Systems CHAPTER OVERVIEW This chapter explains the different antilock braking systems. Also covered are the components, service, diagnosis, and repair of these systems, as well as traction and stability control.

LEARNING OUTCOMES

• •

Explain how antilock brake systems work to bring a vehicle to a controlled stop. Describe the differences between an integrated and a nonintegrated antilock brake system.

• Briefly describe the major components of a two-wheel antilock brake system. • Briefly describe the major components of a four-wheel antilock brake system. • Describe the operation of the major components of an antilock brake system. • Describe the operation of the major components of automatic traction and stability control systems.

• •

Explain the best procedure for finding ABS faults. List the precautions that should be followed whenever working on an antilock brake system.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Antilock Brakes A. Pressure Modulation B. Slip Rate C. Pedal Feel II. ABS Components A. Hydraulic Components 1. Accumulator 2. Antilock Hydraulic Control Valve Assembly 3. Booster Pump 4. Booster/Master Cylinder Assembly 5. Fluid Accumulators 6. Hydraulic Control Unit 7. Main Valve 8. Modulator Unit

8-14

Automotive Technology: A Systems Approach, 3Ce 9. Solenoid Valves 10. Valve Block Assembly 11. Wheel Circuit Valves B. Electrical/Electronic Components 1. ABS Control Module 2. Brake Pedal Sensor 3. Data Link Connector (DLC) 4. Diagnostic Trouble Code (DTC) 5. Indicator Lights 6. Lateral Acceleration Sensor 7. Pressure Switch 8. Pressure Differential Switch 9. Relays 10. Toothed Ring 11. Wheel-Speed Sensor Hint: Show some printouts of DTCs and describe how they are used by technicians. Pass around a variety of ABS electrical components. Point out which components would be associated with which DTCs. C. Multiplexing D. Basic Operation III. Types of Antilock Brake Systems Hint: Show examples of integral assemblies and nonintegral hydraulic modulators. Compare the differences in function. A. Two-Wheel Systems B. Full (Four-Wheel) Systems IV. ABS Operation A. Two-Wheel Systems (Nonintegral) B. Four-Wheel Systems (Nonintegral) 1. Operation 2. Modulator Assembly 3. Self-Diagnosis C. Four-Wheel Systems (Integral) D. General Motors’ Electromagnetic Antilock Brake Systems E. Other Brake System Controls V. Automatic Traction Control A. Engine Controls B. Driver Controls and Indicators VI. Automatic Stability Control A. Stability Control System Indicators VII. Antilock Brake System Service A. Safety Precautions B. Relieving Accumulator Pressure VIII. Diagnosis and Testing A. Prediagnostic Inspection 1. Warning Lamps B. Visual Inspection C. Test Drive D. Self-Diagnostics Hint: Assign the students to retrieve DTCs. E. Testers and Scanning Tools F. Testing Components with ABS Scan Tools

8-15

Automotive Technology: A Systems Approach, 3Ce G. Solenoid Leak Test H. Testing Components with a Lab Scope Hint: Demonstrate the wheel speed sensor voltage pattern on a lab scope. I. Component Replacement 1. Wheel Speed Sensor Service 2. Brake System Bleeding IX. Testing Traction and Stability Control Systems X. New Trends A. Electric Calipers B. Brake-by-Wire C. Electronic Wedge Brake (EWB) D. Wet Brakes E. Hold Feature

ADDITIONAL TEACHING HINTS

• • • • •

Point out the major components of a two-wheel antilock brake system. Point out the major components of a four-wheel antilock brake system. Describe the operation of the major components of automatic traction and stability control systems. Demonstrate how to find ABS faults using scanners and lab scopes. Demonstrate the precautions that should be followed whenever working on an ABS.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? • •

As with most systems controlled by a module, the ABS and Traction Control systems are diagnosed the same as any other module controlled system. A very important part of the diagnosis with ABS/TC is to know which system is on the vehicle. Any time there is an opportunity to look at lab scope patterns on a known good vehicle/sensor a technician or student should take advantage. There are a few different types of wheel speed sensors used on the various makes and models of vehicles. Use the section titled “Testing Components with a Lab Scope” on page 1656 of Chapter 53 and create a pattern library for yourself.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. On five different vehicles with ABS, use service information systems to determine the type of ABS system that is used on a particular vehicle. Include the number of wheel brake units that are controlled and the basic components used by the system. CASE STUDY 2. A customer brings in a vehicle with a flashing amber ABS light. What does this light indicate? Describe the procedure that should be followed to identify the cause of the problem.

8-16

Automotive Technology: A Systems Approach, 3Ce

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. Antilock brake systems may be classified as integrated or nonintegrated, by the level of control, and by which axles are controlled. 2. Automatic traction control is a system that applies the brakes of a drive wheel when it attempts to spin and lose traction. Automatic stability control systems correct oversteer and under-steer by applying one wheel brake to bring the vehicle back under control. 3. The wheel-speed sensor sends individual wheel-speed input to the ABS control unit. 4. An integrated system combines all of the components necessary to provide conventional hydraulic brakes, power assist, and antilock control into one assembly. With a nonintegrated system, the functions of conventional braking and power assist are provided by the conventional power brake components, while the function of antilock control is provided by the ABS. It may be considered an add-on system. 5. Diagnosis and testing of an ABS include (1) pre-diagnostic inspections and a test drive, (2) a warning light and symptom troubleshooting, (3) on-board self-diagnostics and code retrieval, and (4) individual component testing and trouble-code-based troubleshooting. 6. d. A one-channel antilock brake system can modulate pressure to both rear wheels at the same time to control skidding. Modulation is performed on the single or common brake line to the rear wheels. 7. a. A magnetic pulse type of wheel speed sensor produces a varying AC frequency. 8. a. When the inlet wheel circuit valve is open and the outlet valve is closed brake pressure can increase in the wheel cylinder or caliper. Normal non-antilock braking can occur when the valves are in this position. 9. b. Some antilock brake systems can modulate the pressure to the brakes up to 20 times per second. 10. a. When the amber antilock brake system light is constantly illuminated, no ABS operation will occur during braking. The amber ABS light should only illuminate during the self-check. When the light remains on, a malfunction is present. 11. c. On an ABS equipped vehicle, a pulsating brake pedal during heavy braking would indicate that the ABS is functioning correctly. The pulsations felt at the brake pedal are the result of the pressure modulation to the wheel cylinders or calipers. 12. b. An accumulator is usually charged with nitrogen gas. 13. b. DOT 3 brake fluid is recommended for most antilock brake systems. 14. a. A three channel antilock brake system is arranged with channels to the right front wheel, left front wheel and one to both rear wheels together. 15. c. When both wheel circuit valves are closed a pressure hold will occur at the affected wheel cylinder or caliper. The two closed valves will not allow any additional pressure in or any existing pressure out of the wheel cylinders or calipers. 16. b. The accumulator is a gas-filled pressure chamber attached to the pump and motor assembly. 17. b. When the automatic traction control system is operating, the brakes will be modulated on the spinning drive wheel. 18. d. The wheel speed sensors in a four-channel antilock brake system are located at all wheels. This system is capable of monitoring the speed of each wheel and modulating the pressure to each wheel. 19. c. Before removing a high pressure accumulator-equipped master cylinder on an ABS-equipped vehicle, the brake pedal should be pumped 25 to 50 times with the key off to ensure that the system pressure is relieved. 20. d. A brass feeler gauge should be used to measure a wheel-speed sensor gap.

8-17

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 54 Heating and Air Conditioning CHAPTER OVERVIEW This chapter explains heating, ventilating, and air-conditioning theory, components, and operation. The use of non-CFC refrigerants is stressed, and interchange concerns are explained.

LEARNING OUTCOMES • • • • • • • • •

Identify the purpose of a ventilation system. Identify the common parts of a heating system. Compare the vacuum and mechanical controls of a heating system. Diagnose temperature control problems in the heater/ventilation system. Remove, inspect, and reinstall the heater control valve(s) and heater core. Describe how an automotive air-conditioning system operates. Describe how refrigerants are used in the air conditioning system. Locate, identify, and describe the function of the various air-conditioning components. Describe the operation of the types of air-conditioning control systems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Ventilation System II. Automotive Heating Systems A. Heater Core B. Heater Control Valve 1. Systems Without a Control Valve 2. PTC Heaters C. Blower Motor D. Heater and Defroster Duct Hoses 1. Recirc/Fresh Mode E. Heaters and A/C Systems in Hybrid Vehicles III. Heating System Service A. Basic Heater Inspection and Checks B. Heater Core Service 1. PTC Heaters C. Heater Control Valve Service 1. Thermostat Service 2. Blower Motor Service D. Heater and Defroster Duct Service

9-1

Automotive Technology: A Systems Approach, 3Ce IV. Theory of Automotive Air Conditioning A. Heat Flow B. Heat Absorption C. Pressure and Boiling Points D. Relative Humidity V. Refrigerants A. Types of Refrigerant B. R-134a C. HFO-1234yf D. Alternate Refrigerants E. CO2 Systems F. Basic Operation of an Air-Conditioning System VI. The Air-Conditioning System and Its Components Hint: Display a variety of air-conditioning components. They can be mounted to a parts ID board and the students can practise identifying them and describing their functions in the system. A. The Compressor 1. Piston Compressor 2. Variable Displacement Compressor 3. Rotary Vane Compressor 4. Scroll-Type Compressor B. Compressor Clutches C. Electric Drive Compressors D. Refrigerant Oils E. Condenser F. Subcoolers G. Receiver/Dryer H. Accumulator I. Thermostatic Expansion Valve/Orifice Tube J. Evaporator K. Refrigerant Lines L. Sight Glass M. Blower Motor/Fan VII. Air-Conditioning Systems and Controls A. Evaporator Pressure Control System B. Cycling Clutch System 1. Cycling Clutch System with Thermostatic Expansion Valve 2. Cycling Clutch System with Orifice Tube (CCOT) C. Compressor Controls 1. Ambient Temperature Switch 2. Thermostatic Switch 3. Pressure Cycling Switch 4. Low-Pressure Cutoff, or Discharge Pressure Switch 5. High-Pressure Cut-out Switch 6. High-Pressure Relief Valve 7. Compressor Control Valve 8. Electronic Cycling Clutch Switch (ECCS) D. Solar (Sunload) Sensor VIII. Temperature Control Systems A. Manual/Semiautomatic Temperature Controls B. Automatic Temperature Control

9-2

Automotive Technology: A Systems Approach, 3Ce C. Case and Duct Systems D. Dual-Zone and Multiple-Zone Systems E. Rear Systems

ADDITIONAL TEACHING HINTS • • •

Review the functions of the primary components of a heating system. Review the functions of the primary components of an air-conditioning system. Discuss the special handling procedures for automotive refrigerants.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

There will be numerous stumbling blocks associated with air conditioning due to the fact that we are dealing more with chemistry than mechanical components to make the system function properly. The refrigerants in the systems have unique properties to make them suitable for removing the heat from the passenger compartments. Use the section titled “Theory of Automotive Air Conditioning” on page 1671 of Chapter 54 to help with the explanation. Another stumbling block will be to determine the state of the refrigerant in each area of the air conditioning system components. Use the section titled “The Air-Conditioning System and Its Components” on page 1675 to aid in this explanation. Also have the students use the sense of touch to realize the state of the refrigerant in each component.

SHOP ACTIVITIES AND CASE STUDIES Here are some activities you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using a hybrid vehicle and service information, locate and record the cooling system components found only on (and unique to) hybrid vehicles. 2. Using a vehicle equipped with air conditioning, list all the components on the vehicle and their locations. Using service information, report which components are located on the high side of the system and which components are located on the low side.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. The amount of heat necessary to change the state of a substance is called its latent heat. 2. Late-model vehicles use a stationary coil clutch. 3. Because R-134a refrigerant is HFC-based instead of CFC-based, it is said to cause less damage to the earth’s ozone layer. Production phase-out of all CFCs began December 1, 1995, and R-134a became the refrigerant of choice for late-model vehicles. 4. Cycling clutch systems use a thermostatic switch placed in series with the compressor clutch circuit. The thermostatic switch has two purposes: (1) it deenergizes the clutch and stops the compressor if the evaporator is at the freezing point

9-3

Automotive Technology: A Systems Approach, 3Ce and (2) on some systems, it controls temperature by cycling the compressor on and off intermittently. 5. Objects can be in one of three forms: solid, liquid, or gas. Change of state means that the object changes from one state to another with the consumption or release of large amounts of energy. Large amounts of temperature may be transferred by an airconditioning system in this manner. 6. b. Refrigerant leaves the condenser as a warm-temperature, high-pressure liquid. The condenser allows the high temperature refrigerant vapour to cool sufficiently to condense to a liquid. 7. c. Humidity from the passenger compartment air condenses on the evaporator surface while the air-conditioner is running. When the air-conditioner is shut off, this moisture drips from the evaporator case similar to a defrosting refrigerator. 8. a. The accumulator in the fixed orifice tube air conditioning system contains the desiccant that traps or removes moisture from the refrigerant. 9. c. The state of the refrigerant when it leaves the evaporator is a low-pressure vapour. The heat from the passenger compartment air circulating through the evaporator allows the liquid refrigerant to boil to a vapour. 10. d. Refrigerant leaves the compressor as a high-pressure, high-temperature vapour. The compressing of the vapour raises the temperature. 11. a. The condenser is usually located just in front of the radiator. This location allows cool air to flow through the condenser fins to remove excess heat for proper condenser operation. 12. a. Vehicle manufacturers are searching for a replacement for R-134a due to the fact that it contributes to the greenhouse effect. 13. c. The latent heat required to evaporate the liquid refrigerant is the reason for the extreme heat transfer at the evaporator surface. 14. b. The compressor and the thermostatic expansion valve separate the air-conditioning system’s high and low sides. Low pressure vapour is present at the compressor inlet and the compressor changes it to a high pressure. The high pressure liquid refrigerant at the inlet of the thermostatic expansion valve is restricted or metered to a low pressure at the outlet. 15. d. A burnt-out resistor in the heater blower motor circuit could cause no air flow when the fan selector is in the low speed position only. 16. a. The stationary coil type of compressor clutch is used on most modern vehicles. 17. c. R-134a refrigerant must also be recovered because it contributes to the greenhouse effect. 18. d. Although ester oils were recommended for earlier conversions from R-12 to R134a refrigerants, it is now common practice to use PAG oils in R-134a systems because of their superior lubrication qualities. 19. b. The water control valve can prevent hot coolant from reaching the heater housing. 20. a. The accumulator ensures that only vapour reaches the compressor.

9-4

Automotive Technology: A Systems Approach, 3Ce

CHAPTER 55 Heating and Air-Conditioning Diagnosis and Service CHAPTER OVERVIEW This chapter explains the handling procedures for automotive refrigerants, retrofitting A/C systems, and A/C troubleshooting and service procedures.

LEARNING OUTCOMES

• •

Understand the special handling procedures for automotive refrigerants.

Explain the concerns and precautions regarding retrofitting an air-conditioning (A/C) system.

• • •

Describe how to connect a manifold gauge set to a system. Describe methods used to check refrigerant leaks.

Use approved methods and equipment to discharge, reclaim/recycle, evacuate, and recharge an automotive air-conditioning system.

• • •

Perform a performance test on an A/C system. Interpret pressure readings as an aid to diagnose A/C problems. Diagnose and repair A/C control systems.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS I. Maintenance Precautions II. Refrigerant Safety Precautions A. Special Precautions for Hybrid Vehicles III. Guidelines for Converting (Retrofitting) R-12 Systems to R-134a A. Refrigerants IV. Initial System Checks A. Inspection 1. Simple Checks 2. Sight Glass V. Diagnosis A. Noise 1. Clutch Noises 2. Hose Noise 3. Compressor Noise 4. Hissing or Whistling B. Odours

9-5

Automotive Technology: A Systems Approach, 3Ce 1. Cabin Filters VI. Air-Conditioner Testing and Servicing Equipment A. Manifold Gauge Set B. Purity Test C. Service Valves 1. Stem Service Valve 2. Schrader Service Valve D. Quick-Connect Fittings E. Leak-Testing a System 1. Visual Inspection 2. Stop Leak Products 3. Electronic Leak Detector 4. Fluorescent Dye Leak Detection 5. Leak Detector 6. Adding Fluorescent Dye VII. Service Procedures A. Certification B. Refrigerant Recovery C. Recycling D. Compressor Oil Level Checks E. Performance Testing VIII. General Service A. Clutch Service 1. Clutch Clearance 2. Clutch and Pulley Replacement 3. Clutch Pulley Bearing Replacement B. Compressor Service 1. Shaft Seal Replacement 2. Flushing 3. In-Line Filters C. Compressor Controls D. Hoses and Fittings 1. Rigid Line Repair E. Receiver-Dryer/Accumulator 1. Accumulator F. Evaporator 1. Evaporator Water Drain G. Odour Control 1. Expansion Devices H. Condenser IX. Recharging the System A. Charging B. Charging Cylinder 1. Testing for Noncondensable Gases X. Climate Control Systems A. Self-Diagnosis B. Blower Motor C. Doors and Ductwork D. Controls 1. Control Panel E. Solar Sensor ©2016 Nelson Education Ltd.

9-6

Automotive Technology: A Systems Approach, 3Ce XI. Heating System Service A. Basic Heater Inspection and Checks

ADDITIONAL TEACHING HINTS

•

Demonstrate how to hook up air-conditioning system gauges and check the line pressures for R-12 and R-134a systems.

• • •

Explain the concerns and precautions regarding retrofitting an A/C system. Demonstrate how to connect a manifold gauge set to a system. Demonstrate methods used to check refrigerant leaks.

WHAT ARE COMMON STUDENT MISCONCEPTIONS AND STUMBLING BLOCKS? •

•

Due to the fact that experience will help immensely when diagnosing and repairing an airconditioning system, have the students connect the manifold set to as many vehicles as possible and especially vehicles with A/C faults to see pressures that are a fault. Use the section titled “AirConditioner Testing and Servicing Equipment” on page 1706 of Chapter 55 as one reference to this section. Students will at times not put as much emphasis on the environment concerns associated with A/C refrigerants as they should. Spend time discussing the long term ramifications associated with this concern. Have the students spend time searching for leaks in the systems using the correct equipment and also use the section titled “Leak-Testing a System” on page 1708 as a reference.

SHOP ACTIVITIES AND CASE STUDIES Here is an activity you can review in-class as a group, or ask students to complete individually or in pairs: 1. Using an electronic leak detector and fluorescent tracer system, check an air-conditioning system for leaks. CASE STUDIES 2. A technician is diagnosing an air-conditioning system. With the manifold gauge set connected and the system stabilized, the gauges indicate readings lower than specifications on the low side. The technician also notices heavy frost on the inlet of the expansion valve. What can be the cause of this problem? 3. While doing a performance test on the air-conditioning system of a 2012 Honda Civic, the gauge readings are within specifications. The customer’s complaint is that the discharge of air is warm. What other components can cause this problem?

ANSWERS TO TEXTBOOK REVIEW QUESTIONS 1. When you suspect that an alternate refrigerant has been installed in the system, conduct a purity test and use a refrigerant identifier. Equipment is available to do both of these checks. Knowing what refrigerant is in the system and what condition it is in will help you determine what steps are needed to properly service the system.

9-7

Automotive Technology: A Systems Approach, 3Ce 2. Vacuum is any pressure less than atmospheric pressure. Total vacuum may be defined as the total absence of air. 3. A manifold gauge set can be used for recovering, evacuating, charging and diagnosing trouble in air-conditioning systems. Because R-12 and R-134a are not interchangeable, different gauge sets are required for the different systems. 4. Use a digital multimeter (DMM) to test the compressor clutch coil. 5. Refrigerants should not be vented to the atmosphere because most refrigerants will destroy the ozone layer or add to the greenhouse gases. 6. c. Evacuation pulls all traces of air, moisture, and refrigerant from the system. 7. d. The accumulator must be cool to the touch. The heat absorbed by the refrigerant in the evaporator continues to boil the refrigerant as it continues to travel to the compressor. The boiling refrigerant in the accumulator draws the heat from the accumulator’s surface. 8. d. The new shaft seal should be coated with refrigerant oil and placed into the jaws of the seal remover/installer tool. Install a seal protector over the threads of the compressor’s shaft. With a gentle twisting motion, slide the seal over the protector and into the groove in the compressor. 9. b. Refrigerant is added to the low side when the compressor is running. 10. b. When using a manifold gauge set to evacuate an R-134a air-conditioning system, the centre yellow service hose should be connected to the vacuum pump. 11. a. A water flow valve stuck in the closed position could cause a heater to not provide heated air. 12. b. Polyalkalene glycol (PAG) oil should be used in an R-134a air-conditioning system. 13. d. An abrupt temperature change at the centre of the condenser would indicate that the condenser is restricted at the temperature change point. 14. c. The presence of oil around an air-conditioning line fitting is an indication that the fitting is leaking refrigerant. Oil is carried with the refrigerant as it travels through the leaking fitting. 15. c. Because the accumulator contains the moisture absorbing desiccant, the accumulator should be changed when an air-conditioning line is damaged to the point that all refrigerant is lost. 16. a. The two temperature change points in the fixed orifice tube air-conditioning system should be at the compressor and at the orifice tube. 17. b. A thick frost build-up on the suction line to the compressor would indicate that the thermostatic expansion valve is flooding the evaporator. 18. d. An electronic leak detector is considered the best method of finding refrigerant leaks. 19. b. When a vacuum of 740 mm Hg (29 in. Hg) is reached during evacuation; the vacuum pump should remain on for a minimum of 30 minutes. 20. d. R-134a comes in light blue containers.

9-8