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Feature Stories 06 The Black Art of Differentials Pt. 2 by Greg McGoniga
Lots of useful, interesting subtleties this time...
28 Locked Up by Kerry Jonsson
Anti-Lock brake systems have been around for 30 years. With more and more vehicles offering dynamic stability control, we find the wheel speed sensors are still at the heart of the matter.
38 Electric Slide by John Anello
An Escape Hybrid no-start sends our man John on a research binge
50 New Motor Oil Standards by Tom Nash
They will change the way your shop purchases oil and markets maintenance programs to your customers.
66 Prius Inverter Cooling by Paul Cortes
The Prius uses an independent cooling system to cool the inverter and Motor/Generator. In warm weather, problems with the inverter cooling system are fairly common
Cover Story 18 Another Mystry Solved: Durango in Disguise by John Anello
A Dodge Durango involved in a front end collision lights up the ABS warning light. February Februa Feb rua ua ary y 201 2 2010 0 | Ma MasterTechnician asterTechnician Online
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Christopher M. Ayers, Jr. President/Publisher
cayers@mastertechmag.com Bob Freudenberger Editor
bfreud@mastertechmag.com John Anello • Steve Campbell Paul Cortes • Kerry Jonsson Phil Fournier • Chip Keen Greg McGoniga • Tony Molla Tom Nash • Henry Olsen Matt Ragsdale • Dave Russ Contributing Editors
bfreud@mastertechmag.com Christopher-Michael Ayers Art Director, Project Mgr.
ayersc3@mastertechmag.com Joann Turner Circulation Manager
jturner@mastertechmag.com
Editorial, Circulation, Advertising Sales and Business Office: Master Technician Magazine 486 Pinecrest Rd. | Springfield, PA | 19064 P.484.472.8441 • F.484.472.7460 If you have a letter to the editor, a Tech Tip or story idea, click here: bfreud@mastertechmag.com, or on this website at www.mastertechmag.com. Master Technician is published by Master Technician, LLC. The publisher and editors of this magazine accept no responsibility for statements made herein by advertisers or for the opinions expressed by authors of bylined articles or contributed text. The online version of Master Technician magazine is free to qualified automotive repair shop owners, managers & technicians. Contact ayersc3@mastertechmag.com for more information. All other content on is available on a subscription basis. Visit www.mastertechmag.com for subscription information.
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2
by Greg McGoniga
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Posted to mastertechmag.com January 18, 2010 Key Word: Differentials
Honed-out bearings.
hat do you have to do when the ring and pinion are junk? Well, a lot more work! You’ll need new gears, bearings, crush sleeve, gaskets and seals, a way to measure pinion depth and a shim assortment for both depth and backlash/bearing pre-load. To ease pinion depth checking, I have several bearings that I’ve honed out to make them slip bearings. If you want to lighten the load, you can check your honed bearings against the final press-on bearing with a micrometer to verify that the inner race height is the same. In my experience, they are nearly always within a half-thousandth (.0005 in.). If in doubt of the country of origin, measure to be sure. Some of the off-shore companies don’t hold
W
Ford pinion depth shims. February 2010 | MasterTechnician Online
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2 dimensional tolerance worth a damn. If there’s a significant difference, just add or subtract shim thickness to compensate for the difference between your slip-fit test bearings and the final pressed version. Pinion depth is the distance between the centerline of the ring gear and the nose of the pinion; the flat face of the pinion for most applications, but on a Ford nine-inch it’s measured from the small nose that fits into the rear pinion pilot or support bearing. Moving the pinion into or out of mesh changes the contact points between the gears, which moves the mesh pattern up and out of the ring gear, or down into root of the gear. Incorrect mesh is noisy and will wear the gear out in short order.
To set pinion depth, install the pinion races and fit the pinion with a depth shim under your slip bearing. I start with the factory shim. You can install the front pinion bearing and flange, or you can do what I do and use a large washer or piece of U-channel across the nose of the housing with an un-staked nut to hold the pinion tightly against its race. The quickest way to find the right shim for the pinion is by measuring the old and new pinion head thicknesses and comparing them. Look, if both are the same thickness, then the same factory shim will be correct. If the new pinion head is five thousandths thinner, you’ll need a shim five thousandths thicker to move the new pinion head into the same position as the old head. Then, set up your pinion depth checking tool and verify that the checking height is correct. Install the pinion with the press bearings, set the preload, and recheck depth and you’re done with the pinion. Installing a new ring on the carrier requires a few extra steps. Using a large file, draw-file the back of the ring to remove any burrs or
U-channel to hold pinion. 8
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2
Filing the ring.
imperfections. Lightly file the carrier mounting flange, and then solvent wash both, and air dry. I’ve made a set of studs for the ring gear that I use to align the bolt holes as I set the ring down over the carrier. Using Loctite prep, I clean the holes and bolts and install and torque the bolts in a crisscross pattern with red Loctite on the threads -- yes, even if the bolts use a lock washer. Don’t ask me why I know this is important. It involves some very expensive parts that got converted to scrap. Press the carrier bearings onto the carrier, install the carrier into the housing with the factory shims, check how far off you are on backlash, and move shims out of one side and into the other until backlash comes into specification. You should move
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about 1.5 times the backlash needed in shims. For example, if you’re trying to add an additional .004 in. backlash, move a .006 in. shim from the non-pinion side of the carrier to the pinion side. You have to move the ring gear away from the pinion centerline to increase lash and toward the pinion centerline to decrease lash. The actual amount of shim you have to move varies with ring gear size and ratio, but one and a half times will get you in the ballpark. Oh, and don’t just take out .006 in. You have to move it from one side to the other to maintain carrier bearing preload. Finally, check your work with marking compound. Paint four or five teeth on both the drive and coast side, hold the pinion flange with channel locks, and, using a
wrench on the head of the ring gear mounting bolts, turn the ring against the pinion in both the drive and coast directions. Compare your results with the pictures supplied by the gear manufacturer and if everything looks good, button it up and take it for a test drive.
A bad coast pattern.
Hints, Factoids and Other Stuff Case spreaders make life much easier when installing side bearing shims. If you have to pound the side shims and carrier races in, use brass or lead. Brass and lead will pass through the gears without damaging them. Drive pinions and ring gears come in right-hand and left-hand configurations, and a gear set comprises one right-hand gear and one left-hand gear. Place the gears on a table and you’ll see that the gear teeth cant up and down. Look for the gear tip that’s lowest -- which of your hands is it on? The low gear tooth closest to your left hand or right hand determines
Now, a good coast pattern . . .
. . . and a good drive pattern. February 2010 | MasterTechnician Online
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2
A case spreader sure makes things easier.
the gear’s “handedness.” See the accompanying photos to clarify. You can rough in carrier bearing preload by subtracting the pinion bearing pre-load from the total assembly turning torque. I’d expect to see something in the 30-40 inchpound range for the complete assembly with new bearings, without axles. This is a left-hand pinion.
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Measure and record things as you take them apart. Measure the old pinion bearing inner race, the old carrier bearing inner race, the carrier and pinion shims, and distance from the cap mounting surface to the pinion head. If old bearing dimensions and new are the same, it’ll go together just like it was and you can confirm it with the pinion measurement. New gear sets are pre-lapped, but nearly all come with lubrication and break-in recommendations. Follow them. Pinion depth shims can either go under the rear pinion race, or on the pinion shaft under the rear pinion bearing. The Ford nine-inch uses a variable thickness shim under the pinion carrier assembly.
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February 2010 | MasterTechnician Online
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2 Bearing pre-load can be set by crush sleeve or by shim. You can also use a crush sleeve elimination kit to convert a crush-sleeve application to a shim application for highperformance work. Backlash and carrier bearing preload can be set by shim or by adjusting nuts. Shims can be placed under the bearings or under the races. Some Fords use an adjusting nut with holes drilled in it to accept a spanner, and some Chryslers use a nut with a hex in the middle of it. There’s a special tool to reach down the axle tube to engage the hex on a Chrysler. Oil the adjusting nut threads and make your last adjustment on the pinion side nut to set backlash and pre-load at the same time. I try to get about two-thirds of the backlash before the final adjustment, and gather up the last third I need while I preload the bearings by tightening the pinion side nut. When crushing a crush sleeve, move slowly and with intent. It’ll go from no pre-load to locked-up in no time flat. You can use an impact, but it’ll take finesse. Short bursts are the safest way to go with an impact. 14
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Remember, you can damage a bearing with an impact. I’ve got a big flangeholding tool and a four-foot breakover bar in ¾ in. I like to use. If you over crush it, you’ll need a new sleeve. Go with 12-18 in. lbs. of pre-load on used bearings, and 25-30 in. lbs. with new bearings. Check backlash at six or seven points around the ring gear. Adjust the tightest point to specification. Make sure everything is clean and dry for assembly. Dirt on the shims can make the pre-load settings read correctly on assembly only to have it go away when the dirt crushes or washes out. Lose the preload, and bearings quickly fail. Don’t pattern-check a gear until the backlash is set. In some cases, the pattern may not look like the pictures since machining vagaries may change the way the gears mesh. A pattern that’s centered between the root and top of the tooth is usually correct, and the heel end of the pattern on both the drive and coast sides should resemble a round-nosed bullet. I’ve found it’s easier for me to judge the coast side of the pattern.
Using Master Housing Depth Dimensions to Determine Pinion Depth Determining pinion depth on pinions that are not marked can be done using the Master Housing Depth Dimension and a pinion depth setting tool. Refer to the drawing to see how to determine your initial settings. I’ve included as many MHD dimensions as I was able to find. Where bolt counts are mentioned, they refer to the number of bolts attaching the ring to the carrier. Ring gears are measured face-up across the teeth, outside edge of tooth to outside edge of tooth. Just do the following… 1. Measure the pinion head thickness (from the top of the head to the bearing mounting surface.) 2. Subtract your measurement from the Master Housing Dimension. 3. The result is the pinion depth. I’ve tried this method several times with very good results. In fact, if you have a marked ring and pinion, try measuring the head thickness and
subtracting it from the MHD and see if the result is the same as the markings on the pinion for depth. So far, every one I’ve measured has been the same. Remember, your final quality check has to be done with gear marking compound. General Motors
10 Bolt Differentials • 7.2 inch 3.693 MHD • 7.5 inch 3.787 MHD • 8.2 inch by 25 spline pinion 4.175 MHD • 8.2 inch by 27 spline pinion 4.175 MHD • 8.2 inch by thin 55-64 Corvette 4.125 MHD • 8.5 inch by 30 spline pinion 4.262 MHD • 8.5 inch by 27 spline pinion 4.262 MHD • 1955-1965 10 bolt 4.125 MHD • 1957-1964 Olds and Pontiac 4.620 MHD
12 Bolt Differentials • Corvette and 4WD Chevy trucks
February 2010 | MasterTechnician Online
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T he B l ac k Ar t of Differ e nt ia ls, P a rt 2
• 3.9 ratio and higher 4.575 MHD • 3.7 ration and lower 4.565 MHD • 8.875 inch by 1.438 pinion diameter 4.556 MHD • 8.875 inch by 1.625 pinion diameter 4.670 MHD • 9.3 inch 4.620 MHD
• 8-bolt Pinto 3.450 MHD • 8.8 inch 4.415 MHD • 9.0 inch 4.375 MHD
AMC
8 bolt 8.875 inch 4.500 MHD Dana
Chrysler
• 10 bolt 8.250 inch 4.124 MHD • 10 bolt 8.750 inch by 1.750 pinion stem 4.350 MHD • 12 bolt 8.750 inch by 1.875 pinion stem 4.344 MHD • 12 bolt 9.250 inch 4.625 MHD
Ford
• 6.625 inch 3.500 MHD • 7.5 inch 4.040 MHD • 8.0 inch 4.000 MHD
• • •
•
16
• • • • • • •
• • • •
Dana 30 3.625 MHD Dana 36 3.391 MHD Dana 44 4.312 MHD Dana 50 4.616 MHD Dana 60 5.000 MHD Dana 70 5.375 MHD Pinion Depth for Dana Rear Axles (PINION DEPTH, not Master Housing Dimension) Dana 27 2.094 Dana 40 2.625 Dana 53 2.500 Dana 70 3.500
Here are a couple of websites with good information or additional pictures for you. Richmond Gear Installation Instructions in pdf format: http://www.richmondgear.com/ringandpinion.pdf Wikipedia Gear Nomenclature. All the things you never wanted to know about gears: http://en.wikipedia.org/wiki/List_of_gear_nomenclature There’s a picture of nine-inch Ford being checked with a depth micrometer found at this website, along with a good explanation of how to set up a differential without a dedicated depth tool: http://www.streetrodstuff.com/Articles/Drivetrain/Rear_End/Page_2.php T and D Machine has a good pinion depth checker if you don’t already have one: http://www.tdmach.com/
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February 2010 | MasterTechnician Online
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D uran go i n Disguise
urango in isguise
D
by John Anello
was called in to a body shop for a complaint on a Dodge Durango that was in a front end collision (Figure #1). The truck suffered only minor damage, but the ABS warning light was on. The body shop inspected all the wheel speed sensors for visual damage and made sure the ABS module was properly latched. They also checked all the fuse panels for blown fuses. The shop did not have a scan tool to retrieve any onboard service codes, so I was called in.
I
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Figure 1: Dodge Durango involved in front end collision affected the ABS warning light.
Posted to mastertechmag.com February 25, 2010 Key Word: Durango Disguise
Figure 2: Code C2202 - Original VIN Mismatch/Missing
It’s not uncommon to see a body shop that doesn’t own a scan tool, or is even unwilling to hire a diagnostic tech to resolve onboard computer issues. Most of these shops will use a test light and some old-school tactics to get by. This is not their fault because even if the employees invested in diagnostic equipment or diagnostic training there would be no compensation for their efforts because diagnostic time is usually not allowed in collision estimates. Their job function is strictly to put damaged vehicles back together the way they were built at the factory. This task alone is a huge project involving much precision work and patience. When the car is completed, all the onboard controllers will do an integrity check of the whole vehicle. If there are any problems, they are pretty much guaranteed to illuminate a service light. When I arrived at the shop, I started the vehicle and noticed that
the ABS light was the only lamp illuminated. I next connected my Chrysler Star Mobile to scan the ABS module, and pulled a code C2202 (Figure #2-Original VIN Mismatch/ Missing). This code by its description alone indicated to me that the internal ID of the ABS module did not match the internal ID of the PCM. A lot of manufactures will store all the vehicle configuration and VIN in the PCM, and other modules on board may be required to match that data. This is why you cannot simply place a new or used module on board without holding a welcoming party to make sure this replacement module is properly set up. There is usually a mass of confusion among my garages about reprogramming a module, so I need to clear the air here. Setting up a module may require up to three different procedures. The first may be as simple as installing a VIN as part of a Configuring/Coding procedure. When entering a VIN, you
February 2010 | MasterTechnician Online
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D uran go i n Disguise need to be very careful. Make sure you’re wearing your best bifocals to enter the correct letters and numbers because some manufactures may only allow a new or rebuilt module to VIN once. After that the module is locked, and you own it. The next part of the Configuration/Coding procedure is to enter the proper options for the vehicle. This may be done through a series of Yes/No selections, entering Tire/Axle Ratio, entering a vehicle specific 4-7 digit coding number, or by going through a lengthy process of string-coding as many as 50 two-tofour digit numbers.
The second procedure is the actual reprogramming phase that involves the loading of operating software into the module. This software is usually available from a manufacture website as a download, or from a manufacture CD subscription. To install the software, a user needs a generic J2534-compliant device or a factory scan tool to be used as a pass-through. This software is usually VIN-specific and is updated as needed by the manufactures to resolve vehicle glitches. The third procedure I call “adaptation.” This “relearns” the
Figure 3: the “All DTC’s” menu and discovered that the ABS controller was not the only one pointing a finger. 20 MasterTechnician Online | www.mastertechmag.com
February 2010 | MasterTechnician Online
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D uran go i n Disguise computer so that it may properly control the vehicle. This may include relearning throttle angle, crankshaft position, fuel trim, steering angle, occupant seat weight, power window position, or theft key ID. Now that you have a basic explanation of the process, we can move on to the next diagnostic check I wanted to view the entire network to see what the other controllers on board were seeing and to get more clues so I could dot the “I’s” and cross the “T’s.” I selected the “All DTC’s” menu (Figure 3) and discovered that the ABS controller was not the only one pointing a finger. The CCN, FCM and ORC also complained of a VIN mismatch as well as a configuration error. This now ruled out the ABS module as a possible suspect because too many other network fingers were pointing in the direction of the
Figure 4: Invalid VIN
22 MasterTechnician Online | www.mastertechmag.com
PCM. The body shop told me that they never replaced any controller on board. They also called the owner of the vehicle who stated that, “There never were any lights on before the accident.” But you know how that goes. So, my next move was to go to the PCM “Miscellaneous Functions” menu to check the PCM VIN. When I did this, I was surprised to see the “This VIN is Invalid” (Figure #4). This was not a case of a wrong VIN, but of one that was corrupted. The first two characters of the VIN were actually vertical space bars. There was no way someone could have typed these in to the PCM because the factory tool does not supply these characters as a selection and the scan tool would never validate such an entry. The only possibility that I could come up with is that maybe when the battery went completely dead, the
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February 2010 | MasterTechnician Online
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D uran go i n Disguise VIN defaulted to a corrupt insertion of VIN characters. There is also a good possibility that the nonvolatile memory of the PCM could not
hold its information properly after a loss of keep-alive power. I selected “Next� and entered the correct VIN characters (Figure #5). I proceeded
Figure 5: Correct VIN number entered.
Figure 6: Star Mobile validated the entered VIN.
Figure 7: Main ECU View menu and there were no codes stored in any controllers. 24 MasterTechnician Online | www.mastertechmag.com
to the following step and the Star Mobile validated the VIN as a good entry (Figure #6). I now went back into the “View All DTC’s” menu and cleared the entire network of error codes. I started the vehicle three times in a row with 10 seconds on and 10 seconds off to allow all controllers on board to perform a three-trip
Figure 8: Dodge Durango with complaint of Tire Pressure Monitor light on.
integrity check, and the ABS light was now extinguished. As a final check I went into the main ECU View menu (Figure #7) and there were no codes stored in any controllers. This vehicle was a perfect example of how a shop can be married to a vehicle even if a job was performed using flawless craftsmanship. When the battery is disconnected for a long period of time, most vehicles will need to go through a series of relearn procedures. Some of these procedures may even require a factory scan tool. Configuration and coding
Figure 9: Six codes stored in the Cabin Compartment Node pertaining to heated seats that the vehicle did not have. February 2010 | MasterTechnician Online
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D uran go i n Disguise
Figure 10: A vehicle restoration using the Vehicle Preparation menu found in the scan tool.
information is usually held in the nonvolatile memory of a controller and should not be lost in battery power loss situations. I have seen many cases of controllers defaulting to factory options, but have never come across one with a corrupted VIN. While I was writing this story, I came across a 2004 Dodge Durango with a complaint of a Tire Pressure Monitor light on (Figure #8) after a battery was disconnected. This vehicle was not equipped with a TPM
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system. There were also six codes stored in the Cabin Compartment Node pertaining to heated seats that the vehicle also did not have (Figure #9). The only fix was to connect the Star Mobile to Chrysler’s server and perform a vehicle restoration using the Vehicle Preparation menu found in the scan tool (Figure #10). I hope this story will shed some light to help you through a similar adventure.
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February 2010 | MasterTechnician Online
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Loc cked ked Up
Locked Up Anti-Lock brake systems have been around for 30 years. They offer increased safety during panic-stop situations. With more and more vehicles offering dynamic stability control, we find the wheel speed sensors are still at the heart of the matter. by Kerry Jonsson
he concept is fairly simple. A sensor mounted on the hub monitors the speed of the wheel. Under braking conditions, a control unit monitors the speed of each wheel. When the sensor sees that one wheel has stopped moving, but the others still indicate movement, the control unit knows traction has been lost, so it operates a solenoid in the brake hydraulic system that reduces brake pressure to the stopped wheel. This allows that wheel to regain traction.
T
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Since the vehicle is under braking, pressure is reapplied to the wheel that is now rotating. If the wheel indicates lock-up the whole process starts over again. With the addition of traction control, the wheel speed sensors perform another job. They now must monitor wheel speed under acceleration. If the traction control unit sees that a drive wheel is accelerating faster than the others, a host of responses can occur. Brake pressure can be applied to the
Posted to mastertechmag.com February 11, 2010 Key Word: Locked Up
Above: If you are going to use a scan tool to diagnose a problem, choose the graphing feature. You can see the problem here on this ’02 Corvette. Notice how the left front wheel sensor readings spike under acceleration. If this happens on a drive wheel, the PCM may try to reduce power or apply brake pressure to stop wheel spin. Left: On most RWAL systems, the speed sensor is mounted on the differential. It can also be mounted in the transfer case output shaft on four-wheel-drive vehicles. Since there is no other signal to compare it to, you should know a proper resistance reading and AC voltage specification for a given speed. February 2010 | MasterTechnician Online
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L o cked U p runaway wheel until it is traveling the same speed as the others. This loss of traction can be broadcast through a CAN (Controller Area Network) to other control units. Many different control units can respond in a way that will help traction be restored. Ignition timing advance may be cut to reduce the power output of the engine. On vehicles with an electronic stability program, the suspension will chime in and adjust its damping rates. If the vehicle has an electronic throttle, the intake opening may be “relaxed” to reduce horsepower output. All of these responses can be skewed as a result of incorrect wheel speed sensor readings that are originally found in the basic ABS. Since they have such a profound effect on how the vehicle drives, they can create many problems when something is not working right. Very often, you will not see any DTCs (Diagnostic Trouble Codes) for these symptoms because the ABS is just doing what it was designed to do. If the wheel speed sensors were to lie to the control unit, the system will not react as it was designed to. From the control units point of view, everything is normal, so why should it flag a code? 30 MasterTechnician Online | www.mastertechmag.com
In these cases, it’s up to the technician to determine which sensor is not functioning properly. You need to look at the symptoms, start testing components, and determine which component must be replaced. Not an easy task these days.
Testing, Testing, Testing How are we going to test wheel speed sensors? How will we determine which one is bad and which ones are working properly? Are you going to need any special equipment? Although many of us look for any excuse to buy a new tool, most of the situations you come across do not require any more than your DMM (Digital Multi-Meter). Most wheel speed sensors are pulse generators, typically a two-wire sensor with a winding in its element that picks up the number of teeth on a tone wheel. The high and low spots in the tone wheel create a changing magnetic field that induces an AC voltage signal. When the pulsing signal stops, that means the wheel
* Details available at your authorized BMW center. Š2008 BMW of North America, LLC. The BMW name, model names and logo are registered trademarks. All rights reserved.
February 2010 | MasterTechnician Online
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L o cked U p has locked up. For the purpose of this article, we’re going to focus on AC pulse generators. There are “active” wheel speed sensors that operate on the Hall effect, but testing those sensors will be covered in future installments of Master Technician. Usually, the first thing we reach for on any computer-controlled One of the first tests you should perform on a pulsegenerator type sensor is that for resistance. On this ’99 Durango with RWAL brakes, you should have a reading of about 1,700 ohms. The factory flow chart tells you 1,600 to 2,300 is okay but we’ve seen problems within this wide range.
32 MasterTechnician Online | www.mastertechmag.com
system is our scan tool. Most of these can access domestic ABS systems. Normally, we use the scan tool for the first steps of our diagnosis, then we back up our findings with direct component tests. You can go into data and monitor the wheel speed sensor values while driving and compare them to one another. Of course, be careful while road testing a vehicle and evaluating data. Try to have someone else drive. On the betterequipped scan tools, you should have the ability to graph the data of the wheel speed sensors. This is a big help when looking for intermittent drops in the signal voltage. You can
usually graph all four, or at least two, of the wheel speed sensors at the same time. You may also be able to record the road test and play it back when you return to the shop. This is safer than watching the data while driving. Look for sharp drops in wheel speed, and compare one sensor to another. Dramatic changes in a wheel speed signal, particularly under braking, can lead to ABS activation when it is not required. We can check the integrity of the sensor’s winding with a simple resistance test. The difficulty comes in knowing a known-good value. Very often in factory flowcharts (remember, we may not have any codes), the resistance specification takes in too wide a range to be useful. If your previous experience cannot help you, try comparing the resistance to the other sensor on the same axle. Often the front sensors have a slightly different resistance to the rear sensors in four-wheel ABS. On a rear-wheel systems, there is usually only one sensor mounted in the transmission tailshaft or rear differential. On vehicles with fourwheel-drive, it may be mounted in the transfer case.
Resistance tests will let you know if the sensor is bad, but just because it passes the test doesn’t mean that it’s good. To determine if a wheel has locked up, the ABS control unit looks at the AC voltage signal. You can also check the AC voltage signal with our DMM. Connect the two leads of you meter to the two wires from the sensor. You will have to spin the wheel by hand to generate voltage. You should compare the signal voltage with the other sensor on the same axle. They should produce about the same voltage. If not, the weaker of the two sensors is most likely the problem. If you’re having a problem determining the AC voltage signal strength, try using your DMM’s MAX/MIN feature. You can replace the sensor at this point, but there are other conditions you need to be concerned with. The sensor may actually be okay. Rust, dirt and road debris may be interfering with the signal. A simple cleaning of the sensor tip and tone wheel may correct the problem. You should also measure the air gap between the tone wheel and the sensor. Make sure the gaps are the same from side to side.
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L o cked U p If the ABS sensor is mounted in the wheel bearing, as on GM cars and trucks, you will have no choice but to replace the wheel bearing assembly. In addition, a worn out wheel bearing will change the AC voltage signal and cause low-speed ABS activation. We understand that most ABS sensors get destroyed while being removed, but you should still consider cleaning the tone wheel with a wire brush. Also, while the sensor is out you should inspect the tone wheel for cracks and
replace it if any are found. Finally, make sure the tone wheel is secured to the axle shaft or hub assembly. A loose or damaged tone ring can put out a bad wheel speed signal.
Pulling Out the Big Guns
If you do not find any answers with these conventional methods, you are going to need to pull out the big guns. An oscilloscope Connect the leads just as you would for may be the only sure-fire a resistance test, and with your DMM way to determine where in AC Volts spin the wheel by hand. You should generate an AC voltage signal. the problem is. Basically, On 4WAL systems, you should see the an oscilloscope measures same voltage reading from one side of the voltage signal and and axle to the other by spinning the wheel at about the same speed. displays it in a graph. We can now “visualize� the AC signal instead of seeing it in digital form on a DMM. You will want to see equal voltage fluctuations on the peak high and low patterns between the two sensors on an axle. You should also look for equal frequency readings between the two sensors. An ABS control unit can misinterpret variations
34 MasterTechnician Online | www.mastertechmag.com
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L o cked U p in voltage strength or frequency. Of course, you need to be familiar enough with your oscilloscope to make sure the voltage divisions you select are the same for each wheel speed sensor you are testing. Stick with testing the two sensors on one axle. It is not unusual for an ABS to have lower voltage signals from the rear sensors compared to the front sensors. The ABS control unit is designed to interpret the different voltage signals between the front and rear sensors.
Obviously, scopes with a record feature will be a great benefit here. You can review the data without having to drive the vehicle. Otherwise, have someone else drive while you monitor the scope traces and freeze the screen to evaluate the readings. There are two ways to view the signal, but they both amount to the same thing. You can look at the amplitude of the AC voltage signal, which is how high the voltage rises compared to ground. Ground would be the horizontal line that passes through the middle. You
A four-channel scope will let you watch the AC voltage traces. Notice here how the two bottom traces (Red and Yellow) have lower amplitude. These came off of the rear speed sensors. Also notice how the two upper traces (Green and Blue) have different amplitude readings. The Blue trace is clearly the weaker signal.
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can also look at the AC voltage from peak to peak; that is, from the highest point to the lowest point of the trace. Either way you look at it, the signals must be close to one another in peak AC voltage.
signals, the vehicle needs to be driven in a straight line so you can compare amplitude and frequency with both wheels turning at the same rate.
Frequency is just as important, and it is usually measured in Hertz. A Hertz reading means how many times the signal switched from a positive to a negative wave within one second. This is why it is critical to know the number of teeth on each tone wheel is the same. If an axle or hub was changed, it is essential that the number or teeth on the new tone wheel matches that of the old. This will insure the same frequency between the wheel speed signals. When you diagnose one of these problems and you are not familiar with the customer or the vehicle’s repair history, you cannot assume that everything is as it should be. Keep in mind, while interpreting wheel speed signals you should know that they will change in frequency while going through turns as the two front wheels do cover different arcs and thus travel at different speeds. When comparing wheel speed
Since wheel speed is critical to a proper diagnosis, tire size is also critical. Verify that the tire sizes are the same on both sides and correct for the vehicle, and that they are properly inflated. With owners modifying their vehicles these days and CAN systems sharing information, you can end up chasing an owner-made problem. Imagine an ABS control unit trying to make sense out of comparing engine rpm, transmission input/output shaft speed, and wheel speeds and finding out that they are not as they should be due to different tire sizes. Very often, updated programming has to be installed to inform the various control units about the change. A good relationship with your customers and their vehicles will help even the playing field when it comes to diagnosing abnormal ABS, traction control and electronic throttle activation. Maybe now we can relax for five minutes until the next new system comes along. Get ready.
In Closing
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E le ctri c S l ide
by John Anello
An Escape Hybrid nostart sends our man John on a research binge received a call from a body shop for a complaint of a no-start on a 2006 Ford Escape 2.3 Hybrid (Figure #1). The vehicle was involved in an accident and had damage to the front and the transmission housing. The shop had no choice but to replace the entire transaxle assembly to correct a problem with a damaged transmission case. They claimed that the engine ran before they installed the transaxle, but now the vehicle would not start. The shop was well aware of how to disable this hybrid vehicle by pulling the high voltage
I
38 MasterTechnician Online | www.mastertechmag.com
Figure 1: A no-start on a 2006 Ford Escape 2.3 Hybrid.
Posted to mastertechmag.com February 11, 2010 Key Word: Electric Slide
Figure 2: An attempt to start the Escape and it would not do anything. The “Red Triangle of Death” was lit up on the dash indicating a serious hybrid problem.
battery connector. They were also careful to take any precautionary measures to locate any damage to the orange high voltage cabling. Hybrid vehicles are not something to play around with if you are not properly trained on how they work, or if your not aware of the all the precautions you must take while working around them. One false move and you can be seriously injured or even killed. The body shop had no equipment to scan this vehicle, so they called me in for technical assistance. When I arrived at the shop, I attempted to start the Escape and it would not do anything. I noticed that the “Red Triangle of Death” was lit up on the dash indicating a serious hybrid problem (Figure #2).This vehicle also uses a yellow wrench to alert the driver to
Figure 3: A set of insulated boots rated at 15 KVs
a potential problem in the hybrid system, but that wasn’t the case today. The next steps I took were to put on my safety gloves, then my thinking cap, and I made sure I had plenty of coffee in me to keep me alert to my hybrid surroundings. This little Ford was not going to take the Tech Man out on this fine day. The shop did not even own a pair of safety gloves like the ones I carry on board my truck, which are rated at 500V and have to be sent in every three months to be tested for leaks and recertified for use in the field and returned with a new date stamp on them. I even own a set of insulated boots rated at 15 KVs (Figure #3) that were given to me by a friend who works for a public utility company just in case things get really heated up. February 2010 | MasterTechnician Online
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E le ctri c S l ide Replacing an entire transaxle assembly is a huge task, especially on a hybrid, and anything can go wrong during the process. I performed a visual inspection of their installation process, but did not see anything out of order. It seemed that everything was bolted up and plugged in properly. So, I next needed to hook up my Ford IDS factory scan tool so I could read any DTCs that could lead me in the right direction. Keep in mind that hybrids can use multiple computers to operate the hybrid system, so it’s important to check all the ECUs involved. I chose to pull codes from all the controllers at one time so that I could get the whole laundry list on this vehicle. The Powertrain Control Module had code
Figure 4: I walked over to the rear of the vehicle to check the battery disable plug located in the rear compartment 40 MasterTechnician Online | www.mastertechmag.com
P1A10 (Hybrid Powertrain Control Module-Battery Disabled), P1A14 (Hybrid Powertrain Control ModuleTransmission Disabled), and U2510 (CAN communication bus fault), and the TCM had a code P0A0A (High Voltage Inter-lock Circuit). I tried to use a common-sense approach to interpret the code descriptions without having to dig into an information system for help. The battery disable and high voltage interlock circuit faults directed my attention to safety devices used on this Escape. I walked over to the rear of the vehicle to check the battery disable plug located in the rear compartment (Figure #4). A closer view shows that there are three possible positions the plug can be installed in (Figure #5-Lock, Unlock or Service Shipping).The body shop had properly reinstalled the service plug back in its original Lock position. I find quite a few of these plugs in the field that are not latched properly and cause the hybrid vehicle to be temporarily disabled. I even went a step further and removed the plug and used my special CAT5 hybrid-rated Fluke 1587 meter to test the fuse within the safety plug (Figure #6), and that was okay as well.
Ja_`l hYjl& Ja_`l h]ghd]& Ja_`l hja[]& Ja_`l YoYq& O`]f qgm Zmq ?]fmaf] NgdckoY_]f HYjlk qgm _]l egj] l`Yf 9mlgZY`f%l]kl]\$ hj][akagf% ]f_af]]j]\ G=E hYjlk& Qgm Ydkg _]l l`] l][`fa[Yd ]ph]jlak] Yf\ kmhhgjl g^ Y \]\a[Yl]\ l]Ye o`gk] bgZ ak lg _]l qgm l`] hYjlk qgm f]]\ o`]f qgm f]]\ l`]e& ?]fmaf] NO HYjlk Yj] [geh]lalan]dq hja[]\& L`]q eYq fgl YdoYqk Z] l`] d]Ykl ]ph]fkan]$ Zml l`]q _an] qgm l`] Z]kl imYdalq Yf\ l`] Z]kl nYdm]& ?]fmaf] NO HYjlk `]dh qgm \g l`] bgZ ja_`l l`] Òjkl lae]$ Yf\ ]daeafYl] [ge]ZY[ck& O`YlÊk l`Yl ogjl` lg qgmj Zmkaf]kk7 O] `Yn] Y[[]kk lg gn]j )-($((( hYjlk ^gj f]o Yf\ gd\]j eg\]dk Yf\ o] [Yf _]l l`]e lg qgm ^Ykl& L`YlÊdd c]]h qgmj k`gh egnaf_ Yf\ c]]h qgmj [mklge]jk [geaf_ ZY[c&
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E le ctri c S l ide Also located in the rear compartment in the right rear quarter panel is a hybrid inertia switch (Figure #7), and in the right front kick panel there’s a fuel inertia switch. Most manufactures use just a high-voltage service plug, but ford uses an inertia switch to quickly disable the hybrid system during a collision. The rear inertia switch got triggered from the impact. Figure 5: A closer view shows that there are three possible positions the plug can be installed in (Lock, Unlock or Service Shipping)
After I reset the hybrid inertia switch, I cleared all codes and attempted to start the vehicle again. Still nothing, and when I checked for codes again
Figure 6: I removed the plug and used my special CAT5 Hybrid-rated Fluke 1587 meter to test the fuse within the safety plug. 42 MasterTechnician Online | www.mastertechmag.com
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E le ctri c S l ide
Figure 7: Also located in the rear compartment in the right rear quarter panel is a hybrid inertia switch. Figure 8
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(Figures #8, #9, #10) the PCM code U2510 came back along with a new PCM code P1A0F (Hybrid Powertrain Control Module-Vehicle Disabled) and a new TCM code P1260 (Theft Detected-Vehicle Immobilized). I was unfamiliar with these codes, so I had to do some digging into my information systems and the Ford website. Having many resources helps to fine tune your diagnostics and quickly gets to the information you need to diagnose a vehicle. I found that the code P1A0F (Hybrid Powertrain Control ModuleVehicle Disabled) dealt with a failsafe mode of the PCM called LOS (Limited
Above: Figure 9
Below: Figure 10
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E le ctri c S l ide Operating Strategy). These LOS modes are made to manage vehicle operation in case of a failure in the engine, transmission, braking, or hybrid battery/charging system, and may put the vehicle into a limp-home mode, or disable it. The PCM LOS codes instruct you to look for failure codes within the PCM or other controllers that initiated the LOS mode and not to condemn the subsystem or component they describe. I now gave more attention to the U2510 stored in the PCM. The IDS listed this code only as “CAN communication bus fault,” but that was very misleading because the Ford website specifically tagged the code as “Data Mismatch” with controllers on board. It specified to pull codes within the TCM to check for any errors and to check if the PCM or TCM differed in configuration data. If the configuration data in each controller did not match, then the anti-theft system would not allow the vehicle to run. At this point the wheels started turning in my head. I remembered that the body shop had told me that they had replaced the entire transaxle assembly. What they also replaced without knowing it was
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the TCM, which is located inside the transaxle assembly. The TCM latched a code P1260 in memory because it did not belong in this vehicle, thus causing the PCM to go into an anti-theft mode. The PCM was in control of the PATS (Passive AntiTheft System). It didn’t put the theft light on, but it did put the vehicle into a failsafe disable mode. There was no As Built data for the TCM on the Ford website for this particular vehicle, but there was a procedure to line up both the PCM and TCM if either controller was replaced. This was done by going to the PATS function main screen (Figure #11) and selecting Parameter Reset. This procedure lines up both modules like a welcome-home party so that they can be paired together. After this procedure was done, I erased all codes in memory and turned off the ignition. When I attempted to start the vehicle, it started up with no lights and everything was back to normal. What a rollercoaster ride of events for this hybrid! It was a learning experience that makes you think beyond the norm when approaching a diagnostic routine. It is so
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E le ctri c S l ide important to understand that there are a lot of system strategies that you must learn as you go, and without the proper resources there is no way you will be able to unravel the problems you encounter in the field. Cars today are forever changing, and it can become very costly if you decide to be a parts changer. You need to constantly educate yourself to stay in the continuously-evolving training loop. It was not long ago (maybe a year) that I knew nothing about hybrids, but I took the time to
sit through many hybrid classes, and even got some hands-on training so that I could successfully tackle these vehicles, and feel comfortable while doing it. I knew it will be a long uphill battle and a huge learning curve for me, but at least I took the time out to give it a try. I can only tell you that I was very charged and revved up when I did fix this Escape, which vehicle had tried to give me the electric slide by thinking it could outdo me. I hope this was a learning experience for you as well.
Figure 11: PATS function main screen 48 MasterTechnician Online | www.mastertechmag.com
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Mo tor O i l Standar ds
By Tom Nash
Two new standards for motor oil will arrive later this year.
wo new standards in the formulation of motor oil that will be used in 2011 passenger cars and light trucks will arrive later this year. The new standards are required to reduce emissions, improve engine efficiency and lengthen engine life.
They will change the way your shop purchases oil and markets maintenance programs to your customers. You need to be informed and ready to hit the ground running as the new standards may affect your shop’s net profit margin.
Some industry observers, however, point out the downside of the changeover to the new standards: higher prices to cover the costs of research and development; testing and certification; more expensive ingredients; licensing fees and royalties.
T
50 Ma MasterTechnician M aste st rTechn rTe Techn ch ici ician ic a Onl an O On Online n ine ine in e | www ww w www.mastertechmag.com ww.ma m ste ma erte echmag. chm hmag. h ag g.com m
Posted to mastertechmag.com February 11, 2010 Key Word: Oil Standards
These new longer-lasting oils will also bring longer change intervals – resulting in fewer customer visits to your shop, so you’ll need to take advantage of each opportunity to market additional sales. You will need to perform thorough inspections with checklists and use proper marketing techniques with customers during each visit to find any minor problems that could become major issues if not addressed. This will also create additional revenue for the shop and keep your customer’s vehicle on the road. The two new incoming standards are: ILSAC GF-5 and General Motors “dexos.” How and why they differ, what each means and how they will affect you and your customers will be explained, but first we need to define these “standards” and “specifications” and the entities involved. It’ll help you understand all those acronyms and references you see on oil bottles and drums.
Motor Oil Standards and Specifications Motor oil standards and specifications have been developed by various organizations to ensure consistency, compatibility and quality from oil formulators, companies and marketers – those who produce, package and sell motor oil for automotive vehicles.
SAE Viscosity Standards The Society of Automotive Engineers (SAE) was formed in 1905 with the mission to standardize all the technological aspects of automobile design, manufacture and maintenance. Motor oil and lubrication became one of the early projects of the SAE. As early as 1911, petroleum refiners began to embrace
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Mo tor O i l Standar ds SAE standards for viscosity. Refiners still use the SAE J300 (one of the first standards) method of testing and certifying the viscosity of motor oil.
API Ratings During World War I, the United States Congress mandated the domestic oil and natural gas industry to work together with the government to help the war effort. After the war, there was a need for an organization to continue representing the petroleum industry, so the American Petroleum Institute (API) was established in 1919. API sets category ratings, according to specified testing parameters and approves products based on testing results. The latest API motor oil rating for gasoline-powered passenger car and light trucks is “SM,” which you will find on the oil bottle or drum label. A couple of service ratings are still current: SL; for 2004 and older models and SJ; for 2001 and older models. All others, such as SH, SG, SE and prior are considered obsolete.
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Here’s an explanation of the API “Donut:” 1. Performance Level. Gasoline engine oil categories (for cars, vans and light trucks with gasoline engines fall under API’s “S” (Service) categories. Diesel engine oil categories (for heavy-duty trucks and vehicles with diesel engines fall under API’s “C” (Commercial) categories. 2. Viscosity Grade. A measure of the oil’s thickness and ability to flow at certain temperatures. Vehicle requirements may vary. Follow the vehicle manufacturer’s recommended SAE oil viscosity grade. 3. Energy Conserving. The “Energy Conserving” designation applies to oils intended for gasoline-engine cars, vans and light trucks. Use of these oils may result in fuel savings.
The current API standard for light diesel engines is CJ-4. Two other service ratings: CI-4 and CH-4 are still useable for certain applications, but care should be taken to ensure they meet local and state emissions regulations. Most API service ratings s are “backward compatible”, meaning the oil may safely be used in older vehicles which called for earlier standards – but, always check the service information and owners manual, especially in unusual applications.
ACEA You may see the acronym, ACEA on an oil bottle or a specification sheet or requirement. The European Automobile Manufacturers Association (ACEA), was founded in 1991 to represent the interests of the fifteen European automotive manufacturers. ACEA works with the various countries and the European Union for standardization among the nations. All European-made vehicles list ACEA standards for oil in their specifications, along with ILSAC Standards. The vast majority
of motor oils in North American meet or exceed ACEA standards, so it shouldn’t be an issue when servicing a European vehicle. Always refer to the owner’s manual or check the manufacturer’s technical website, if in doubt.
ILSAC Standards The International Lubricants Standardization and Approval Committee (ILSAC) is a consortium of automakers: General Motors, Ford and Chrysler; and the Japan Automobile Manufacturers Association (JAMA). ILSAC’s oil subcommittee works with API and additive suppliers to identify the need for an improved motor oil specification and sets testing standards. The latest standard is GF-4, which came into usage in early 2004. Since then, the need for longer oil life, improved mileage and lower emissions has hightened. Not long after the GF-4 standard was adopted, the industry began to look at raising the bar for the next generation of engines
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Mo tor O i l Standar ds
The ILSAC New Standard: GF-5 While the GF-4 standard was acceptable when it was introduced six years ago, new formulas will be required to meet upcoming government regulations for improved fuel economy and lower emissions. Intended improvements over the GF-4 standard are: • Better fuel economy • Higher levels of motor oil robustness • Improved protection of emission control systems
The next ILSAC Standard, GF-5, is scheduled to be released this year, about the time the 2011 models hit the market. There are many challenges toward attaining the GF-5 standard. More sophisticated additive mixtures will need to be incorporated for improved: • Fuel economy • Emission systems protection • Rust protection with the use
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of E85 (85% ethanol/15% gasoline blend) • Protection for turbochargers • Avoiding engine sludge • Keeping pistons clean • Compatibility with sealing materials
On November 19, 2009, representatives of ILSAC agreed on a final draft of GF-5. That agreement was sent to members who then voted to pass the standard, clearing the way for licensing the standard to formulators. The product range is expected to include 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30. While each oil company must meet the stringent GF-5 standards, they may take slightly different approaches to meeting the specification in types and amounts of additives and modifiers. One thing is certain: there will be a higher content of additives and synthetic compounds. This will increase oil life, protect the metal and sealing materials better, but increase the cost of the end product. The end price of GF-5 may range from 15-20% higher than the current
GF-4 spec, due to the formulation, development, testing, royalties and marketing costs.
General Motors dexos General Motors has decided to take a separate path to setting standards for its global family of engines. GM will introduce its dexos global motor oil specification with 2011 models. Actually, the standard contains two specifications: “dexos 1,” as factoryfill and service-fill for gasoline engines; and “dexos 2” as factory-fill and service-fill for diesel engines. Both, of course, are compatible with previous models. GM currently manufactures over twenty engines in eighteen plants worldwide and assembles vehicles in thirty seven countries – although all that may change drastically under the new government-controlled strategy. The intent of the global dexos specification is to ensure the same quality and specification from all suppliers for all engines in all countries.
According to Eric Johnson, of GM Powertrain, the reasons for developing the dexos specifications are: • To ensure worldwide availability of equal quality oil for factory and service fill. • To further improve fuel economy. • To provide a more robust formulation for added engine protection. • To further extend service intervals. • To support longer intervals for GM’s Oil Life Monitoring System (OLMS).
GM’s Oil Life Monitoring System (OLMS) uses sophisticated algorithms to calculate the point at which oil must be changed. Courtesy of GM.
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Mo tor O i l Standar ds GM has used OLMS for many years and it is now entering a completely global application. These service intervals, based on engine speed, ambient air and engine temperatures, runtime, etc., will certainly lengthen with the new specification. “We’re always trying to calibrate OLMS to maximize drain intervals to reduce the nation’s dependence on crude oil,” Johnson stated. “It’s about putting the customer first and continuing
GM’s commitment to quality, design and innovation.” For gasoline engines, dexos 1 will be offered in these formulations: 0W-20, 5W-20, 0W-30 and 5W-30. For light diesel engines, dexos 2 will be packaged in 5W-30, 0W-40 and 5W-40. Dexos-1 will supersede the current GM6094M specification for most
Below: This graphic illustrates expected oil change intervals under the current ILSAC GF-4 standard. The intervals are expected to rise significantly under GF-5. Courtesy of GM.
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Mo tor O i l Standar ds GM gasoline vehicles. At this time, GM plans to also use dexos 1 to replace the GM4718M spec for Corvette, Cadillac and engines with turbochargers, which stipulated Class III synthetic blends; Mobil 1 or the equivalent.
specification in the future.” This would include:
Higher Prices for dexos
Johnson wouldn’t speculate on the end cost to the consumer, because it would depend on individual formulation. There has been some industry talk that in order to meet the dexos specification, oil formulators would have to use high levels of molybdenum disulfide (moly), a high quality friction modifier. Due to its high cost, the conjecture is that it would dramatically increase production costs.
Under this new GM proprietary specification, two economic factors will increase the end price of GMapproved dexos oils: the higher cost of more exotic base stocks and additives; plus GM’s licensing fee and royalty structure. GM will charge oil formulators an annual licensing fee of $1,000 per viscosity. Additionally, there will be a 36¢ per gallon (9¢ per quart) royalty. Some industry experts predict a 25-30% increase in cost. However, when considering the much longer replacement intervals, dexos may be cheaper for the consumer in the long run. “The revenue from dexos royalties program,” Johnson said, “would be used to sustain and improve the
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• • • •
Current test replacement Future test replacement Test maintenance Consumer awareness
Johnson said he doesn’t believe high portions of moly are required and believes formulators will meet the specification at the lowest cost. “We just give them a specification to meet – not a recipe.” “There are benefits for both the consumer and GM,” Johnson said. “Under the dexos program, fuel
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Mo tor O i l Standar ds economy will improve and drain intervals will increase, thereby reducing consumption of both fuel and motor oil. It also allows us (General Motors) to be more environmentally-responsible and be more efficient as a company; with one global specification, rather than several.” There also has been some concern that if GM is successful in launching a proprietary specification, other companies could follow suit, creating several specifications. However, most large automakers have voiced their intention to continue following ILSAC standards.
GM dexos Versus ILSAC GF-5 It may seem ironic that GM is launching the dexos specification at the same time that ILSAC is releasing the GF-5 standard – especially because GM chairs the ILSAC oil subcommittee. However, consider this: ILSAC’s GF-5 is generally considered as the next step toward total synthetic products and will probably remain in place no more than five years. GM, on the other hand, is leaping forward a decade or more to establish its own mark. Therefore, it’s expected that dexos will meet (and exceed) GF-5, but GF-5 will not meet the dexos specification.
Expect shelves to become very crowded with the various selections of ILSAC GF-4, GF-5 and GM dexos motor oils.
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Because both GF-5 and dexos products will contain more synthetic compounds and additional additives, the cost is expected to increase. Research and development, plus testing costs by oil formulators and additive suppliers will prompt higher prices. Licensing and royalty fees will also be tacked on. While GF-5 is expected to increase by 15-20%; Dexos is expected to bring a 25-30% premium. This brings the two closer to the price of fully-synthetic blends. It bears repeating that with these products, change intervals will be lengthened, so the overall cost may stay close to – or improve – current cost-permile levels.
How You’ll Be Affected You and your shop will be affected in the following ways: • You will see your customers less often for routine oil changes.
• You will incur higher costs for motor oil. • You will need to buy motor oil intelligently. • You will need to be prepared to explain to your customers why oil costs have risen and that the overall price-permile cost may be cheaper. • You will need to merchandise any additional services the vehicle may need during each visit.
Fewer Customer Visits Less frequent oil and filter change procedures will mean you may see your customers less often. It will become increasingly more critical to maintain contact with your customers to take care of minor issues, to prevent them from becoming big problems. Always maintain good customer records so you can continue your
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Mo tor O i l Standar ds
Oil Group Classification You may see a reference to an oil “group” on the container or in printed materials. Group classification is basically a description of the chemical structure of the base stock. API defines the following groups: Group I base stocks are the least refined products, processd to inhibit oxidation and remove wax. These stocks are now extremely rare in modern motor oil.
The Group V oil you most commonly use is PAG. Most others are used as additives in motor oil or ATF blends.
Many oils labeled as synthetic are actually blends of Group III base stocks and conventional petroleum oil. Courtesy of Castrol
Group II base stocks are further refined than Group I products and are the most commonly used products in basic grade motor oils. The additional purification provides better volatility, higher flash point and improved cold crank viscosity.
Group III base stocks are refined to the highest degree and have higher viscosity indexes and better stability. They are commonly blended with additives and/or synthetic stocks. They are labeled as “synthetic” or “semi-synthetic,” depending on the blend. Courtesy of Castrol
Group IV base stocks are laboratory-created (synthetic) fluids. Polyalphaolefin (PAO) is the most common example found in “synthetic” oil. It’s super slick and resists breakdown under heat and pressure. Group V base stocks are oils that do not fall into Groups I to IV. These products are exotic synthetic additives such as polyalkylene glycol (PAG), perflouropolyalkylether (PFPAE) and other esters.
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Mo tor O i l Standar ds marketing program for preventive maintenance and scheduled services via postal mailers, e-mail, phone messages and even Twitter. Good upto-date records are the critical point. Make the best of each visit. Thoroughly inspect the vehicle for service needed now – and in the near future. Make the customer aware of any findings, market the need for any repair or adjustment, give the customer a copy of the inspection report and make sure to add the findings to the customer’s records.
A Tougher “Sell” The cost of an oil change and filter service will rise. It will be difficult to initially market the increase to your customers unless you are educated about the new oils, why they are better, last longer and are a positive step forward – and can convey that information to the customer. To avoid “sticker shock,” prepare the customer for the cost increase when they arrive. Explain the increase and stress the benefits.
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You can create a small handout to explain the new oil standards why the price has risen. It can also be added to your shop’s website or included in mailers to customers.
Smart Buying It will be important to buy right. It will take a while for GF-5 oils to become widely available. At some point, marketers will cease manufacturing and supplying GF-4 product. You’ll still want to keep a supply of lower-priced GF-4 product on hand for 2010 and earlier models, but you certainly don’t want to hoard it. GM dexos is another matter. You will want to keep a supply on hand but not an overabundance sitting in your inventory. It will be important to track usage and forecast sales. Finally, educate yourself about the new ILSAC GF-5 standard and GM’s Dexos specification. Talk to your suppliers and watch for new service information.
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P r i u s :
P ri u s I n v erter C ooling
by Paul Cortes
he Prius uses an independent cooling system to keep the inverter and motor/generator (M/G) at a safe temperature. In warm weather, problems with the inverter cooling system are fairly common in both the Gen 1 Prius (2001-2003), and Gen 2 Prius (2004-2009). If you’re not already familiar with these systems, this article will bring you up to speed and save you some time
T
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when the first failure rolls through your bay door. Let’s start with an overview of the basics. The inverter cooling system is completely independent of the ICE (Internal Combustion Engine) cooling system. It uses a separate radiator and water pump, and it operates at a lower temperature than the ICE cooling system.
Posted to mastertechmag.com January 18, 2010 Key Word: inverter cooling
Inverter Cooling System
Coolant The inverter cooling system uses the same type of coolant as the ICE cooling system: •Gen 1 was factory filled with Toyota Long Life Coolant (LLC). LLC is full strength and must be mixed with distilled water to obtain the correct ratio (50/50).
•Gen 2 was factory filled with Toyota Super Long Life Coolant (SLLC). SLLC is premixed, eliminating the hassle of mixing and the potential for error. SLLC can be used in Gen 1, but LLC should not be used in Gen 2. The Gen 1 maintenance schedule calls for coolant replacement every 30K miles, but the Gen 2 schedule neglects the coolant for 100K miles. February 2010 | MasterTechnician Online
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P ri u s I n v erter C ooling You may want to consider stocking only SLLC. It will cover 100% of the Toyota line. It’s easier to use since there is no need to premix or stock distilled water. And it’s arguably a superior coolant. The only down side is a slightly higher cost per mixed gallon.
Temperature Regulation
The inverter radiator removes heat from the coolant, and the design and location changes from Gen 1 to Gen 2. The inverter radiators are both positioned to avoid radiant heat from the ICE radiator. With Gen 1, the inverter radiator is located between the ICE radiator assembly and the bumper. It might be mistaken for an oil cooler if it were not for the 16mm coolant hoses attached to it.
Since the inverter and M/G do not need to achieve “operating temperature” to work efficiently, there’s no need for a thermostat or other temperature-based control of the inverter pump. The inverter pump runs any time the power mode is “ON” or “READY.”
On Gen 2, the inverter radiator is the lower section of the ICE radiator, but the ICE and the inverter sections are compartmented -- no coolant is shared between the two. The division is hard to see while with the radiator is mounted in the car, but it’s there.
What’s hot?
Fans & Pump
The heat in the inverter coolant comes from two sources – the inverter and the M/G. Heat sinks in the inverter and the transaxle transfer heat into the coolant.
The inverter radiator is cooled by the same set of electric fans used for the condenser and radiator.
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P ri u s I n v erter C ooling has 4 water pumps total: ICE water pump, heater water pump, thermos water pump, and the inverter water pump. Sorting out what’s what can be time-consuming just by itself if you’re not familiar with the Prius. You’ll find the inverter pump mounted on the body just behind the driver’s side headlight on both the Gen 1 and Gen 2.
Necessary tools •Scan tool: The most important piece of equipment for any Prius
diagnosis or repair is the Techstream scan tool. An older Toyota Intelligent Tester or Vetronix Mastertech with a Genuine Toyota card will also work, but is much slower and does not have the same features. Other scan tools have promised full coverage, but so far none has delivered, at least not reliably. Using one that lacks capability, or provides incorrect information can waste hours of diagnostic time. Any shop can purchase a Techstream here: (https://techinfo.toyota.com/ t3Portal/staticcontent/en/techinfo/html/prelogin/docs/ts/tsprodinfosheet.pdf)
The MG2 heat sink is on the very top of the transaxle. It’s hard to remove air pockets from this area without a vacuum fill tool.
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P ri u s I n v erter C ooling
Vacuum Fill Tool: (A.K.A “Air Lift”) The transaxle heat sink is near the top of the transaxle and the inlet/outlet pipes are near the center of the transaxle. The heat sink chamber can become air locked during service. A vacuum fill tool is the best way to ensure no air is trapped when refilling the system. Depending on the design of the vacuum fill tool, you may also need a cap adaptor.
Safety Equipment: Lineman’s gloves, CAT IV-rated test equipment, and other hybrid safety issues have been discussed ad nauseam in many publications and training courses to the point of crowding out more useful material, so I won’t torture you by repeating more of the same. If you are not already familiar with hybrid safety, please read the safety information in the service manual before starting work. The most important safety precaution is being sure you understand the system you are servicing. Asking and answering the questions, “How does this work?” and “How can it hurt me?” will provide far more for your
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safety – and diagnostic capability – than a set of rubber gloves.
Pump Diagnosis The most common failure for both the Gen 1 and Gen 2 is the inverter pump. There are TSBs addressing this and improved design pumps for both the Gen 1 and the Gen 2. Diagnosis of a failed inverter pump is usually pretty simple, but virtually any Prius diagnosis should start with a Health Check, if for no other reason than to establish a baseline. Even if you’re pretty sure there will be no codes when you start work, you’ll always want to check for codes post repair to make sure you haven’t caused any to set. If you don’t perform a baseline check, how will you know which codes you caused and which were pre-existing?
Gen 1: Inverter water pump failure diagnosis typically begins with finding a P3130, INF Code 346. P3130 indicates a problem with the inverter cooling system and INF
Always start with a Health Check.
When a P3130 and P3125 set together, ignore the P3125.
Code 346 specifies that the problem is with the water pump. INF Code 347 indicates trouble with the cooling fan. I assume the HV ECU logic uses the ICE coolant temperature to determine that the fan is at fault, but I don’t know this for a fact.
Sometimes there will also be a P3125, INF Code 264 – DC/DC converter malfunction, and a bunch of low-voltage-related codes in the ABS/VSC ECU, Transmission Control ECU, etc. Ignore these codes for now. When the inverter overheats,
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P ri u s I n v erter C ooling the DC/DC converter (part of the inverter) will stop working. The DC/ DC converter charges the 12V battery, like a generator on a standard car, so your customer may report dimming lights, the Multi Function Display (MFD) screen flickering, or similar “alternator-like” symptoms. The car may even stall and require a tow. The DC/DC converter will probably work OK once the auxiliary battery is charged and the inverter cooling system problem has been corrected. Once you’ve found a P3130, INF Code 346, a visual inspection is the first step. Is the coolant level low? Are any hoses kinked? Are the radiator fins blocked? If not, the next step is to remove the inverter reservoir cap, and check to see if the coolant is flowing. You should see a fair amount of burbling. If there is a placid pool of pink tranquility under the cap, check for voltage across the two-wire connector at the inverter pump with the power mode in READY or ON. No coolant flow + Battery voltage across the inverter pump = Bad inverter pump.
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If the coolant is still or barely moving, there’s a problem.
When the pump is working properly, you should see a fair amount of turbulence.
The inverter reservoir can become opaque as it ages. A flashlight is helpful when checking the level.
Simple huh? Flat rate diagnostic guys rejoice!
Use a seam splitter to slit the protective sheath, and then use piercing probes to check voltage.
If the pump is powered, coolant should be flowing.
If you pull enough inverter reservoir caps off, you may notice that some cars with no codes also have no flow. The right combination of driving style and ambient temperature may allow a Prius with a bad inverter pump to continue driving trouble-free. This common lack of flow was one of the problems with the Gen 1 inverter bleeding procedure found in the service manual. Half of the time, the coolant flow was imperceptible or non-existent, which made following the bleeding instructions an endless loop, repeating steps (H) through (L) forever. You may also run into inverter
Piercing probes can save a lot of time and can often provide more reliable contact than back-probing, but always remember to repair any insulation holes and rewrap the harness. February 2010 | MasterTechnician Online
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P ri u s I n v erter C ooling
pumps that work intermittently. Flat rate guys may stop rejoicing when they encounter one of these.
Gen 2: The Gen 2 Prius has a different trouble code for the inverter cooling system -- P0A93, INF code 346 -but the diagnostic procedure is the same. TSB EG001-07 recommends that the inverter pump be replaced if no trouble is found during the standard testing. I’m not sure if this is an acknowledgement of the possibility of an intermittent failure, or an indication the old pump design lacks pumping capacity. Regardless, after checking the basics, pump replacement is the best option.
Inverter Gen 1 TSB EG023-07, which addresses the improved inverter water pump, also contains a “Plan B.� If the inverter pump flow seems adequate, and the code set while ambient temperature was above 90 deg. F., Plan B is to replace the inverter with
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Above: 2001-2003 Prius Inverter
an updated unit. If the inverter is out of warranty (8 years/100K miles), this could be a pricey repair for your customer. If the inverter pump is original, it makes sense to do your best to confirm that the problem is not caused by an intermittent pump failure. In fact, replacing a seemingly good pump with an updated unit might be a gamble your customer is willing to take. A few hundred dollars wagered on a new pump may save a few thousand. Then again, the money may buy nothing more than an assurance that an expensive repair was really needed.
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P ri u s I n v erter C ooling
Below: The redesigned Gen 1 inverter pump can be identified by the silver colored bracket.
Crash! Collision damage to components of the inverter cooling system is common. The inverter radiator is obviously in harm’s way, but the inverter, inverter pump, hoses, and even the transaxle can be damaged when a Prius is smacked in the front. Frequently, the damage is subtle and will go un-noticed during the body shop repair. You may encounter a 78 MasterTechnician Online | www.mastertechmag.com
Prius that has been repaired and on the road for months with low coolant and a P3130 or P0A93. Inverters can be cracked by impact, or sometimes the inverter reservoir outlet will crack where it enters the inverter. If the reservoir cracks, the inverter can be pressure-tested using a single-hole stopper and 16mm cap before spending money on a new reservoir. Tire leak detection fluid
The rear inverter mounting point is circled.
(soapy water in a spray bottle) works great for this. Only use a regulated air supply, not shop air. While not directly related to the inverter cooling system, you may encounter the following during cooling system repair: When the inverter is hit, the rear mount bracket is often bent. If you remove the two front mounts and the inverter goes “SPROINGNGNG!” as it jumps up a few inches, this is probably the case. The ABS/VSC actuator is mounted to the rear mount bracket. If you’ve never done one, plan on it taking at least six hours. This job cannot be done without the Techstream since you’ll need it for ABS bleeding and calibration.
A new hose clamp won’t fix this one. February 2010 | MasterTechnician Online
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P ri u s I n v erter C ooling Transaxles can be damaged at the coolant fittings. Sometimes body shops will figure the leak is coming from the hose, install a hose clamp
and then assume it’s fixed. I’ve seen post-collision-repair leaks from these fittings twice now. There’s only one “right” fix: a new transaxle, an option that’s bound to be unpopular with your customer or their insurance company. Toyota hoses are of superior quality, so it’s unusual to see a leaking hose even after eight years of service. However, hoses do get damaged during collisions or repairs. You may need a mirror and some patience to fully inspect all of the inverter system hoses.
Conclusion Most techs will have no trouble diagnosing and repairing the inverter cooling system, provided they have a Techstream and vacuum bleeding tool. The common mechanical failures are covered by TSBs, and collision-related surprises shouldn’t present much of a challenge since this system has more diagnostic capabilities and less complexity than a standard ICE cooling system. This hose was pinched. 80 MasterTechnician Online | www.mastertechmag.com
(See Page 82-83 for Replacing an Inverter Pump instructions.)
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P ri u s I n v erter C ooling
Replacing an Inverter Pump on a Gen 1 Prius
1. Remove the inverter reservoir cap, then remove the inverter drain plug in the transaxle.
3. Here is the hidden headlight nut. The other two fasteners are on the top of the headlight housing in plain sight.
2. Remove the bumper cover. This is necessary because the bumper blocks access to one of the headlight bolts. Most of the bumpers fasteners are obvious, except for the two nuts hidden in the wheel well.
4. There is a retaining clip in the inner lower corner of the housing. Just pull the headlight housing toward you to release it.
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5. Once the headlight is out of the way, the pump is easy to access.
7. Install the inverter drain plug and torque it to 29 ft/lbs.
6. If you are planning to reuse the hoses, use a hose pick to separate the hoses from the inlet and outlet.
8. Use a vacuum fill tool to fill and bleed the system.
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to your tech buddies so they can sign up for their free subscription too!
Inside the Insider Five Ways to Limit Liability By stepping out into the business world, every step has exposure. While you cannot stop people from suing, you can insulate your business, personal assets and wallet from most liability if you take some steps to protect yourself. (Turn to page 1)
Human Potential The mind is a strange and powerful tool. Psychologists tell us some very interesting things about its function. First, 90% of its activity is subconscious.
Volume 1 | Issue 1
Five Ways to Limit Liability For Business Owners By David V. Allen, Esq.
y stepping out into the business world, every step has exposure. While you cannot stop people from suing, you can insulate your business, personal assets and wallet from most liability if you take some steps to protect yourself.
B
First, incorporate or form a limited liability company.
(Turn to page 1)
In Times Like These Small business is the skeleton of our economy. Businesses like ours. (Turn to page 3)
This requires that you file articles of incorporation, or in the case of a limited liability company (LLC), articles of organization with the Secretary of State, or whatever governmental office handles business filings in your state. Once you incorporate or form an LLC, you must hold your business out to the public as a corporation or LLC. This means
Sole Proprietorship It does not matter whether the individual is just getting started in a new business or is a twenty year business veteran this question comes up on a regular basis. My answer to this dilemma has always been the same, it depends. (Turn to page 6)
MT Business Insider Pricing Matrix Businesses are based on percentages, but customers look at prices. How do you reconcile your business’ need to make a decent profit margin on parts with your customers’ need to pay a fair price? (Turn to page 8)
ASE Certification: The Competitive Advantage One of the most powerful influences on choosing a repair facility is word-ofmouth recommendations from family, friends, and neighbors. Existing customers usually recommend a business based on trust and positive past experience. (Turn to page 10)
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Continue p.2: Five Ways
Human Potential Using What You’ve Got by Greg McConiga
he mind is a strange and powerful tool. Psychologists tell us some very interesting things about its function. First, 90% of its activity is subconscious. Let’s define that. “Sub,” as in “below,” and conscious, as in an individual sense of recognition of things within or without oneself. 90%! Think about that. It says if -- IF -- you are 100% in control during your waking hours, the very best you are capable of achieving is still only 10%.
T
It’s generally agreed that a human’s learning ability is physically unlimited. Remember that a scrap of brain tissue no larger than this “o” can store more information than a computer the size of a Honda. Now, consider that an average person’s brain weighs about three pounds. How many ounces of yours do you actually use? Continue p.5: Potential