TECH INSIGHT

Welcome to Tech Insight created with the support of the IVS 360 OEM-Trained Master Technicians at OPUS IVS and TMD Friction to whom we are very grateful.

Here we highlight some of the more common recent faults that our partners have come across in their workshops and of course provide you with the appropriate fixes.

We are always reviewing our content and please feel free to get in touch if you feel that there is something you would like to see in future editions of SMTA AutoINSIGHT.

PROVIDED BY

RANGE ROVER EVOQUE 2016MY TO 2019MY DIESEL AND PETROL. FAULT CODE B11DB-87

TECHNICAL CASE BY ROB MILLER

Situation: The battery charge warning lamp may be displayed in the Instrument Cluster with Diagnostic Trouble Code (DTC) B11DB-87 stored in the Body Control Module (BCM).

Cause: This may be caused by a blown Battery Monitoring System (BMS) fused harness.

Symptoms:

• B11DB-87 Battery Monitoring Module A - Missing message

• Battery monitoring system circuit open circuit, high resistance

• Battery monitoring system internal failure

• Auxiliary junction box internal failure

INITIAL CHECKS

A pin-point test is available to help diagnose DTC B11DB-87. For additional information, refer to: Battery (414-01 Battery, Mounting and Cables, Diagnosis and Testing).

1. Check the integrity of the battery monitoring system connectors. Repair as required.

2. Check the battery monitoring system control module circuit between the BMS and the auxiliary junction box. Repair the wiring harness as necessary.

3. Check the battery monitoring system circuit for open circuit, high resistance between the BMS and the auxiliary battery positive terminal. Repair as required.

4. Clear the Diagnostic Trouble Code(s) and retest. Then perform routine - Power Supply Service Mode Diagnostic

5. If the fault persists, check and install a new battery monitoring system control module as required.

6. Check the LIN circuit between the Battery Monitoring System Module and the Gateway module.

7. Should also check LIN control unit power and ground circuits.

CIRCUIT

C1DC05A: Module-Battery monitoring system

C1DC05A-1 Green-White LIN circuit to the Central Junction Box

C1DC05A-2 Blue-Orange inline fuse fed from the positive terminal of the battery, this gives the BMS a true battery voltage direct from the battery and can monitor it sending out a signal on the LIN wire to the GWM gateway module this then transmits a signal to the generator via a private LIN between the GWM and the Generator.

The BMS is ground through its fixings to the negative post of the battery then off to a chassis earth point.

FURTHER CHECKS:

Ensure that the power supply from the battery is present on the Blue-Orange wire.

• No, suspect inline fuse has blown and will require a replacement subharness

(Contact dealer or supplier for VIN specific part number image above)

• Yes, carry on with next check

Ground Supply is present and good, if not clean BMS mating face and body/ chassis earth point.

LIN CIRCUIT

This is on the Green-White wire usually 1-volt below battery voltage. This goes from the BMS to the Central Junction Box CJB as previously described.

Measure the voltage at the BMS connector C1DC05A-1 Green-White and then compare this reading to the one at the GWM.

The GWM connector is known as C1Y122: Module-Gateway Location Behind passenger side of Instrument panel on the Left hand inner lower A post red connector with 20 cavities. Remove out locking cover taking note of insert position relative to the GWM and refit it.

Locate the Green -White wire at C1Y1223 Measure the voltage here does it match that of the BMS connector?

• YES, suspect BMS unit faulty,

• NO, resistance pulling down the voltage. Disconnect connectors and load test it.

No voltage present, check continuity and load test the wire if open circuit suspect a break in the wire examples of such break as below in the attached images.

In this instance they had to remove scuttle panel and the abs module bracket, lift abs module up out the way!

MERCEDES-BENZ:

Models affected: Mercedes-Benz - all models with electric cooling pumps

Issue / Symptoms: Yellow coolant warning on Instrument cluster and possible fault in the PTCU (power train module) “The rpm of component ‘Coolant pump’ is too high” following the coolant system being opened.

Cause: The fault can be caused by air in the coolant system allowing the pump(s) to run dry and over speed.

Repair Guidance:

The coolant system must be drained, filled and bled as per WIS instructions (group 20) using all the required tools. Do not replace the pump, they have a “dry run detection” that turns them off to prevent damage.

Tmd Friction Issues Advice On Brake Fluid Changes And Checks

Scott Irwin MIMI, Head of Technical Training at TMD Friction offers best practice on brake fluid, advising on when it should be changed and the differences in grades of brake fluid.

Affected Vehicles: Renault Clio 3 (2004 - 2009) – All variants with K9K engines and JA5 and JR5 manual gearboxes

Modus (2004 - 2009) – All variants with K9K engines and JA5 and JR5 manual gearboxes

Symptoms: Vibration, humming sound, or judder through the vehicle when stationary.

Additional Information: Can be felt in neutral at idle speed through pedals dashboard and seat base

Possible Causes: Upper engine mount failed

REPAIR STEPS

1. Check and confirm vibration.

2. Whilst sitting in the vehicle raise the engine RPM from idle and see if the noise stops.

3. Visually check upper engine mount (see picture).

4. Using an assistant get them to manipulate the mounting by adding pressure to it using a lever bar in the areas shown.

5. If noise stops or changes pitch remove and check the mounting.

6. If any fault is found, consider replacement of the mounting.

7. Once the new part is fitted confirm noise has been corrected.

PARTS REQUIRED: Upper engine mount (8200140431)

HOW OFTEN SHOULD BRAKE FLUID BE TESTED AND CHANGED?

The process of testing brake fluid is straight forward, and exact boiling points can be identified easily using a brake fluid tester. The dangers associated with driving a vehicle running on old brake fluid can be life threatening, and this test needs to be seen as a standard check that is critical to the health of a vehicle. Brake fluid deteriorates over time and is not greatly affected by distance travelled. Always follow the vehicle manufacturer’s recommendation on when to change the brake fluid.

WHAT’S

The

DIFFERENCE BETWEEN DOT 3, DOT 4, DOT 5.1, AND ESP?

The original grade DOT 3 was the standard brake fluid for many years, and it still is in some territories, particularly in North America. However, DOT 3 grades tend to suffer from steep boiling point decline over time, and DOT 4 fluids were developed to counteract this. They contain polyglycol ether esters, which chemically bind the water and dramatically slow the decline in boiling point.

DOT 5.1 fluids are a development of DOT 4, having not only higher boiling points, and retaining them even better than DOT 4 in service, but also having a much-improved viscosity at low temperatures.

Technicians should always use the fluid type specified by the vehicle manufacturer to avoid mixing each variation. It is possible to mix some glycolbased fluids but never DOT 5, as this is silicone based.

IS DOT 5 THE SAME AS DOT 5.1?

No. DOT 5 is silicone-based, and DOT 5.1 is glycol ether-based. The reason for this is historical; the DOT 5 standard was originally written for silicone brake fluids that have a much lower tendency to pick up water. However, it wasn’t long before conventional fluids were developed to meet the same standard –these were designated DOT 5.1.

Unless the customer is a classic car driver, for most purposes conventional fluids are better. Silicones have some major advantages (not least their lack of hygroscopicity) but this is more than outweighed by some major disadvantages.

Silicone-based fluids are hydrophobic as opposed to hygroscopic and will not absorb water. Therefore, DOT 5 is considered to have a very long lifespan and is commonly used in vehicles that need to be stored for long periods of time, but ready to go at the drop of a hat such as military and classic cars.

DOES BRAKE FLUID HAVE A SHELF LIFE?

It does. It is hygroscopic (it absorbs moisture from the atmosphere) and this happens to a small extent, even when packaged in closed bottles. As the product absorbs water, its boiling point declines. The magnitude of this decline depends upon factors such as the storage conditions, the thickness of the bottle, the type of closure used, the container size and material and the grade of brake fluid.

When brake fluid is in a vehicle, water will find its way through microscopic pores in brake hoses, seals and joints. Even when it’s on the shelf, unopened bottles can absorb moisture from the atmosphere and should not be kept on the shelf for long periods of time.

So, for brake fluids stored in a temperate climate, a shelf life of approximately 18 -24 months from the date of production can be expected. Under tropical conditions, the equivalent period would be 12 months.