Hello everyone,

This thread is intended both for discussion and for documentation.

Background: The vehicle is a left‑hand‑drive Jaguar XJR 4.0 from 2000. Some welding work has been carried out, including in the left front wheel arch next to the strut mount. During the work (took me two years in total, sigh) the battery was always disconnected. For the welding in the wheel arch I also removed all the wiring and detached all brake lines to and from the brake‑fluid reservoir. In addition, I unplugged the ABS control unit.

After completing the work, the car runs and is drivable, but the instrument cluster displays several warnings. Among them are “incorrect part fitted” and “low brake fluid” The speedometer is also dead.

I have a Jaguar IDS/SDD system and so I read the following fault codes:

• P1637 in the engine control module
• C1267 in the ABS module

Clearing the fault codes does not work - each time I turn the ignition back on, the codes reappear.
After a few ignition cycles, the ABS module also logs fault B1342.

When I try to re‑configure or reset the ABS module via IDS, the routine finishes with “successful.” The ABS module therefore appears to be (somehow) responsive via CAN bus.

So far I have checked:

• Continuity and resistance of all wires at the ABS module connector – no abnormalities found.
• All fuses and relays supplying power to the ABS module are OK.
• Wheel‑speed sensors are fine (resistance measurements of all four sensors is consistent).
• Ground points have been loosened, cleaned, and are in good condition.

Next steps: Next I will crack open the ABS module and look for cold solder joints or defective components on the board.

I don’t fully believe it’s a huge coincidence that the ABS module failed exactly at the moment I was working on the car; I suspect the faults are related to the repair work and/or the two‑year storage period. However, the fault codes actually point more toward the former scenario, even though I can’t imagine how the unplugged ABS module could have been damaged during the work.

Before spending €200–€300 on a used replacement ABS module, I want to eliminate every possible cause outside the ABS unit.

I’ll report back once I’ve opened the ABS module.

In the meantime, I’d appreciate any thoughts or suggestions on what else I should check.

Cheers, Alexander

 

Check the INSTPK for the recall.

 

Hi Bob,
Thank you very much for chiming in!
I had already come across this particular service action, but I dismissed it as unnecessary because my VIN is F23XXX.
Until now..I'll happily reach for the straw and will also examine the instrument cluster.

Cheers, Alexander

 

Thjere are a lot of good youtube videos. hope this helps

 

Hi everyone,

I wanted to give you a quick status report. Yesterday I removed both the instrument cluster and the ABS module again for further inspection.
1. Instrument Cluster
No issues were visible on the PCB. The solder points referenced in the service action are not present on my version of the instrument cluster (they seem to have been eliminated, as my VIN is F23XXX and therefore not anymore affected by the service action).

2. ABS Control Unit
Visually everything looks normal—no damaged components and, under magnification, no cold solder joints. My next step is to dive into the transistors, MOSFETs, and solenoid valves, and to study how to test them with a multimeter and/or an oscilloscope.

I think I’m onto something. I identified two SOT‑223 devices that carry the same marking but give different measurement results. The top side of each part is labeled “ON R07 BH‑16.”

According to my research, this is an ON Semiconductor part. “BH‑16” appears to denote the model/type, while “R07” likely encodes the manufacturing location, year, and week. However, the information I’ve found is somewhat contradictory regarding exactly what kind of component it is. Most sources describe it as a transistor, but ON Semi also lists MOSFETs with the BH‑16 designation.

I’ll dig deeper—I'm a complete beginner when it comes to testing electronic components, but I know that a multimeter’s diode‑test and resistance modes can get you a long way.
@Lear45: Thanks for the link. I already applied the C1095 fix to this ECU a few years back.

I’ll keep you all posted and will attach photos next time!

 

As you have IDS, I would be inclined to fit another used module. Do the solder job and back up and running - the now 'spare' module can then be diagnosed and possibly refurbished with new components, which would then question every other module out there as a possible old age fault you might just find for the rest of us - good work so far.

(I just noticed your other car is a Disco 3, mine is really testing me at the moment!)

 

Hi Sean,

thank you very much for your suggestion. I agree with you - if I were under a deadline, I’d probably do it that way too.

Right now the car is still sitting on blocks, waiting for me to replace the four injectors on bank A. Cylinders 3A and 4A aren’t running perfectly - especially injector 4A, which is also very noisy when cold.

While I’m at it, I can also tackle the heater pipes, water pump, thermostat, 3-way connector...and at the supercharger also the bearings and oil. Maybe the LH upstream O2-sensor too, as it's the last one left to replace.

Long story short: since the car isn’t drivable at the moment, I can afford to spend a bit of time on research about the ABS module.

By the way—what’s bugging you about Disco 3? Are you also active in the Disco 3 forum and have a thread there about your issue?

Cheers, Alexander