Hi All,

I am a long time reader of the forums and always found it a treasure trove of information. Currently I'm working on a 2003 XKR with a number of issues and I would greatly appreciate some insight. I normally work on the classics so I am a bit out of my depths. I've pulled the following codes:

• Communication failure DLC/VCI ABS Module
• P0706 Transmission range sensor circuit range performance
• P1774 CAN Timeout gearshift
• P1798 CAN Transmission control module / instrument cluster circuit malfunction
• P1799 CAN Transmission control module / ABS control module malfunction
• P1797 CAN Transmission control module / Engine control module malfunction
• P1637 CAN Link engine control module / ABS control module/ Circuit malfunction / Network malfunction
• U2523 CAN Message Timeout from the engine control module

The symptoms slowly got worse. A few weeks ago I got a DSC malfunction message which went away after a few minutes, no further issues. A few days ago the Gearbox fault message popped up. Now the low brake fluid message also joins the party, while the reservoir is plenty full.
When I reset the codes with the engine running, all seems to be fine. Gearbox shifts through all the gears, sport mode works etc. When I turn the engine off and try to start it again, all the messages return. However since today I can't communicate with the abs module anymore.
I've changed the battery for a fresh one just to be sure, no change.
I am leaning towards a fried ABS/DSC circuit board but love to hear your suggestions. Thanks in advance!

 

The ABS on one of mine required the resolder on the circuit board. I'm no expert, but I think one fault in CAN can give other errors. I'm sure an expert will jump in.

 

If you are getting CAN problems, the first thing to do is measure the resistance across the CAN High and CAN Low lines at the OBD connector - it should be about 60 ohms with the ignition off. The image shows the pinout looking at the connector:-



This is the first basic step to diagnosing CAN issues. If the ABS module is disconnected from the bus, you will get a reading of 120 ohms.

 

Sounds like my car when it decided to turn me down.

I measured the CAN bus forth and back and it took a while before i could get my head around it. (the can bus is an two lead bus that is terminated in the ABS in one end, and in the instrument cluster in the other end, in between, other users are piggybacked on. If any component communicating on that bus is shorting, the bus will fail. Troubleshooting can be really time consuming, but try the simple things first. If the car is a good runner that slowly sort of starting to make trouble, there is a good chance that it is something not to difficult to deal with.

-In short, my way to clear everything up;
1) New battery. (for good measures and a good starting point)
2) Replaced generator (old, cooling duct was missing, so it most likely over time got overheated electronics inside -> unstable voltage regulation caused the gearbox to throw failure code)
3) Replaced both switches on brake pedal switch assy. (very small currents can leak trough and cause the classic brake light fail and DTC fail)
4) Gearbox plug full of oil, caused the gearbox not to be able to properly communicate with engine i.e CAN bus failed! Cleaned it out. (realized that there exist an replacement plug receptacle with new seals that can be replaced when you change oil and filter in gearbox).
5) Checked and cleaned ABS plug and any plug i could access really, including ECM. I found a few plugs with some oily goo in, most likely some 20 year old electric compound that gone off..

-With what i know nowdays, first check battery life with a battery checker, if its old, replace with a new good quality battery. Check the plug on the gearbox, and ABS unit, make sure they are clean. Check and carefully refit plugs on cluster. (if my memory serves me there was a bullentin on checking a solder joint on the cluster cirquit board)

After this ordeal, my car got cleared and i havent had any issues since.... well.. EVAP something shows up sometimes, and O2 sensor.. but i just clear those codes and drive on.. for now..

/E

 

As said above, a likely candidate is that the ABS wiring needs re-soldering. This is a known issue. There are 3 videos in this series where John Dee covers everything you need to know.


Richard

 

2002-2003 they changed the layout in the ABS unit contact, does the 2003 and onward have the same "solder issue" as the older ones?

Btw, has anyone tried (on the older ones with the two separate pins) tried to just heat thoose pins good and "float the solder" on the other side of the board in order to "resolder them" ? Just curious.. i mean, if the fix is to scarp or pry open the unit... why not try...

/E

 

Thank you for all the replies.
I've taken the following measurement from the DLC:
Pin 6/16 = 59,2 ohm. Battery disconnected
Pin 6/ground = 2,678 V. Ign. On
Pin 14/ground = 2,284 V. Ign. On
Battery is at 12,5 V

I've noticed that de gear selector lights only show the P,D,R,N but not the 2,3,4,5 when selected. Is this normal operation while a gearbox fault is active? Gear selector illumination is also in the CAN BUS I believe.

 

When gearbox goes to fault mode, it disconnects the electronic control. This happened to me at full speed on the highway.. a very loud "CLONK" followed by a "gearbox fault"... i just carefully, while at the same time dreaded the repair bill, drove straight home on "manual mode" so to speak.. at home, ->ignition of for a few seconds and back again, problem gone. That time it was the generator that had failed. The voltage has to be within a certain limit, outside that, the gearbox dont want to play ball anymore.
My CAN bus/OEBD issue was oil in gearbox plug though.
And yes, the gear selector is also on the CAN bus..

/E

 

That certainly looks like your CAN bus is connected ok at both ends. You might want to wiggle the connector around at the ABS module just in case there is an intermittent connection.

By the way if you have IDS/SDD you can see the live data in the datalogger which would tell you if things like the ABS module is communicating ok and what gear the car sees the selector at. For anyone interested you can also do that with a CAN sniffer, another handy tool to have.

 

I recall seeing an old post from somebody (Motorcarman maybe?) saying something to the effect that ABS solder issues are either rare or unheard of with the 4.2l engine.

 

I assumed that the OP had the 4.0 but you might well be correct with the 4.2.

Richard

 

I have not seen the same cracked solder joint issue on the 4.2L cars, but that doesn't mean it can't happen. On the 4.0L cars it eventually happens to just about every module.

Sorry to digress from Bussoman's thread, but I have had the same thought about touching the pump connector pins with a soldering iron to heat them up and potentially re-flow the solder joints, which are on the opposite side of the circuit board. But since every 4.0L module I have opened up had starved and cold solder joints on many other components in addition to the cracked solder joints on the pump connector pins, I've decided the best course is to remove the module, cut off the entire cover, and reflow and supplement every accessible solder joint on the circuit board, then glue the cover back on with silicone sealant. Modules repaired this way will generally last the remaining life of the car.

Cheers,

Don

 

Maybe an age thing.

It would be surprising to find out the soldering quality had suddenly improved to the point of no failures.

Z

 

What is truly surprising is the long period of time over which ABS modules made by Ate (Alfred Teves) continued to have the poor solder joints. At the very least, the problems existed in the late X27, XJ40, X300, X100 and X308 from 1987 to 2003.

Ate was bound to figure things out at some point. One major change was that on the 4.2L cars, the ABS/DSC module has just one large electrical connector, instead of having a separate 2-pin connector for the electric pump that could vibrate and over time promote cracking of the solder joints.

 

Being a relative newcomer to modern Jaguars I don’t know how long the poor solder joints have been showing up ? Did they take a decade to start the cracking, or was it even sooner than that?

Z

PS / does the hood / bonnet slamming down over the years of usage have anything to do with cracking ?

 

Of course, at this point, all of these cars are more than 10 years old, but my recollection is that I have repaired modules on several cars that were less than 10 years old, including on my '93 XJ40.

On the other hand, my '01 XKR and '03 XJ8 have only begun triggering the C1095 code over the past couple of years. I haven't repaired their modules yet, but it's on my (long) list of things to do.

 

Thank you all for the input so far.
I've sent the abs module to AC Tronics in the Netherlands to be checked. Within a few days they reported that they have not found any faults with the module and shipped it back to me.
I installed the module today and lo and behold: almost all the fault codes are gone..... I've check the car numerous times today but I can't get them to reappear. Which I'm glad for but also worried that I haven't found the underlying fault.
I'm left with two new codes which triggered the engine management light and I'm unable to reset:
- C1165 Wheel speed rear right input- Circuit Failure
- C1175 Wheel speed rear left input - Circuit Failure

Does anyone see a correlation here? I assume a faulty wheel speed sensor would trigger the ABS light and not the Engine management light, could someone elaborate on this?
It seems rather strange that both the rear wheel speed sensors go faulty at the same time.

 

Ive got exactly the same problem on my 03 xkr.
both rear wheel speed sensors and engine management light. Cruise unavailable also.
Checked all four sensors, done the brake light switch. Hope you can find the answer.

 

On my X308, it was the wire (piglet) connecting the right front wheel sensor to the ABS network. Needed the ABS code to find it. See #9 -- you need to be able to read the C codes to see which piglet is bad.