Yep, got the dreaded ABS light, Check engine fault, Traction control unavailable, low brake fluid warning and red Brake light, on my '97 XK8 coupe. Also have no Speedometer. So far, I've had the module re-built, cleaned and tested all four sensors and checked wires for continuity / Ohms. Checked and cleaned all underhood ground connections, and replaced the large ground strap from Body to engine. Checked grounds in trunk area.

What I've experienced since I had the module rebuilt, is that I can drive for several days with no lights, codes, etc. Then, out of nowhere, ABS comes on, then shortly after that check engine light starts to come on and off, along with the Brake Light. When this starts to happen, I also lose the Speedometer. I no longer get the low brake fluid warning since the module repair. If the Check engine light goes off, I get the speedo back ( most of the time). After a couple of on/off occurrences , the check engine light stays on, brake light stays on, and speedo stays off. Pulled codes, and get the ABS Chassis fault code, and the ABS DTC fault code. No codes for any of the sensors ( got them before cleaning). If I delete the check engine light, and unplug the ABS sensor, cycle starts over again.

I've checked the battery- it is three years old. At rest, after sitting overnight, and with no lights ( like trunk lights, etc) on, I show 12.45 V. When running, I see 13.5 - 14 v ( I'm using an x60 guage in the OBDII port).

I could live without the ABS if I had to, but not without the Speedometer. I'm thinking it's likely the ABS module is still faulty ( at least intermittently), but being a '97, it's a one year module and not easy to find (JLM20130, LJA2210BH, 10.0946-1004.3) . It may also be the battery, as I've read about a low battery condition causing issues. However, the small amount of testing I've done on the battery is inconclusive, and it's not a cheap part to just throw at the problem.

Is there something I've missed, or another alternative I should look into. Thanks for your collective wisdom on this- it's the last major hurdle for me to finish this restoration.

Just couldn't resist adding a picture:

 

That JLM20130 is kinda rare as it is the TRACTION CONTROL version for that year.
The JLM20129 (5 pipe-6 valve) will not work and I don't think a later JLM20556 9 valve will either but I have never tried it.

You don't specify what C (chassis) codes you are reading.
An actual code would help with the diagnosis.

bob

 

Chassis code I was getting is C1137, ABS / DCM Module. Also got P1637, which is the DTC powertrain code for ABS Fault. More info as of today. I went out and started the car, and the ABS light and Brake light were gone, as was the note for Traction Control. Only the Check Engine light remained. I cleared that code (P1637), and now everything is back to normal. Don't know why it would have cleared itself ( c1137). I suspect that after a couple of drives, it will all come back again.

 

Sounds like a CAN bus communication fault or the ABS CM.

The ABS Control Module seems to go 'off-line' at times. Could be the CM or a wiring fault.
Check the power and ground as well as the module connector.

You can also check the integrity of the CAN bus 'twisted pair'. The modules at each end have terminating resistors so the measured resistance should be about 60 Ohms between pins 6 and 14 at the OBDII connector. The INST PK is at one end and the ABS CM is at the other end.

 

Thanks for the info, and your patience with me.
I'll try and check that out tomorrow. Just went to the Autoparts store to have the battery tested. Half way there, the ABS light and Brake light came on, and the Speedo quit. A couple more blocks, and the check engine light came on, and the speedo came back. Stopped at the parts store and had the battery tested- tested good. Re-started the car, and Check Eng light, ABS light and Brake light all on. Speedo dead all the way home. BTW, when the Speedo goes out, I also lose speed info through the OBDII port ( X60). Still continue to get other info through the X60 ( coolant, voltage, ..) Does that help indicate Can Bus issue / no issue?

 

I can't imagine how an ABS problem is going to take out your speedometer so it must be some problem higher up the food chain.
When symptoms come and go, do they do it at the same exact instant or not?

 

Pretty much the ABS light comes on, and then the Speedo starts to go in / out- maybe 1-2 minutes working, then not working. Check eng light may come on, and then go off as well.

One thought that just crept into my mind- is it possible a PO tried to use an ABS module with Traction control in a car that did not come with it ( JLM20130 module where a JLM20129 module should have been installed) ? Car had the ABS faults when I bought it, with the JLM20130 module installed. No way to know if it was the original or not. If it matters, the motor has 5 brake lines connected ( not 6 as I have seen on other modules-maybe later years?)

Just jumping at straws, but I think the Speedo failure might be a key in figuring this out. I just don't know how the speedo and the ABS are involved. If the speedo (Canbus) gets it's info from the ABS module, then I'm leaning towards the module repair not being successful, or there may be a component in the module that is intermittent.

 

If you have 5 pipes (6 valves) you NEED a JLM20129.

Pull the ABS module off the valve block and see if the solenoids are matched to the CM.
The valve block should match the actuators in the module. (SAME NUMBER OF VALVES)

You might call the dealer and ask if your VIN describes your car as having TRACTION CONTROL.

There might be parts mismatch either way (correct module, wrong valve block?) or (correct valve block, wrong module?)

I'm guessing incorrect CM. There would be a left over pipe if the valve block was fitted incorrectly.

bob

 

The ABS module provides ALL the modules on the CAN bus with vehicle speed info.(including the INST PK)
No ABS CM, NO SPEED INPUT. The INST PK, TCM and ECM all want the vehicle speed info.

There is a cheap/dirty way to overcome the speed limiter of 250 KPH, just pull the ABS CM fuse and then drive full throttle until the car will go no faster.
You will likely need a GPS to know your speed. (The speedo will be inop)

bob

 

Sounds like we are getting closer. I'm assuming that I have a JLM20130 only because it says "CONTROL UNIT ABS + ETCS". The JLM20130 number does not show on the module, just LJA2210BH and 10.0946-1004.3. I crossed referenced those numbers at a repair module site to the JLM20130, plus the DIC keeps saying Traction Control not available ( I assumed I had it because of that message). Valve body is definitely a 5 pipe design- no other unused lines sitting around.

I'll pull the module tomorrow ( too hot right now) and check the valves.

 

Call me old fashioned but I thought that the vehicle speed information came from the transmission and the speed sensors on each individual wheel were just for ABS and traction control.
Apparently I'm behind the knowledge curve on this one, so I'll do what I often do in this situation. I'll ask some questions.
If the ABS module is sensing speeds of four wheels and they vary (which it's designed to take action to remedy), what does the ABS module use to calculate vehicle speed for the speedometer?
Basically, which wheel's speed is sent to the speedometer, or is it the average the speed of all four wheels? Or does the majority rule?

 

What's with the five pipes at the ABS module? I have six: Front in, rear in, and four out, one for each individual wheel. Which one is missing in the five pipe setup?

 

The 5 Pipe (6 valve) is on the left and the 6 Pipe (9 valve) is on the right.

Looks like someone installed the incorrect ABS CM on your car.
Remove the CM and check to see. It should look like the one on the left. (JLM20129)

 

Turned on the AC in the garage, and planning on removing the ABS control module shortly. I did find this website that repairs ABS modules , and they had a nice reference chart and pictures. The reference chart indicates that the control module I have installed is the correct one based upon the hydraulic unit part number (Second row of his chart). Pictures of the labels on the modules on his webpage show the words "Control Unit ABS + TCS" or "Control Unit ABS + ETCS" (hit Enlarge to see closeup). Can you help me understand the difference between "TCS" and ETCS". The module installed on my car shows "ETCS".

https://www.shop.modulerepairpro.com...XK8-97-ABS.htm

 

I found one of each (JLM20129 & JLM20130) and looked at the labels.
The JLM20130 is labeled ABS + TCS
The JLM20129 is labeled ABS + ETCS

I looks like you probably have the correct unit on the modulator valve block.




You need to keep diagnosing??

 

Thanks for confirming on the part numbers. I had my hopes up that it was the wrong module. Think my next step is to contact the company that did the repair to see what they might think. Might post up on the parts wanted forum.

Thanks again for all of the information, and for the very quick responses. This forum is really helpful, especially to a newbie.

 

Have you looked into the TSBs on Jagrepair.com? There were a number of issues related to bad soldering on the instrument cluster causing CAN bus problems. Seemed easy to check and repair with basic soldering skills. To my (superficial) knowledge, take the indicated VIN ranges with a grain of salt. The IC is not hard to remove (30 min?). Take advantage of the IC being out to replace all the (cheap) bulbs behind it.

Other option is that the repair to the power joints to the ABS board did not last, and the ABS board power still goes in and out.

Last option I can think of is that there is a bent pin in the connector. Or a pin that has a bad connection and needs to be bent a little for better contact.

Best of luck, keep us posted.

 

OK, checked the TBS list, but found none earlier than 2000MY that might have affected issue.

Decided to replace all three ABS fuses, even though they look good and test OK.

Decided to go for a test drive to see if I could re-create problem.
Started car- No lights, but DTC codes showed C1137, ABS Module
Backed out of garage, ABS light came on. 30 seconds later, Brake light came on. No Speedo, no cruise, no Change in ODO. Also, no Check engine light yet.
Drove 8 miles, 10 minutes. No change. Shut car off.
Waited 2 minutes, then restarted car. No ABS light. Speedo works, cruise works, ODO works. No Check eng light, no Brake light. Everything normal. Check codes- none.
Repeat 4 more times -drive 8-10 minutes, stop, wait 2 minutes, restart. No change-everything normal. Re-checked codes- None.

Too early to tell if changing the fuses fixed this, but it is encouraging. I'll continue to test throughout the week, and report back if I see any more failures. If by the end of the week no lights, I'll also report back in that changing the fuses might have been the cure.

 

Darn! Went for a couple more trips- no problem. Then, sitting in my garage, car not moving, ABS light and brake light comes on. Go for a short drive- no speedo, no cruise, but also no DIC for Stability control fail, and no red or amber lights. Go about 8 miles, and the Stability message flashes, the Amber light comes on, and then everything goes away, and it's all back to normal. Speedo works, cruise works, no lights, etc. Like it never happened.

For sure it's an random failure, and probably not caused by a loose wire ( since latest one went on when I was sitting still in park). Leaning very heavily toward just a bad ABS module, and may start looking for a replacement..... I sure hate Spark Chasing!

 

Just an update. Still having random issues. The company that repaired my module is "loaning' me a known good module for testing purposes, so should know more in a week or so.