I thought I should give you this info: https://www.jaguarforums.com/forum/x...t-38112/page4/

 

The GOOD news is that the shop only charged me for 1/2 hour of diagnosis.

The BAD news is that they could not do ANYTHING to help. They think the ABS MOD is "bad".....suggest I find a replacement or possibly send it out. Hmmmm....OK, I guess it's possible even though it was working intermittently before I took it out and re-soldered the two power pins. They said they cannot make ANY communication with the module. I will ask from WHERE THEY WERE TRYING TO COMMUNICATE when I pick up the car. I don't get it.

They cannot communicate or reset/flash/reconfigure/reprogram the module. (?) Back to square one.....or maybe square 4 since I've already identified as much as they did when I scanned before. They said they found NO C code for the ABS module or pump. wth??? OTH: the "INCORRECT PART INSTALLED" light on my dash is gone. woopie!

Bob says he has a '97 module. I hope it's a good one.

 

My module has been saved by Module Repair Pro, Van Nuys, CA. $100 plus shipping both ways, but it was worth it. I don't know exactly what they did, but everything works now. NO MORE IDIOT LIGHTS. No "WRONG PART INSTALLED" messages. No DTCs. I cleared whatever codes might have been there from before, then plugged everything in and powered up. Great! I drove around and put 34-40 miles on straight and very twisty roads at various speeds. Speedo/ODO works again.

 

Glad to hear it!

That is the same shop that my "interesting" experience was with earlier in this forum thread.
I think he learned a lot working with me on my vehicle.

I never got an email notification in the past few months that you guys were still commenting on this thread, so i never ended up checking. Sorry for disappearing on you.

 

It seemed like all the ABS module issues were over, and all the lights gone for good.....but not so fast.I described what has happened in my thread "ABS module from Hell" or something like that. Long story short, all my lights and issues came back. My driving was limited by a necessary PAS pump R&R that took weeks to accomplish. Got that done, put about 150 miles on to reset the emissions computers, and then I guess I messed up this finicky bitch by leaving my headlights on while visiting a store. Up to then I had no battery issues since the ABS module replacement.

Anyway, when I returned to the car and started it, the ABS, CEL, and E-brake lights came on. I took it home, did a code read and got P1637 and P1111. So, cleared the codes and tried again. It got worse: now I have the "Incorrect Part Fitted" crap and a P1000 code. Somewhere in between reading and deleting codes I did disconnect the battery and do a hard reset of the system. BAD IDEA! That set the emissions computer back to mile "0". I've driven a bit, deleted the P1637 code again, and the CEL, ABS, and the rest come right back when I start the car. I'm so pissed I have not tried driving it far enough to see if any lights go off because I HAVE STILL NOT BEEN ABLE TO GET MY GD EMISSIONS TEST and sticker COMPLETED SINCE ALMOST A YEAR AGO! I'M BACK WHERE I STARTED.

I called Gino at Module Repair and he suggested the ECU needs rebuilding. It might, but how do I really know? I have babied this car for 14 years and put countless hours and thousands of dollars into it. Right now I don't even want to look at the damn thing. But, I cannot just let it sit, so must get it running properly to either enjoy or sell.

What do you think about the ECU issue? Is it worth $200 + shipping to experiment and find out?

Ken

 

Is it worth trying? Absolutely.

To directly answer your question about how to tell whether your issue is in the ECM, it is relatively easy to pull the ECM out of the vehicle, remove a few screws and visually inspect the board. You don't need to be an electronics expert to do a cursory glance at the board before sending it off, when these fail, they often fail in very obvious visual ways. You might open the board to find places that look like they have experienced localized fire, with the electronics board appearing to be a cookie wafer that someone left as a charcoal in a fire for a few hours. You might also find that a capacitor ruptured and be left with spots on the board that should be clean copper that have corroded and are a nasty white/green.

If you still don't feel confident in taking these steps, that is perfectly fine as well, because they are largely for your own interest unless you are knowledgeable enough about electronics to either determine fault or dismiss fault purely by looking at the electronics board. The caveat here being, if it looks like a warzone you can be pretty confident it has issues and needs repair.


My car did something similar to what yours did before I rebuilt my ECM. I managed to get a few hundred miles on the car without any issue, and then one day all of the problems came back with a vengeance, ironically it happened the day that I went to take it in to get it smogged.
After I rebuilt the ECM the car magically worked again and the only issues I have had with the car have been when the battery inevitably went bad. My car went through about 4 batteries each year. I had to drive it across country at the beginning of the year and I replaced the battery before I left for the trip and it made the 2,000 mile journey in about 34 hours and ran like a champ the whole time.

 

Don't clear codes unless you first have done a fix you are reasonably sure actually is a fix!

Even then, they self-clear if it truly is a fix...

Every time you clear the codes you're also clearing the emissions stuff!

(That's how the laws in the USA and many other countries are.)

 

Thank you! Obviously I have been doing it wrong. Come to think of it, I remember Gino saying I should be able to go straight to the emissions test because the repair rto the module cleared everything. SIGH!

Ken

 

Thank you. That makes me feel a bit better. My retired electrical and advanced circuitry engineer brother says he'll inspect it if I take it out. He has way better tools that I do.

Ken

 

2- I pulled the ECM, took it to my brother and his shop. He opened it up and I have to say this Denso ECM is the most immaculate circuit board system I have ever seen. Beautifully crafted and tightly laid out. We couldn't find any physical evidence of breakdown or leakage anywhere. But of course, that doesn't mean something couldn't be wrong with some part of it. There are hundreds of resistors and almost as many tiny capacitors and transistors. "Tiny" is the operative word.

It puzzles me though, that I would have the exact same symptoms as before, and the repair of the ABS module had solved the problem entirely. How would that have been the ECM if the repair of the module fixed the problem? The fact that the P1637 code means a loss of communication in the CAN might mean the harness between the module and the ECM is somehow intermittent. But even that wouldn't explain several months of code and light free driving.

My son, wife, and brother think I should pull out the ABS module and send it along with the ECM. If it's the ECM, fine (if it can be fixed). If the ECM is OK, I don't want it to be sent back and I still have the problem....and then have to send the module. The only problem with this plan is how much I hated taking that thing out and reinstalling it.

Is there any way to test the module or the ECM for general functioning either in the car or out? It seems like the principle of signal in has to create signal out should have a way to test that. Of course, it's a Jaguar so I must be dreaming.

Ken

 

Yeah that is what I was experiencing as well. I had months of problem free driving after replacing my abs module, that is because half of my problems were that I had the wrong abs module installed.
Then the problem came back because the abs module was not the only thing that was wrong in my car. The ECU was also bad and that needed to be repaired as well before the problem was resolved for good.

The same symptom but two different problems independently causing it simultaneously.
I also was almost guaranteed to get the codes if the battery was not absolutely perfectly charged, city driving was not enough to keep the battery charged and the batteries would ultimately test bad and get replaced about every four months.


I tested the wiring harness in my car religiously at first as well, thinking that would assuredly be the cause of my problems. I only ever stopped thinking that the wiring harness was the problem whenever I hooked up a CAN bus logger onto the network to intercept the network traffic and crbass taught me how to read the messages and we found out that the software on my abs module was not sending the right messages, thus the ecu was convinced that it couldn't communicate with the abs module.

 

First, I want to thank you for your very helpful information about this all-too-common problem. I wish there was a centralized analysis/R&R/repair/follow-up source that we could glean without having to search over and over and communicate with the right person. This forum is a great step in the right direction, but it is full of so many cars. users, and issue discussions that it takes longer to get an answer that makes sense than it does do do the repair. Yeah, I know "use the search function". If only it were that simple. The search sends me to so many irrelevant threads and posts that it really takes starting from scratch and hoping someone will reply. It would take a lot of time and reprogramming, but a better cataloging system would really help. OK...enough of that.
I am going to unbox the new Autel M619 scanner I got after my module came back, and I think I'll re-connect the ECU and do anther comprehensive scan. I'd like to see what other codes are down in there before I send out the ECU.

 

I don't mean to be critical of you, because you are making very reasonable reactions to the situation that you find yourself in, but the reality of the situation is that you seem hesitant to pursue the options that are likely to resolve your problem quickly/efficiently.

The error message that you are getting indicates that there is a communication issue between the ECU and ABS module.
From an abstracted frame of reference, you have three parts that are implicated IF this error message is to be trusted.
The issue is likely in either the ECU, the ABS module, or the wire harness between them.

A brute force method of solving this problem would be to swap out all three implicated components with known working parts.
It is an unreasonable proposition due to price, and how much of a pain in the *** it is to remove the wiring harness.

This is why the first thing I did was whip out the multimeter and spend a few hours testing the integrity of every wire between the ECU and ABS modules to the best of my ability.

It is still expensive to source known working parts that you can just swap into your car to try and resolve this with trial and error of permutations of parts.
I remember the module rebuilder offered to send me working tested parts to swap into my car so that I wouldn't have to bite the bullet of paying for used parts in unknown condition.
You might be able to try and convince him to do the same, I believe he took a security deposit from me and refunded it afterwards.


I am normally the type of person to be critical of anyone that attempts to solve a problem by swapping parts until a problem is resolved, but this is likely the best self diagnostic tools that you have due to how nefarious of a problem this is.

Does this forum have smart enough members to create hardware and software that would be capable of just plugging into your car and figuring out your problem? Potentially, crbass and a couple other members have been slowly contributing to the knowledge pool that would eventually allow for something like this to exist. However, I don't think anything like that will ever exist due to how small our community is, and how much effort it would take to create.

 

You have been great with me. Sorry for being a PITA. My apologies here for duplicating this post so I can get some answers, but I find it takes more than one person to solve these issues. Maybe that's how Jaguar keeps techs employed and busy. Here is is:


THE LATEST!

I sent the ECU off to Module Repair Pros. They went through it, got it back, hooked it up, reconnected the fully charged battery....SAME LIGHTS AND CODES.

QUESTIONS: 1- I only turned the key on and off and on, then started the car several times. The P1637 and P1000 codes are still there. I have NOT driven the car. I have seen so many posts telling me to clear the codes, not clear the codes, disconnect the battery, don't disconnect the battery, etc.
I can drive the car if that is the key to clearing the DTCs. I have cleared them with a good scanner, but I think it doesn't really get them out of the memory until it reads that the problem is corrected. Is that right? And, that takes driving the car through its "drive cycle", correct?

So, the last 2 times I have had to reset the emissions sensors, I had to drive about 200 miles. That's what I was trying to do when it all failed again a couple of months ago. I got up to about 150 miles and POOF! Does than mean the codes were still counting up again and it blew up because of too many
"failure" impulses? I think those are "Pending Codes", right?

So, is my next step to drive the car to see if the ABS, CE, and Brake lights go out? I think that doesn't take very many miles....but I still don't have a 2022 tag on the license.

Ken

 

The emissions drive cycle this code are separate things. The 'drive cycle' for P637 is ignition on > 5 seconds. So, the if the car still thinks it's happening after 5 seconds, something is still happening.

So, the alternatives
- ABS fragged, but had fixed (?)
- ECM fragged, but you've had it fixed (?)
- CAN bus down completely, but that would cause other problems
- CAN bus down (perhaps intermittently) between ABS and ECM (that's still a potential source), check continuity on the wires, incredibly likely to be at either end, but you can yank on the middle too
- Madhatter's problem (someone sent you the wrong ABS,ECM, or sent you a repaired ABS, ECM with the wrong ROMs)
-Etc.

You have no way to assess the repairs independently, so everything seems tricky unless you're up for buying another 97 XK that's working.

My next move would be to look at the ABS response with a CAN analyzer and see, in detail, what ECM and ABS think about the ABS (about 60 seconds worth of data would tell you whether the ABS is there, talking correctly to the ECM, etc).

Unfortunately, I'd be happy to do this, but I appear to be several thousand miles from you. If someone local has one you can use, happy to look at the data.

 

I'm not usually the guy to do this but... As a start https://m.yelp.com/search?find_desc=...=Rocklin%2C+CA

 

Thanks. I know a few of those, but have only tried one (McCaffreys). They said their $billion analyzer couldn't communicate with the ECU and wanted something over $700 just for a rebuilt ABS module to try to make the connection. OTH, they are supposed to be the best at solving Jag problems. I will call some off the others and be specific.

THANKS!

 

Thanks.

ABS "fixed", ECU "fixed", I am pretty sure I did the forum-suggested CAN to ABS module probe for continuity and the CAN or ABS to the analyzer port inside the car. The resistance readings were good.

I think my Autel ML619 analyzer is supposed to be able to read CAN. I'll re-read the instructions.

Thanks!

 

If the P1637 went away for quite a while but is back I'd be suspecting a wiring/connector problem next. A slightly loose/dirty pin, chafed harness, etc.

The PCM (aka ECM) hardly ever fails - but of course they can (usually due to water getting in & when you look it's obvious). Yours sounds OK especially as you sent it out.

I don't know enough about the ABS module to comment on yours but as it's also been out it's likely OK.

(I expect you know P1000 is a status code that at best won't go away (by changing to P1111) until the P1637 is gone for several drive cycles.)

 

@oldjaglover You aren't being a PITA, I had to lean on others here to get my problem resolved, I am happy to help pass it forward.

Just a sanity check.... Have you checked the battery voltage, it should be absolutely fully charged or these cars have a habit of throwing codes and doing all kinds of evil things.
When my battery would drop even the slightest voltage it would throw codes and go into limp home mode and flash christmas tree lights on the dash.

I got in the habit of charging the batteries in my car every so often, even though I was regularly driving it.
Then every few months i would take the battery in to get it tested and sure enough it would fail testing and the parts store would hand me a new one.