I don't think my girlfriend would appreciate being called 'the staff'. Although that isn't going to stop me from calling her that anyways.


This morning was the combo breaker. The car worked perfectly and even the throttle functionality wasn't weird.
I went through the engine bay and pulled every lead and ground wire i could find and cleaned them, then pulled every fuse and relay and replaced them with new.

 

It has been a week and the car hasn't acted out at me once.

I put 1100 miles on it over the weekend as well.

 

MH,

Well done and, like a lot of Jag things, you’ve fixed it... and don’t know exactly what you did that fixed the problem.

Hope you have many more happy miles with the car.

 

Nice. Hopefully a win.

 

Woke up today to a text message from the module repair guy saying that the module that i sent back to him was not the module that he loaned me.

It had a warranty sticker from another module repair company and had not gone through his diagnostic or repair. He wanted me to send him his module back and that i "must have bought this one from another company and still have the one i sent you laying around somewhere".

I have only ever dealt with him and I had met him personally and taken that very module from his hands and stuck it in the car the last time we worked together on this. I had noticed that it didn't have his sticker on it and thought that it was a core he got from a customer and that he tested it and it passed testing so he gave it to me to try in my car.

Apparently what had actually happened is that he accidentally gave me a customers core that was non tested non repaired and then it got to wreak havoc in my car for six months or so.


So that explains why i was having such bad luck with abs modules.

The first one that I was sent was the wrong model #, since the car came with the wrong model # abs module installed when i bought the car.
The second and third ones I was sent had the wrong software installed on them.
The fourth one that I was sent was the correct model and software revision, but had intermittent errors cause it was an untested customer core.
The fifth one just magically worked because we finally had a repaired correct hardware and software model module installed in the car.

 

Are you comfortable mentioning his business's name, this does not seem right.

 

I have several times in this thread already.

I don't think i should name and shame him though, at the end of the day even though he made a mistake that caused me to waste a lot of time on the car, he still did so for free and offered his own time to try and help troubleshoot the problems of the car.

If you want to chaulk the mishandling of the module up to a human mistake, everything apart from that he went above and beyond to help me fix my car.

 

Understand. Hopefully if he gets other business, learning has happened on his side.

I have some strong suspicion that some of the ABS issues that keep showing up on this forum are vendors who don't quite know/appreciate the details required to make what they are selling work (and which one is appropriate for which vehicle), and it's likely going to be rare that someone has a CAN logger to notice it's spitting out the wrong heartbeat signal, for example. Thus far, this might be you and me.

 

He has been repairing these for years i believe. He does the ecu, door modules, abs, seat modules.

The reason i got the modules #2 and #3 both with the software problem was because it took me a month, and multiple attempts of using the wrong software to convince him that there were software differences that caused incompatibilites in these modules.
He still really didn't believe me until he bought a 97 xk8 himself to try modules on and discovered that what I had been saying was true. And then every time since that he has talked about it he keeps saying it as though he discovered this fact and that it is a secret that no one else knows ( including me who told him about it ).

He also was telling me about a huge stack of abs modules that he thought were broken until he got this 97 and now magically they all work on the 97 car and all of his tested good modules don't work on the 97 car.
So he had been stockpiling good modules that had software on them for the earlier cars and was just throwing them in a junk pile i believe.

 

Exactly the problem. He's going beyond repairing someone's module to providing modules, and he does not appear to understand the software (and/or maybe the hardware) issues...

Also a tad disorganized?

 

Yeah, basically.

 

I know this is an older post, but I am having the same P1637 code problem after re-soldering my own ABS module and all the crap to get it back in. CEL (P1637), ABS light on, no speedometer, "no tccm" light on, and a new one "INCORRECT PARTS INSTALLED". BS! I used my own module, not a replacement. Anyway, tried clearing code, doing hard reset, all the typical stuff.

WERE YOU EVER ABLE TO SOLVE YOUR P1637 PROBLEM, pass smog, and can you drive the car WITHOUT FEAR?

 

My problem was compound.

I bought my car in a non working status and found paperwork that indicated that it had been bouncing around auctions with different jag dealerships trying to scoop the car up cheap and fix it quickly to turn a profit.
Naturally none of them were able to fix the car and would just pawn it off to the next party that thought they were smarter.


The first of my issues was that the ABS module installed on the car had the famous issue where the leads needed to be resoldered in order for it to work again.
Unfortunately for me, once that ABS module started communicating with the car after the repair, it was quite unhappy.

After trial and error working with a repair shop and intercepting the CAN bus traffic, it turned out that someone had installed an ABS module with the wrong firmware.
Once I managed to get the correct ABS module on the car with the correct firmware, the car drove properly without fault for months and I managed to get it smogged.

Then the car brought back all of the same error codes but this time with a vengeance.
I had been reading up other people who had similar issues with the ABS module and this error code and found that some of them were reporting that their ECU was bad.
I remember inspecting my ECU at one point and noting that the capacitors had leaked a bit in the past and someone did a poor job of cleaning it up.
I sent the ECU off to the module repair guy and he fixed it and sent it back and the car has been reliable since.

 

^^ For some reason, the '97 ECMs suffer from leaking capacitors that can cause an array of seemingly-bizarre error codes. Your P1637 does list ECM failure as a possible cause.

Replacing these capacitors isn't difficult if you can wield a soldering iron, and the case comes apart without the need for a dremel Even if the caps are not the cause, it is a straightforward PM to replace them as it appears that many fail eventually, sometimes damaging the circuit board.

 

I wonder if Jaguar used Chinese-made capacitors during the first year of production, quickly realized the error of their ways in that particular application, and switched to Japanese-made capacitors for the remainder of the XK8/XKR production run....

 

that was denso’s job not theirs

 

Thank you. I have read your thread(s) of replacing those old caps on the ECM, but my first ignorant question next is: WHERE IS THE ECM, and is there a thread on the R&R of it? If I can get it out......must be easier that that damn ABS module.....my brother is a 50+ year pro at replacing circuit bard components. He might be a bit reluctant for a few more days since I just spent a week in the hospital being crushed by COVID attack.

But since most other things don't seem to work, and the list of warnings and idiot lights keeps growing, I'll try whatever I can before taking the car to a Jag shop.

So,where do I start?

 

First, thank you for your diligence in reporting on your ABS mod nightmare and the short-lived solutions. I am going to try some of your driving, shutting down, restart, driving attempts. First, I have to get some Universal Yellow because my expansion tank apparently drained out while the little overflow tube was disconnected (didn't ever see but a few drops around the open end of the line which I kept elevated). Obviously, the sensing of low coolant keeps those damn modules from saying all is "ok".

Gotta add some DOT4, too, but the reservoir looks pretty full and I only lost a few drops when R&R the ABS module. These cars are far too finicky!

 

It has been mentally what feels like ages since I had to deal with this so my memory is a little bit fuzzy, but I remember getting this Christmas tree effect of errors a few times after disconnecting and reconnecting the ABS module.
I can't remember exactly what I did to fix it, but I think it involved removing the abs electrical connector and reinstalling it, and then removing the battery terminals and letting the car sit in timeout overnight before reconnecting.
I wasn't convinced then, nor am I convinced now, that these Christmas tree errors are always more serious than just the car remembering that it was unable to communicate with the module for a brief period of time and telling you all about it.
Helping it forget about its troubles might help you forget about yours.

I also had to replace the battery in the car 3 different times through the course of troubleshooting my errors to find a battery that hasn't given me Christmas light error codes.

If the problem persists after checking connections and letting the car reboot, then maybe I would heed the warnings and start double checking that the soldering work you did to the power pins was successful, and that the ECU is undamaged.
The ECU can be found in the passenger side of the engine bay mirrored where the brake booster would be on the drivers side. It is a grey box with tons of wires coming out of it. The transmission controller is sitting right in front of it and might need to be removed to get enough room to remove the ECU. It is a 5 minute job with just a couple torx bolts holding the cover on the compartment.



I agree completely. A lot of people are going to blame it on electronics making the cars more complicated and thus more to fix, but in reality what has happened is that the companies are installing the absolute cheapest parts possible in the electronics that not only fail prematurely due to shoddy PCB design, but also have shelf lives that ensure the cars become nuisances to keep around longer for more than 10-15 years or so. We are just buying cheaply engineered cars because it is more profitable for the company.

 

Jon, From what I've seen, the caps in the 97 and 98 are the same: - made by Nichicon, and have the same values and type #s. Whether Nichicon was a victim of the 'bad cap' debâcle( see https://www.badcaps.net/ ) or there's something intrinsically different about the '97 ECM, I don't know.

Either way, electrolytic caps are not forever as their characteristics and efficiency degrade over time. A visual inspection may not show any clues, or they can fail spectacularly, as in greenforest56's case (long):
https://www.jaguarforums.com/forum/x...4/#post1776440

The ECM is, as Mad Hatter describes, under the cover in your passenger side false bulkhead. Here's ASI's description for its removal:
https://www.autoecu.com/jaguar-xk8-e...-instructions/

You may find (as I did) that the retaining screws are 'tamperproof' rather than torx, and that once you have the cover removed, you need to first pull the TCM out of the way.

There are seven caps that should be replaced:- one of which is hiding under the daughter pcb.
I posted the part #s here:
https://www.jaguarforums.com/forum/x...6/#post1806456
Cost is ~$6.

I can't promise that this will solve your issue, but it's good PM for the early ECM units.