Hi, I first off apologize if this has already been answered but I've looked and looked. At first it was just my abs light I continued to drive it until one day the speedo went to 0 and the hand brake light came on, a few minutes later on my way home it started to work again but as I pulled into my drive way again the speedo went to 0 and the handbrake light came on. So I un hooked the battery thinking it might help but in the end to no avail, now it says improper part fitted speedo is on 0 and the eBrake light is on.
From all my searching it seems a faulty abs module could trigger the p1637 so I pulled it out today going to be opening it and re soldering it tonight, however, I started the car without the module and it still says incorrect part fitted and the speedo issue is still present.
Has anyone ever experienced this pesky speedo/handbrake issue? And is it possibly related to the p1637? (Note cruise control never worked before all this began) please any help at all would really be appreciated.

MCJ

 

Mystery cars are usually ignored.
Make Model Year???????????????

bob gauff

 

It's a 98 XJ8L, sorry about that I thought I had provided that information. Thanks for the quick reply though!

 

P1637s seem to be reaching epidemic proportions. It is a CAN bus communication error and can be caused by many things.
Once you get your ABS reinstalled, you can clear your codes and then see what comes back. With the ABS module out, your car is going to throw a lot of bad codes that can muddy the diagnosis.
There is a lot of info on the forum about the P1637 as well as other CAN bus failure codes and how to approach finding the cause.
Post what you find and the forum members can help direct you in the right direction.

 

I talked to my jag mechanic and he suggested that the hand brake speedo issue was a separate issue than the abs and that they are two different problems. The only problem is that he is booked until Jan so he couldn't help me much besides say that they're different problems.
After I pulled the abs module the other day I started my car and no new warning lights came on. I have reinstalled and still all the same problems are present. One thing I did notice though is the message on the dash that says "in proper part fitted" continued to show even though the abs module was out. Does anyone know any way to find out which part is in proper. I never installed any new parts and these messages came on while I was driving so I'm thinking maybe a wire harness or a relay but do you have any idea which or where I should look?
I looked over the fuses involved with the components all seemed fine I've also been checking connections and cleaNing them with electrical cleaner all to no avail.
I know one thing for sure is If I can pinpoint which part is in proper I could defiantly isolate the problem.. Thank you all so much for your help, I can't express how much it's appreciated.

MCJ

 

What is apparently happening, from the code and from your symptoms, is that the communication link (the CAN bus) between the ECM (engine control module, the TCCM (the transmission module), and The ABS is loosing its synchronization (the token). That could be due to a failure in any one of those modules or the wiring itself. The CAN bus wiring is three wires and can be traced using the diagrams if you want to check the connectors for corrosion or loose fitting.

I do not believe your best bet will be to begin changing modules and I cannot don't know how folks can give advice as to where to get help if your only location ID is "victoria".

 

My location is Victoria BC Canada

 

Please do two things: update your location to include BC, Canada; fill in your signature block to show car, model, and year. I hate having to travel to the top of thread for essential information (and nobody ever goes to your new member post).

 

OK thanks for the input my location is already updated to Victoria BC and I just updated my signiture to show my car. I have read the new members board I'm just waiting for 10 posts to create my garage. Thanks for the advice.
Does anyone have any ideas on how to locate the improper part hpwever?

 

Hi RollaJones,

In case you don't have these documents:

You can download the 1998 XJ Electrical Guide here:
http://www.jagrepair.com/images/Auto.../jagxj1998.pdf

The 1998 Transmission Diagnostic Trouble Code Summaries is here:
http://www.jagrepair.com/images/Auto...tem%201998.pdf

This Technical Introduction provides some clues as to how the ECM, TCM and ABS interact:
http://www.jagrepair.com/images/Auto...ansmission.pdf

This document explains the transmission control system:
http://www.thejagwrangler.com/upload...on_control.pdf


Cheers,

Don

 

Awesome thank you very much Don, I'll be taking a look through those today.