Hello and abs help please
 

Hi all, please help :icon_mrgreen:
I am a lady mechanic with an XK 8 a 1998 with the dreaded abs problem .
I have had the car scanned and have a can bus failure code of 1637 :confused:

I have done all the usual , repaired the module myself, and then sent it away and had it professionally repaired .

I have also replaced both front leads to the sensors and checked all the pickups etc, I have no wheel sensor failure codes.

After the repaired module was fitted all worked well for three days , then is the car stood running , to warm it up , the dreaded abs , traction light came on, restart the car and it was ok.

It's got progressively worse again and the symptoms now are these,

Start the car just abs light on , drive it for a few yards and all lights go off, then after a differing but usually very short ( minutes) the abs / traction failure message comes up.

I know this is a common problem on the xk8 but I feel with all the effort I have put in on mine it's more than just the normal problem !

I do feel it's a can bus problem so can anyone tell me where the connectors I need to check are .

Thank you so much
Hugs from the uk x Rachel

Oh , I should of said does anyone have a link to an abs wiring diagram please
Thank you

Hi Rachel and welcome to the forum. What is the resting voltage (ignition off) across your battery? A tired battery can sometimes cause chronic ABSitis.

Rachel:

The P1637 is a CAN/BUS problem error code, and it can be very hard to diagnose and get to the bottom of. It's one of those issues that can be multi-faceted, and require a good, experienced Jaguar mechanic to solve.

The CAN is like computer wiring that communicates between the ABS module and the Engine Control Module (ECM.) It can be a resistance problem, polarity problem, ground problem--and, it's complicated. It can also be an ECM problem.

P1637 (and P1643) can also physically be a pin problem--where the wiring is not getting a clear signal. That's when connectors are disassembled and cleaned.

There is a set procedure to follow diagnosing CAN/BUS problems, but it's not something most individuals have the technical knowledge to go through.

I suggest you search "P1637" in the Thread section for more reading.

I'm also a victim of this illusive code.

Thanks bamaman , jaguar themselves hav spent time , and a lot of it on this car for a previous owner.
I don't want to give up so easily ( that's a girl thing) so its going to be off checking the wiring for me ;-)

Any idea where the can lines go ?
Thank you again.
X Rachel

Before you spend a lot of time trying to find a CAN bus problem, you should reset the code and see if it comes back. It is quite common to have a spurious CAN bus error, especially if the car has been worked on.

Also if your battery voltage is under about 12.2 volts with the engine off, it is a prime suspect for the ABS problem.

ABS/Traction Control
 

Rachel;
Should you want to get into wiring diagrams:
Go to FAQ
Scroll down to Electrical Category (alphabetical)
sub heading - Find your Electrical Diagrams & Information -open
this will open Translator -Super Mod
there is a Link: Captain Jaguars Electrical Diagrams, which will open a myriad of Jaguar models in which you will find the XK8 by model year.

Thanks tried that but this code wont reset .
Battery ok
thanks again .

Hi all an update , ...............
Thanks to this wonderful site and the very kind person who has the wiring diagrams I have been able to check the can network in particular the can wiring between the Abs , then transmission , and engine control unit.

My original code was 1637 which is a loss of can communication between the Abs and the ECU, which goes via the transmission ecu.

I have checked the can wires , and connectors between all three control units and they are 100% , no amount of wiggling or tugging will show any sort of problem , resistanced check out to perfection.

so where do I go from here ???? is the abs module still faulty ?????
I would get a second hand one but its a very odd part no ending in AF , and I have never found one .
A new unit is £900 sterling so its an expensive mistake if its not the fault.

Now i could be barling up the wrong tree here , but I am wondering if the last link in the can network , the dashboard (instrument display) might be faulty as it did once throw up a "low oil pressure " warning.

do or dont I replace the abs module ?????

I will keep updating this post as hopefully in the future it will help someone else.

X Rachel

Welcome to the forum Rachel, your tenacity tracking down your problem is encouraging!

There was a post over the past couple of days in which it was recommended to disconnect and reseat the dashoard multi-pin connector as a potential solution to a communications problem. It is fairly easy to do (no, you don't have to remove the steering wheel per the JTIS instructions - there's a thread on that, too, here) - be sure to disconnect the battery beforehand.

Keep at it!

Rachel,

Not sure I can help but will try. This link will take you to onelines and OBDII codes related to that year car Jaguar elecrtical, OBDII and specs This link is for ABS troubleshooting Jaguar ABS Repair In it you will find a troubleshooting chart for a 1999 MY car. I see that yours is a 1998 and I am not sure it has the same readings or pin configuration but it should help. You say that the ABS module was replaced, was it done by Jaguar? If not was it a model that is compatible with your car? Not sure but I have been told that not all ABS modules are interchangeable. I hope this helps.

hi the abs module was "reconditioned" by an independant jaguar specialist , but having spoken to them I feel they just soldered the motor pins .

The unit when replaced did work for a couple of days problem free.

I have tried a pump /module off another XK8 with a differing number , but that did not work at all.

thanks everyone for your help , can systems they are such a pain !!!!!

It is an opportunity!

Get additional information on your module. It is possible that it was repaired and it did not hold.

the abs problem
 

hi rachal. well I hate to be the badnews bear but that abs problem is mostlikely not abs or traction control at all. That is the beginning to the end of that transmission as you know it. They start off as this misterious abs traction control problem, but in the end that tranny need to come out and be rebuilt. Its got a 16 wire connector on it and it start sensing a mechanical problem within, something like a ring breaking in the tranny or something but the computer cant communicate that thru the can bus. This must be taken apart and inspected and then fixed. Good luck if you find someone to do this job for a good price its worth it. just take it out yourself. i figured while i was at it take the engine out as well and update tensioners and check out that rear seal also.

-1 on above.

Don't go off the deep end and assume it's a transmission until you have a professional independent Jag mechanic properly diagnose the problem.

There is a specific flow chart on CAN/BUS problems that can be followed that tells where the problem is. It's just a little too technical for most inexperienced shade tree mechanics (like me) to follow.

That's why I was saying this can be a multi-faceted problem. It can be a module problem, a connector problem, a wiring problem, a component problem (engine, transmission). And if any one of these items is not working properly, it can throw out the code. The problem could be very minor (connector), or could be major.

And, they'll all run you nuts until the problem's found. Sometimes, you've just got to shell out the hard earned money for peace of mind.

++1 Take your time be systematical and eliminate the obvious.

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Go Rache......we're rooting for you :icon_beerchug:

The guys here will be happy to jump in and add to the post with any snippets here n there that may prove useful.
You might try asking one of the techs to jump in and help out too by sending a pm?

Good luck......

hi guys after spending all day saturday checking the can system I can (sorry about the pun ) defo say the can network contacts and loom are ok 100% checked and tested.

the gearbox fault , well its just had a reconditioned gearbox , yes I fitted it (with a freind ) , the Abs fault was there before and its still there now, so I don't think it's the transmision (gearbox).

I did code read the car after I checked the wiring i now have a left front wheelsensor thats not comunicating to the abs module as far as its(the module) concerned , so i checked the wheel sensor for resistance and signal at the module plug and its all ok !

so module off and I have posted it to be checked again.

I never give up ,lol

thanks everyone ;-)
hugs from the uk x rachel

Use a spray contact cleaner be sure the connection is tight and apply a little di-electric paste on your connectors it should help. CRC makes both products and you can get them at AutoZone.

Is there a way to trick the computer into thinking the ABS and Traction control are running normally until such time that you can get it sorted.