On my 1996 VdP when tracking down a throttle sticking problem, which turned out to be a simple dirty throttle body, I upset the ABS and traction control system by disconnecting leads around what I assume is the cruise control with the engine running. With everything reconnected the car runs and drives fine but both the ABS and Traction dash lights are on and not resetting themselves after several days driving. I've tried disconnecting the battery but that didn't help. Is there a simple way to reset these or do I need an OBDII scanner to do it? Thanks.
Correction - sorry, disconnected leads that caused the upset were not to the cruise control but to some mechanism that the throttle cable passes through on its way to the throttle body, the mechanism is attached to the ABS/Traction control block.

 

There is a dampening design where the light should not show on this system until 3 faults detected and to reset the car has to go above 12 .5 MPH

But in your case I don't know yet

There is a hard reset procedure beyond what you did with the battery disconnect and yours is a US model

There is the bracket the cable is fixed into as 2 options A and M ( the letters you may not see after the years )

 

https://www.jaguarforums.com/forum/x...budget-249892/

 

You have encountered the dreaded throttle relaxer!! It operates to momentarily close the throttle when the ABS sensors detect a loss of traction, and restore the throttle position once traction has been restored. The cable attached to the throttle pedal is attached to one disc in the relaxer, and a cable runs from the throttle body to another disc in the relaxer. These discs are normally connected, and operate in unison, until a loss of traction is detected, when the throttle body disc is released momentarily, before being returned to its original position by an electric motor, and "reattached" to the throttle pedal disc. A throttle position sensor is attached to the top of the unit to keep track of things.
Should any fault be detected with this unit, it will trigger the ABS/TRAC FAIL warning light, which will not clear until the fault is remedied, which it sounds as if this is where you are at.

The first thing I would check, assuming the connector to the unit is securely attached, is the cable adjustment. As well as the normal considerations when adjusting a cable, it seems to be critical that the at rest or "neutral" position of the discs is within tolerance. It would be possible to have the cables operating satisfactorily from a mechanical perspective across a range of disc positions, but electrically, the range of acceptable positions is much narrower. There is a procedure specified for the adjustment, which I dont have to hand, but google is your friend. You havent mentioned your idle speed, but incorrect adjustment of the cables can play havoc with it. Ask me how I know......!

The good news seems to be that the units are otherwise robust, although I guess like everything else, they cant last forever.

 

Thanks - now I understand what it is and that is undoubtedly what I've messed up. I had pulled its leads with the engine running. Also with the engine off I had pushed the cable between the throttle body and the relaxer back into the relaxer an inch or so, and the cable came off its track and hung. I thought I'd eased it all back exactly as original without disturbing anything, but maybe not.
I've searched U tube and my workshop manual for how to reset this relaxer but can't find anything, you seemed to indicate you'd seen something in the past and any pointers would be highly appreciated.

 

​​​​​​https://www.jaguarforums.com/forum/a...stment-pdf.pdf

Copying links is not my strong point, but hopefully this will work!

 

I had the same issue but if you follow the document above you should be able to get everything back to normal. Remember oncce you get things back to normal. Reset the fault and take it out for a drive before checking everything again. It took me a little while before getting it perfect

 

Gents - the link from each of you was enormously helpful, many thanks, and as soon as it warms up here I'll try it. Other than following the adjustment instructions, is there anything more needed to reset it, such as an OBD-II device, or does it automatically reset itself? And as a follow on question, what document did these instructions come from? I have a CD with service manual and various associated documents but none of them have this.

 

Yes you will need to reset it at least I had to. Mine was a different error code than most. Mine was 1495. You know I can't remember. I think it came from the new documents that were added to the service manual. I am sure @Parker 7 can help. He is pretty good at documentation

 

My 96 does not have the 2 adjustment turn barrels but CDMA's 97 does so the doc probably came out after 96

The turn barrel doc was provided by someone else

May have been page 41 to 43 of the new year model supplementary document or new year model updates

 

Problem solved, but not in the way I expected. I hadn't mechanically disturbed anything in the throttle relaxer, so followed the adjustment directions only as far as checking how everything was set. And everything was where it should be. But in the process of checking that, and also that both the electrical connectors were properly seated, I spotted that the leads to the electric motor on the bottom of the throttle relaxer were shedding their insulation. The plastic insulation on these leads is somehow faulty, and flakes off at the slightest touch leaving the wires to the motor bare. I carefully taped the wires so they aren't shorting or touching any other metal, and bingo both the ABS and traction controls reset and their warning lights on the dash went out. Hopefully the fix will hold, and I'll organize a more robust repair to the wires with heat shrink tubing. Thanks again for the relaxer adjustment instructions, that helped save the day.