Our 2002 VDP has sporadically displayed the message "trac off" or and "ASC not available" along with the ABS light coming on for the past couple years. Usually on the next start-up or two the message went away and normal operation continued until the next errant message. Now the message has been persistent, prodding me to do something. I am guessing I have a problem in one of the rear wheel ABS sensors. Any other thoughts? What is suggested as the best way to track it down--I'm pretty handy and do most of my own work on our cars. I can't think of any contributing factors--like having run in deep water--that could cause it. The car only has 60K miles and gets driven maybe twice a week. Will appreciate any help!

I learned that it's not a big deal to remove the sensors and clean their contacts, but as cheap as they are online (all 4 for about $100) I would rather install a new one than wonder if I've done a good job of cleaning them. But I would like to isolate the one causing the problem. Comments?

 

The main culprits are usually the ABS wheel sensors, the ABS control module or the ABS pump itself. I would start by cleaning the wheel sensors and electrical connectors, making sure the wires aren't frayed then move to the ABS module if that doesn't fix the issue. I've run into this on 4 XJs and in my case it was always the ABS module. The soldering around the two main power posts tends to come loose over time, causing it to sometimes work before it fails completely. Their are a few companies that sell rebuilt ABS modules for about $300 but if you are handy with electronics you can attempt it yourself. I tried re-soldering myself once but ended up ruining the module.

 

get a scanner that can read C codes

C1095 pump motor will almost always be the module

 

The wheel sensors can be the problem, and they are very easy to remove and clean with a toothbrush, so worth trying first.





The ABS unit is a little more work, but but pretty easy to remove. As forum member anduha indicates, once the unit is off you can attempt a home repair but a professional fix is cheap, bench tested, and comes with a warranty.

I sent mine to these guys 3 years ago and was super-pleased. ($99 plus shipping)
https://www.shop.modulerepairpro.com/

(If you do decide to remove the ABS unit let us know and I can post a blow-by-blow walk-thru)

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At about the same mileage our 2000 VDP needed a rebuild for the ABS. I was uncomfortable removing the unit myself and had my mechanic do it and send it to:

https://www.upfix.com/product-catego...odules-repair/

The turn-around was fast and the cost was minimal. I had the mechanic reinstall it, too, as there is some brake line work involved and I am more of a steering wheel / throttle operator, not a mechanic.

Good luck!

 

Cleaning the sensors worked for me. There's no moving/wear parts in the sensors so not much to gain by replacing them unless they or the wiring is damaged. Cleaning is quick and easy to do and hard to do badly. My car has 60k miles and they looked like Carnival Kids pics before and after.

Cleaning the rear light bulbs and sockets got rid of the "check rear lights" warning too. 20 year old cars pick up a lot of grime.

 

I have exactly this issue as described by Cathead in my 2001 XJR. The car is at my dealer now to have the timing chain tensioners done and also to investigate these recurrent ABS/"Trac not available" warnings. I wish this thread had come up a couple of days ago!