Driving down the road Fault code: Trac not available, then ASC not available, then Gearbox failure and then Fail Safe Engine Mode. Car quit !!! Waited on side of the road and drove home. Car has about 63k miles and other wise is in great condition. This has happened twice and I'm afraid to take it on road trips (what is was bought for).... So, since I'm new to this and not a great mechanic, and don't want to have a dealer charge me lots of $$$$ to fix, where might I start in trying to resolve the problem by myself ???? A neighbor has a lift and an old XJS he works on, but he is currently on the disabled list !!! I'm not a "spring" chicken but want to get this problem straightened out !!!
Thanks for your help
Bob, in WV

 

Some relatively basic things to do first :
- See if any fault codes stored (buy a reader or take to an indie with diagnostic equipment).
- Clean throttle body, MAF sensor and plug socket, Throttle Position Sensor plug socket (carb cleaner for the TB, electrical contact cleaner for the MAF wires/plug sockets/contacts)
- Check all ground straps for tightness
- Check battery condition

My guess would be throttle position sensor , throwing the engine into failsafe mode (the other faults occur by default). It happened to me once recently, I did the above and car has been OK since, but its only a possible suggestion.
Have you experienced slight "hesitation" recently when driving at highway speeds, like the car is hitting a very strong headwind...?

 

There is this ABS diagnose sheet, that I'm sure most V8 owners (mine is a 2002 XJR) are familiar with, titled:
"Jaguar XK8 ABS [HARD FAULT] check sheet" that shows a drawing of the "ABS Plug Front View" with the four wheel speed sensors connected to it, along with their resistance reading spec, plus a picture of the adjacent circuit breaker/relay box. It instructs to perform resistance readings from the ABS plug connections that lead out to the harness that leads to each of the four sensors. So, my question is, from what exact point do you take these readings. I mean, I can measure resistance at the sensor itself, and I've successfully done that, but that only verifies the sensor, itself, but how do you include the whole harness' electrical integrity from the ABS module (i.e. continuity/resistance) if I cannot access the "beginning" of the circuits from the ABS module? In looking at the device location, I can't see how you can gain access to the "ABS Plug (Front View)" with all those brake lines actually in the way. Again, this is a 2002 XJR.

Any help is welcome.

Thank you.

 

In the center dash there's a "Track OFF" switch, what does it do when you switch its status? Is it possible to just switch the ABS system OFF and just drive the car without it until whatever issue is taken care of?

It would sure be ideal if the owner was given the right to choose between using or not using the system. Sometimes, even when it is working normally, it can be annoying, such as when you drive out of a driveway and your rear wheel just catches a little of the higher sidewalk curb and drops to the pavement, causing a temporary loss of traction, and when you try to accelerate your way out of the oncoming traffic, guess what? It won't let you do it and you're a sitting duck, making proximity traffic that was otherwise far enough if it wasn't for my car's shortcomings, hit the brakes before they hit you and after they curse at you... I mean, what a pain, I can certainly do without that, or I wish that I could at least switch it ON and OFF as my decision.

I wonder what happens if I just pull a relevant circuit breaker? I guess that I can try that but actually no hopes...

Cheers,

 

OK, my 2002 X308, 4.0 litre has about 4 times now shown
"gearbox fault"
"trac not available"
"asc not available"
"fail safe engine mode"
If I turn off the engine, it refuses to start until the engine cools down, some 10-15 minutes.
Thoughts, please?