Mark, man without replacing parts now, I am not sure what to recommend. you could buy a new sensor, and replace either the Left or Right to see if you can find the offending one. I really thought the scanner at a dealer can tell you which wheel (sensor/module) is affected. Is this not correct? I wish you luck buddy.

 

I had a 99 XK8 with failsafe mode message come on while cruising the freeway. I limped into a parking lot and shut it off. A little while later I was able to start and drive it again for a few miles before the message appeared again and I lost power. Had it towed to my independant and he put in a used throttlebody with the sensors on it for a fraction of a new one. It worked forthe fraction of a newone before it went bad also. I had the dealer put in the upgraded throttlebody replacement the second time around. The problem was solved for good. I also had a problem with the traction control which gave me the message- stability control ABS failure . You can unplug the ABS module at the left front of the engine compartment. There is a place on the east coast that rebuilds electrical components like the sensors on the throttle body and the stability control module. BBA Remanufacturing Inc. Find them at www.bba-reman.com . You can still drive the vehicle with out traction control while it is off being repaired. Good luck

 

Are you saying that after you replaced the link lead and cleaned the sensors you got both front wheel codes, or before you replaced the link lead and cleaned the sensors you got the codes? ABS/TRAC faults will not cause engine failsafe mode though several faults that cause engine failsafe mode will cause ABS/TRAC faults. Have the codes checked again preferably while the fault is happening or shortly after. Brake switch faults will cause both problems and are notoriously hard to diagnose because the code will self clear after several good brake pedal switching events. Down and dirty check when the failsafe fault is occuring check the brake lights and if they don't work you found the problem but a key cycle can reset the system and the brake switch may work fine at that point, keep pressing the pedal on and off and if the lights ever fail to come on the switch is faulty.

 

I am also having trac control and failsafe problems. About 14 months ago I was getting this error with the ABS warning lights coming on. I had to replace a computer board for about 2 grand and my shop cleaned the throttle body.

Approximately 14 months go by with no problems (Although the car is only used about once per week). Suddenly getting trac control and failsafe again without the ABS warning, but with the check engine light. The car can be restarted and everything is fine for another 2-30 minutes of driving. The problem seems to occur after doing a little highway driving followed by stop & go city driving.

Bring the car back to the shop. This time it is the throttle body. Order a rebuilt throttle body from jagbits. Have it replaced. Go pick up the car, which is running a tiny bit rough. Up on the highway about 3 miles from shop and back into failsafe mode with restricted performance. Pull over restart and car is running great (no roughness). Drop it back at the shop and I am at a loss for what to do next. I like my mechanic and think he is straight, but I always like to have some knowledge when the phone call comes.

The car is a 2000 XK8 with just under 70000 miles. Any thoughts appreciated.

 

I'm also having the same problem - ABS light illuminates together with LCD message: "Trac Control and ASC not available". It happened twice last month. After stopping the car and re-starting, all seemed fine. I'm just back from a 2,100-mile roadtrip to Berlin from Dublin, and all was fine until the last day when the problem re-appeared twice in the one day. There seems to be no pattern as to when it presents itself. I'm asking my Jag mechanic to read the ECU codes and troubleshoot, but I am conscious of the lack of consensus on this issue, i.e. ABS sensors, cables, ABS module....

 

You can't fix cars with opinion, which is why there is no consensus. The facts are that there are several common fault areas with this system, the front sensor leads and the ABS electronic control module being the most frequent sources for the illumination of the warning.

Stored fault codes will help identify the source. The intermittant nature of your warning suggests that it is caused by a sensor lead fault but that is only an opinion and, barring some good luck, won't fix your car. The sensors themselves are reliable, and I have never seen a fault cured by merely cleaning them.

 

Still having problems. Changed the Throttle body with a rebuilt part from Jagbits and did not get 5 miles from the shop before the problem re-appeared. The car is back at the shop and I am currently waiting for news. This has been a frustrating experience.

 

I picked up the car earlier today and put about 30 miles on it with no incident. I am hopeful the repair took. I also wanted to give kudos to Gary at Jagbits.After I spoke with him about my continued problem with the rebuilt throttle body he spoke to my mechanic by phone and seem to have diagnosed and fixed the continuing problem together. I am not the most mechanically inclined but teh problem involved some type of switch within the throttle body. Gary definitely did the right thing by me. Now I hope I am not jinxing myself by posting.

 

We don't either Jkrub!