1999 Jaguar XJ8

My 1999 Jaguar XJ8 has 49,000 miles and has developed an intermittent failure of the ABS/Stability Control System. The indicator reads " STABILITY CONTROL FAILURE" and the ABS symbol also illuminates. The failure tends to occur after the car has been driven on a hot day, then stopped for about one-half hour, parked in the sun, and restarted. Once the failure occurs during a day, it tends to remain for the rest of the day (but not always). The failure always resets overnight and never occurs when the car is first started in the morning. We got the car to the dealer once when the failure was occurring (because ABS codes are not stored in the ECM), and they said the ABS code indicated failure of the ABS module ($1,300). This code can also indicate failure of the ABS unit $1,600). The service advisor noted that the ABS module can become " confused" and to recommended we ignore the failure as long as it resets overnight. I have tested the ABS unit (in the rain) and it works just fine. I've inspected and cleaned the four ABS wheel sensors. I'm guessing an intermittent of some sort in the ABS module. Any ideas?
April 3, 2006.

Electronics are funny that way. If it does it hot then a module problem is likely

Apr 6, 2006.
I have read posts on other forums that have had this corrected by removing the negative from the battery (in trunk) this resets the abs control module these cars have about 6 different modules for different systems and sometimes the connections can get corroded as well. The US market cars will not lose their radio codes when batt is disconnected.

Jun 28, 2007.
Hello, you have already determined your problem. The pump operated fine. That leaves only the module. Yes it is expensive to fix. Try to find a used one. They dont need to be programed. Just plug in and drive.

Sep 20, 2007.
Hi, I had this problem earlier this week, I was quoted 1000+ by the main dealer over the phone before he had even looked at the car.
What I did was remove the wheels and the ABS sensor is easily located, it has a 2 pin plug connecting it to the lectrics, disconnect it, get a multi meter and test the resistence of the sensor, it should be around 650 ohms, the lowest I had was 615 ohms and the highest was 658 ohms except for the one that was open circuit!
A new one from Jaguar is 147.95, a used one from my local Jaguar specialist was 20.
Apart from struggling a bit to get the old one out, it's was easy enough to replace.

Dec 19, 2007.