Got in my 2001 XJR this morning when the amber ABS light came on along with the following warning ASC not available, Trac not available, when I switch the ignition off, and re start the car all the warnings go away, but after about 15 minutes driving they come back, has anyone any ideas what the problem could be?

 

Any recent "events" or work done on the car ? There will be fault codes, so get these read out.

BTW this forum is for the aluminium XJ saloons from 2004 onwards, so try posting in the X308 forum, you will get a better response.