If you did not manually disable the DSC when driving and the lights (as well as the message)came on, then its almost definitely a problem with the system. I had a similar problem with my '05 XJ8 about 2 months ago. Both ABS and DSC lights (and their corresponding messages) came on suddenly while I was driving. After shutting down the car andletting the engine rest for about 15 minutes, I turned it on again and the lights went out. Ibrought it tothe dealership but they could find the fault. They then decided to clean the ABS contact points at each wheel hoping that the problem would go away. However, it kept happening intermitently over the next few weeks until about 3 weeks ago when the lights failed to go off each time I started the car. I brought it in to the dealership again and was later told that a speed sensor switch had failed. Got it changed under warranty and so far the ABS and DSC lights have not come on.

Ipreviously had a XK8 convertible which had similar problems.But unlike my XJ8 the XK8 was diagnosed with ABS module failure and I had to change the complete module outside warranty. The repairs cost me almost US$2,000. I suggest the next time the ABS or DSC lights come on, bring the car to the dealership for a full diagnostic. Don't shut the engine down as this might kill lights and message and make finding the faultdifficult. Moreover, you would at least have prove that the lights came on without prompting! Good luck.