Took XK8 to local shop the get AC charged. As I drove away saw the ABS warning light was on and the message ASC NOT AVAILABLE and TRAC NOT AVAILABLE. Can anyone point me to potential problem

 

This is a very common complaint, with many possible causes. The best way to handle it would be to have the codes read by a dealer or independent with Jag specific test capability. If you want to try to solve it on your own, the following is a starting point:

http://jagrepair.com/images/AutoRepa...heet%20XK8.pdf

 

The problem went away. I'm going to clean wheel sensors but based on posts found here I'm probable going to need a new ABS control unit.

 

Make sure your battery is fully charged and in good condition- a failing battery can trigger all sorts of fault codes and messages.

 

If it is faulty, the problem is often the solder connection to the abs pump, code C1095. A new abs module is several thousand dollars, while having yours repaired is under $100.
At this point you may want to consider having the codes read so you can make the proper decision. It may be nothing more than a failing wheel sensor cable or the pump connection.

 

I'm not dismissing all the fine suggestions you've already received. I had the same issue, hit, even a small bump, and the ASC and Trac Control, as well as "fail safe" mode, with reduced performance would ensue. OBD codes indicated throttle position sensor, and mass air flow sensor. While still in the process of investigating the OBD issues, I cleaned the wheel sensors. Simply cleaning the sensors ended all other issues immediately. In fact, even the OBD computer reset on its own, and the Check engine light went out, after about a week. It's now been over a month, and there hasn't been a recurrence of any kind. So, if it were me, I'd clean the wheel sensors first, and then address any issues that remain. Good luck!!