OK, so we drive from Albuquerque to Denver no problem. Drive around for three days, no problem. Leave Denver Sunday and DSC Fault displays, plus red AND yellow lights. On freeway I-25 middle of Denver Sunday morning, engine still running but no power. Accelerator does not respond. Flashers on pull over on shoulder. Turn off ignition, restart, everything OK all the way back 450 miles to Albuquerque.
2003, 4.2L, 54K miles. Any thoughts before it goes to the mechanic?

 

My first thought would be to have the codes read with a scantool that can interface with the full range of Pxxxx (Powertrain), Bxxxx (Body), Cxxxx (Chassis), and Uxxxx (Network) codes and post them back here.

You could spend some time but save some $$$ that way.

Graham

 

https://www.jaguarforums.com/forum/g...oved-**-33347/

If you don't have an OBD II reader, I will promise it will be worth $50-100 to get one. The link is a list of them that members know work for our cars. Some listed might have only the P Code capability but that will typically give you a lot to go on. They are VERY easy to use and you will get a lot of help here understanding them and advice on what to do: even if you end up with a mechanic, at least you will have a good idea if you are getting reasonable work done to address your issue.