2000 XK8 with 11500 on the clock. Have safe mode, asc, etc items with poor power. No code shown on ACTRON CP9185 scanner. Delete all codes and runs fine. After a few miles (30 to 60) fail safe mode comes on again. Replaced T.B. and brake switch hopping to fix. Did not work. Next step is to sell the car and keep the codes for the next car. Any ideas as to what is going on?

Walt

 

I am puzzled if you have no codes how are you clearing them and the car runs better? Is your reader plugged in as you are driving to try and capture the fault? I should mention that Jaguar has a few codes that will not show up on your standard OBDII readers. What is it that you are doing when the car acts up? When you say you replaced the TB where did you get the new one?

 

No codes are shown on the scanner but on the car. Run delete codes and code on car go off and now runs fine.

Walt
2000XK8

 

I assume you mean the check engine light is on, and you clear it temporarily with the code reader. You need to have the codes read by a shop that has Jag software, a dealer if no other choice available.
Then you can come back to the forum with the codes and get help.

 

Other than the TB, the tranny will generate a failsafe mode pretty quick.Your scanner should pick up tranny codes though. Go through th eforum for similar problems and solutions. You mighth have a loose connection or bad harness on the tranny rotary switch.