Going to the gym today the car (03 xjr) had the abs/trac light come on, engine completely died, coasted into a parking lot, pedal wouldn't respond when restarted. Also no response on the throttle body cable side Idled okay but a bit rough. Called my wife to come pick me up and then figured I'd try a battery disconnect reset. Started right up and ran fine. No issues since (put maybe 15 miles on it. Plugged in and pulled the codes. Only codes there are a couple codes related to the rear door sensors in the history so I don't think it deleted the codes. I'm guessing throttle position sensor is going bad? I know I've read about it on the xk8 being rebuildable, is the XJR similar and rebuildable. If so any recommendations on where to send it or can I do it myself? Of course we're going away this and next weekend and that is the car we are planning on using.

 

Hi! I have an XJ 308 and I've had an intermittent fault with strange codes and engine going into fail safe mode. I've changed the battery earth lead, the engine earth lead and the inertia switch. so far so good. The battery earth lead is prone to failure and it a cheap fix to try.

 

Thanks Gaine. Took it for a weekend trip of maybe 350 or so miles. Performed fine save for a traction control then engine fault again. Tried to pull codes again and nothing there. Fault was gone on restart then ran fine from then on. I do have a reman throttle body coming but was hoping to get a code or the like before going to the trouble of putting it in. Need the car for a 600 mile trip next weekend. On a side note I did replace the battery in the early spring and at that time cleaned up the chassis ground from the battery in the rear. Will check both again. The lack of codes has got me stumped.

 

Is your code reader able to read C codes for the abs system? Does the traction control message say failure or fault? If not, it may be just a message that the system was performing correctly in response to exuberance in your driving style.

 

Just thinking about the 03 XJR. Does this have the Mercedes transmission or the 6 speed ZF? The Mercedes unit can result in a engine fault and failsafe if a speed sensor is failing.

 

Yes, code reader is an autoenginuity so yes it should pick up all the Jag specific codes. The lack of stored codes is what gets me.