I have a 1990 xjs baseline and when I start it, the transmission light comes on and its in limp mode. I discovered if I turn the key one click back, push the gear selector up and to the right,then restart, the light goes out and all is well. I will admit that there are plenty of cigarette ashes down there and I intend to suck theme out, but has anyone else had this? I'm weary of double starting. Thanks in advance. Jeffrey

Submitted by steve.veris@sb… on Sat, 07/17/2010 - 14:01

Since I can't find anyone to diagnose/repair this problem, can limp mode be easily disabled? At least the transmission wouldn't be slamming into reverse when backing up, and stuck in 3rd gear when driving. My theory is to limit the wear and tear and/or damage to the trans, then continue trying to find the root cause.

Submitted by steve.veris@sb… on Sat, 07/10/2010 - 15:58

William - thanks for the tip. But, I've been to my regular mechanic of some 30 years now and he said he could not diagnose which faulty component was causing the problem. If it's as easy to diagnose as you say, I would think plenty of shops here would be willing to take my money. I do know that both a faulty O2 sensor and/or a bad TPS sensor can activate limp mode - along with other causes. But I cannot afford to throw parts at the problem. And why would my Jaguar dealer and master mechanic friend turn me away? When you say "trace the wires" do you mean the leads to the O2 sensor? If the leads are both connected, how do I tell if the sensor id bad? TIA.

Submitted by bonnettoboot@e… on Fri, 07/09/2010 - 21:20

Hello Steve, you need to go to a mechanic, ANY mechanic who has common sense and an alldata subscription . This fault could be related to a disconnected oxygen sensor, vurtually any engine/brake fault will activate the limp home mode via the transmission! You may be able to trace the wires yourself at the back of the engine compartment on each side.

Submitted by steve.veris@sb… on Sun, 07/04/2010 - 13:19

I have a similar stuck in limp mode problem, and the error codes I get seem to indicate a bad TPS as the culprit. I also have trouble accelerating if I give the car anything but a gradual increase in throttle. Any tips on how to calibrate the TPS? My Jaguar dealer and Master Mechanic - who is a personal freind - say that they no longer have the required equipment. Also, can the later model one be substituted? I can't find the PN but I think the earlier one I have is a DB2889 and the later one is a DB2226. Goog;e search is not cooperating right now. TIA.