Fault code P1796, Jaguar XKR 1999

On a long journey, a red warning light suddenly came on and the text “Restricted performance” appeared. I stopped, restarted the engine and everything was fine. Later, the same thing happened, and the warning comes sooner, now after a couple of minutes. The car runs as it should, but the speed is limited to 140 km / h , 85 miles/h.

A Jaguar workshop read the fault codes, and these were:

ABS C1095, U2012

Climate control B1861, U1263

Instrument U1250, U1261, B1238

Engine P1796

The workshop said that it is a connector fault in the cable harness that gives all these fault codes. They are willing to take the car in and search but can of course not give a cost estimate. They charge £ 200 / hour. Unknown number of hours plus repair cost…

Has anyone come across something similar and can suggest where to start looking?

What is the battery status?

I changed to a new battery but it didn’t help.

Do you have a code reader and are consistently pulling the P1796 code after each failure/reset cycle? It might be worth checking the harnesses and plugs leading into the transmission. I seem to recall P1796 is associated with ECU/transmission communication.

I would not be too worried about the other codes unless they recur. Often I find in a car that has not had codes read for a long time, a variety of the more oddball codes are piled up in memory. But once cleared, they don’t return.


Info for you.

W5A580_1998.pdf (35.3 KB)
W5A-580_TRANS_OBDII.pdf (179.5 KB)

Thanks a lot! Very useful!