Hey guys, hopefully somebody out there can help direct me. I have a 2005 XJR. the other day i came out into a main road and a car was coming at me at a high rate of speed so i stomped on the pedal and around the second shift it almost felt like it missed a gear or shift and at that point saw a trans fault on the dash. I let off the pedal and the car seemed to shift normal through out my destination and back home. I took it to a trans shop and the codes show P1643 and U2522. The Trans shop says he not sure what it is, weather its electrical or needs trans R&R. He also says the trans shifts fine under low RPM and goes into neutral only when you go into passing gear. like its slipping. Does this sound like electrical or trans rebuild. This Jag has 134k on it. No leaks and all electrical wiring is in tack. I was just saying before this happened how nice the trans felt on this Jag.

 

I have P1643 as a CAN fault (for PCM / TCM comms) - see JTIS.

If it's that then don't rush to rebuild the trans!

 

Yep, the workshop manual gives the following possibilites for P1643:

- CAN open circuit fault, TCM to ECM
- CAN short circuit fault
- TCM failure
- ECM failure

For U2522 it says:

"CAN message timeout from TCM: ie CAN message is not received at specified rate, or is missing"

and further on:

"Data missing for transmission gear selected"

 

Does any body know of a independent Jaguar shop that knows these transmissions ,so i can go to just one shop opposed to hearing not sure and i have to keep going from one shop to another in Los Angeles or Ventura county

 

You look to have an ELECTRICAL problem. Don't even look for a trans shop unless it isn't that.

 

Fully agree with JagV8.

Check your TCM connector and your connectors at the ECM as a starting point.

 

Thanks Guys, I made a call out to a friend of my neighbor that is the foreman at our local Jaguar dealer (very nice man)he's help me with a lot of other issues in the past. He's says theses faults are differently network related and unlikely the trans and will do some more research. He can also test the adaptive values in the trans and determine how much correction the computer is applying for wear. I have my fingers crossed. Might be a little cheaper than a trans over haul@ $5K.