My 2006 XJ van den plas is in ICU. It started with parking break locking up repeatedly and stopped unlocking with reset. Then suddenly car started misfiring and transmission slipping badly with red check engine light and warning for transmission failure. The transmission guy claims that he changed the valve body but the car is misfiring badly. My mechanic cannot get the codes at all. He said that the plugs were 'foul' and replaced them. The car behaved for a few minutes but started misfiring with transmission problems as before. He does not know what to do as he cannot communicate with the car to know what is wrong.
Should I just cut my losses and send the car to the wreckers ? Jag dealer service guys are not interested in even looking at the car.
Any clues will be much appreciated.
Regards
PeeAm

 

If the valve body was replaced then the mechanic should know if any metal shavings were found in the pan.

If none were found then transmission maybe ok.

Speed wheel sensor issues can cause transmission issues because of incompatible readings between components.

 

Find someone with a Jag capable code reader and see what's up. Assuming you get misfire codes then I would replace the COILS. For some reason weak coil induced misfires on these cars will cause the transmission to misbehave.

Good Luck
Jeff

 

+1 on the above.

 

Thanks Jeff. One coil and all plugs were replaced. I guess we can replace the rest and see what happens.

 

What is the age and condition of the battery? What is the voltage across the terminals, with the ignition in the OFF position, when measured with a voltmeter?

The control modules communicate with each other, so an engine misfire causes the TCM to place the gearbox in limp mode, and displays 'Transmission Fault' on the instrument cluster.

What DTCs are stored in the system? Post them here.