I have a 97 XK8 that does not want to shift between 2nd and 3rd. The car revs up and goes into limp mode. All other shifts up and down are normal. If I use the left side of the shifter and let off of the gas it will shift into third. I have 1730 and 1734 fault codes. Could it be my TCM thats causing my problems. I changed the valve body along with trans filter and fluid. The transmission is a replacement from a rolled over 1997. Should I have replaced the computer with the one from the rolled overcar? I have been looking for a used TCM to try to see if that is causing this problem. My computer has LJA 2401 AB on the data tag Is this what I need to match up with the replacement computer? Is there any where I can get my computer checked? Thanks for your time. John

 

The Jaguar DTC Summary for the 1997 MY 5HP Transmission gives the following for P1730 and P1734:



The 'Possible Causes' cross references P0721:



The causes range from the simplest being low fluid, through the two speed sensors to harness issues between the transmission and the TCM.

If the replacement transmission operated correctly after the swap and the fault developed later, then fault is likely to be one of the above. If the fault has been present ever since the swap then the TCM could be the cause or the replacement transmission could have already had a fault.

Graham

 

It would certainly benefit from having the previous transmission's adaptations cleared and you starting fresh. Dealer can do this for probably 1 hr diagnostic time, while they're at it, have the fluid rechecked, just for peace of mind.