Started up my xj8 today. I had parked it because the CEL come on. It had gone into restricted performance.
Checked the codes here is what I had P1642 and P1000. I know the P1000 code. Also I got the following too,
CEL, ASC Not Avail, Gearbox Fault, Failsafe Engine Mode, Trac Not Avail and then noticed no tach or temp gage working.
Now I know we have had a lot of rain, so I was wondering if that could have caused it. Never noticed any leaks or water
issues before. Any help or direction will be appreciated.

 

1642 reads as"CAN circuit malfunction", possible causes are "CAN short circuit fault Control module failure – check for additional flagged DTC(s) to locate control module source"

I don't have the right direction to point you in but some forum searches will likely send you in the right path after a few dead end rabbit holes. Since the car was stored, maybe you had a flat or low battery? Might be a low voltage situation, which even though I haven't experienced it, I understand can play hell with the x308. Worth unhooking and toss the battery on a charger overnight and let it do a full charge cycle.

 

Let me now add it will not shift out of park....
What's next???

 

Do you have brake lights? Shift interlock is on the same circuit as the brake lights.

You can get it out of park by removing the torx screw from the top of the shifter and then press the torx driver into the hole to release the shift lock.

 

Yes I have brake lights. Now I did go out and start it, the tach, temp gauge worked.
I was able to shift into drive, moved the car back and forth. Then the tach, temp gauge stopped working.
Then I couldn't shift out of park again. PLUS I have a new code now. P1797.. Guess I'm trying to get the
award for most codes or something... Guess I will have to start over tomorrow and see what I can do.
As always any help for this novice, greatly appreciated.

 

Low battery voltage maybe.

 

First thing to check is the battery voltage with the car running as a lower voltage can cause all kinds of crazy codes.
Secondly I would check the tightness and cleanliness of all the connections at the EMC and TCM. The main ECM
connector is at the right hand, rear corner of the engine bay, held in place with a security torx screw. I would bet
Rancho Cucamonga has grown considerably from the last time I was there in the mid 90's.