I've got a 2000 XJ8 that does not start nor crank. The instrument pack does not light up, the a/c does not turn on nor do the shifter positions light up. IDS will not talk to the car at this point giving <ERR> for every module. After awhile it will start normally like nothing was wrong, then again later go back to non start mode. Any others ever experience this behavior from an XJ8? Also the message center shows every possible warning (trac, abs, gearbox fault, engine fault, electrial fault, low brake fluid, et al)
Thx

 

All the symptoms of an electrical problem. Check battery voltage under load as in lights on. Most likely a failed battery or battery connection.

Check B+ and ground cable connections both in the trunk and under hood. Swap the ECM power relay with another. Most are the same. It is the stand-alone relay in the center of the right relay/fuse housing.

 

Sounds like the CAN failure.

Old TSB Service Action S484 describes this fault.

Here is the old TSB

bob gauff