obd scanner not connecting to ecu

My 2002 XJ VDP was running great and I turned it off to drop off my son. When I went back out to leave, it wouldn't start and I kept getting weird codes; Fail-safe mode, incorrect part fitted (i hadn't done anything to it in months), the rest were ones I've seen when the car is down. Even the Heater/AC unit beeped and showed "ER" on the screen. I had to get it towed home but the transmission was locked in park (I was able to push down the button inside by the gear selector to put it in neutral)

I have tried two different code readers which have worked on my car in the past but now they both say something about not finding or not being able to connect to the car computer.

Any ideas??

Jason Zite
2002 XJ8 VDP

 

I know it sounds like a broken record, but have you tried a hard reset and ensuring the battery was fully charged? Worth a few minutes to give it a go if you haven't yet.

 

Thanks, I have tried that but it didn't work. I've checked all fuses and they are all fine as well.

 

Sounds like a CAN bus fault or the ECM has failed. The INST PK is the GATEWAY to the CAN bus so that could also be a problem.

A COMPLETE scan of ALL the modules might tell you something about the network and connection problems??

You will need a dealer level diagnostic to determine what modules (if any) cannot communicate.

bob