Thread: P38 diagnostic tool

Thanks Keithy. I only had the ignition on so I'll have another try later and see if I am successful.

The P38 vehicle systems have a couple of odd quirks.

The first is that you cannot communicate with the BeCM if the vehicle is alarmed or the engine is running.

The second is that the ABS cannot be communicated with when the vehicle is moving or has moved above about 7 KPH.

The ABS also has a nasty aspect in that once communicated with diagnostically, it keeps control of the diagnostic bus and thus prevents communication to the other ECU's using the same bus, which is everything except the Airbag and EAS. You will therefore need to re cycle the ignition switch if you want to communicate with any other ECU after accessing anything on the ABS.

I hope this helps

ATB

Colin