[philrocks]

Just for completeness sake:

I put in 3 different fault readers, standard OBD one, cheap OBD bluetooth - mobile app one, and Lightfoot device prototype (My companies one, only reads MIL codes). They picked up no faults at all.

Took it to a garage, which picked up:
Immboiliser (CEM) - 3A00 - Engine control Unit, signal to high, permanant.
Multifunction (CEM 1) - 3A00 same as previous.
Engine (B5354T3 2.5L ME9) - 740C - CAN: communication CEM, signal to high, permanant

The garage used some swedish kit (not VIDA DICE), and the above dont really help me get any closer. Just storing it here for reference.