Volvo TAD650VE Workshop Manual page 144

Diagnostic Trouble Codes
142
Fault tracing
FMI 9
Conditions for fault code:
No communication with the engine control unit.
Possible reason:
•
An open circuit in CAN H or CAN L or both CAN
links between EMS 2 and DCU/CIU.
•
An open circuit in Power supply 0V cable between
EMS 2 and DCU/CIU.
•
An open circuit in Power supply input cable be-
tween EMS 2 and DCU/CIU.
•
CAN H short circuited to power supply in pin 4.
Suitable action:
1. Check contact pressure in socket 51 and 55 in
engine connector B.
2. Check for an open circuit or short circuit between
cables in the cable harness between the DCU/CIU
and EMS 2, via the engine connector.
Group 30: Electrical system