U0140

U0140

Front control module, communication

NOTE: Internal function test completed.

Diagnostic conditions
The front control module initially tests internal function sequences after wake-up. If they are OK, all diagnosable outputs are then tested and any faults are stored.

Front control module wake-up through:
- event-induced CAN message
- "Ignition on"

Possible fault causes
- No power supply for front control module
- Front control module is incorrectly coded
- Short circuit or open circuit in the CAN convenience
- Front control module faulty (in most cases the cause is not the front control module but incorrect coding.)

Fault effects
- Communication via the CAN convenience is no longer possible.
- No other control modules are able to communicate with the front control module.

Affected contacts on the front control module connector

Connector A:
- 1 power supply - terminal 30
- 7 CAN convenience low
- 15 CAN convenience high
- 21 power supply - terminal 15
- 35 power supply - terminal 15 (redundant)

Connector B:
- 20 power supply - terminal 15 (redundant)
- 40 ground supply - terminal 31