CAN timeout of MBS master (MBSM)
If other ECUs communicationg on the same CAN bus have recorded CAN bus failures then it is not likely that it is a problem with this particular DCU. Instead look for faults in the cable harness or MBSM power supply. Check CAN bus wires, connectors and terminals for mechanical damage. Measure the CAN bus wiring for short circuit or broken wires. Be aware that it could be an intermittent fault that appears due to vibrations or other circumstances.
What you'll see
The DCU is not following commands from MBS. The workshop button at the door still works normally.
System reaction
The DCU will finish any ongoing operation (like opening or closing) and then stop and wait for CAN communication to start. It will keep following workshop button comands.
Diagnostic depth
Communication with the MBSM has timed out (communication interrupted)
- Faulty MBSM or DCU - Faulty brown CAN bus - MBSM or DCU disconnected from the brown CAN bus, for example due to: -- broken CAN wiring -- the CAN bus wires have been disconnected while the DCU or MBSM was powered up during maintenance work or similar. - Power supply failure of MBSM while the DCU was powered up and in operation.