+54 Missing

Ventilation fan cannot be started until 20 seconds after Ignition has been switched to position ON.

+54 Missing:

Fault Symptoms
Electric rear window and ventilation fan cannot start until 20 seconds after the ignition has been turned to the ON position (+54 voltage).

Diagnostic Help
Ignition +54 can be read in DICE using the diagnostic tool.

If +54 is missing when +15 is present, the bus message Ignition +54 ON is generated after 20 s.

The ACC uses the bus message Ignition +54 to disconnect the ventilation fan when the engine is being started.