Fault Symptom

Fault symptom
Ventilation fan and electric rear window cannot start until 20 seconds after the engine has been started.

Diagnostic help
Ignition +54 can be checked in DICE using the diagnostics tool.
If +54 is missing when +15 is present, bus message Ignition +54 ON after 20 seconds. ACC uses bus message Ignition +54 in order to cut out the ventilation fan when the engine is started.