Combustion air fan motor
â–¶ How to fix
Check the combustion air fan motor. See Internal wiring diagram under Connections. Measurement points 1 and 2 in connector A for the control unit. Resistance: Approximately 4 ohms. If necessary, renew the control unit.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
Auxiliary heater fails to start.
Possible cause
Open circuit in the combustion air fan motor circuit.