Diagnostic trouble code information

Condition 

Fig 1: Identifying Combustion Fan Circuit

Courtesy of VOLVO CARS OF NORTH AMERICA.

If the heater fan circuit is short-circuited to voltage supply, the control unit will interpret this as a fault and the diagnostic trouble code CEM-5F3C will be set.

Substitute Value 

• None.

Possible Source 

• Signal wire short-circuited to voltage supply.
• Defective heater fan.

Fault symptom[s] 

• Poor interior heating.