Diagnostic trouble code information

Condition 

Fig 1: Identifying Combustion Fan Circuit

Courtesy of VOLVO CARS OF NORTH AMERICA.

If the control unit receives a signal indicating that the heater fan is operating to slowly, it will interpret this as a fault, and trouble code CEM-5F3E will be set.

Substitute Value 

• None.

Possible Source 

• Defective heater fan.
• Contact resistance in control unit or heater fan connector.

Fault symptom[s] 

• Poor interior heating.