Diagnostic trouble code information

Condition 

If the control unit loses contact with the HEM control unit when the heater is in operation, diagnostic trouble code CEM-5F4D will be stored.

Substitute Value 

• None.

Possible Source 

• Contact resistance in the terminals.
• Open-circuit in the communication cable.
• Short-circuit to ground in the communication cable.
• Short-circuit to supply voltage in the communication cable.

Fault symptom[s] 

• Poor interior heating.