Diagnostic Trouble Code Information

Condition 

Fig 1: Identifying Glow Plug

Courtesy of VOLVO CARS CORPORATION

If the glow plug circuit is short-circuited to voltage supply, ground or if there is an open circuit, the control unit will interpret this as a fault, and diagnostic trouble code CEM-5F46 will be set.

Substitute Value 

• None.

Possible Source 

• Damaged glow plug.
• Contact resistance in control unit connector.
• Contact resistance in the glow plug's electrical connection.
• Open circuit in signal wire.
• Signal wire short-circuited to ground or voltage supply.

Fault symptom[s] 

• Poor interior heating.