Diagnostic trouble code (DTC) information CEM-1A58

Condition 

Fig 1: Identifying Radio And Car Phone

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble codes (DTCs) are stored if the central electronic module (CEM) registers that communication with the phone module (PHM) is not operating.

Substitute Value 

None.

Possible Source 

• No power supply to the phone module (PHM)
• Open-circuit in the ground lead to the phone module (PHM)
• Contact resistance in the terminals
• Open-circuit in the wiring for the CAN low speed network to the phone module (PHM)
• The phone module (PHM) is not intended for this car (for example a used control module with different software/hardware).

HINT: If several diagnostic trouble codes (DTCs) are stored in the central electronic module (CEM) for communication faults with other control modules in the low speed network, this indicates a common fault in the Control area network, see the wiring diagram. 

Fault symptom[s] 

• The carphone does not function
• The menu system does not operate.