Diagnostic Trouble Code (DTC) Information CEM-1A66

Condition 

Fig 1: Identifying Infotainment Control Module

Courtesy of VOLVO CARS CORPORATION

The central electronic module (CEM) checks the communication with the infotainment control module (ICM).

Diagnostic trouble codes (DTCs) are stored if the central electronic module (CEM) registers a fault in the communication with the infotainment control module (ICM).

The diagnostic trouble code (DTC) can be detected when the ignition is on for at least 10 seconds and the battery voltage is above > 10.5 volts.

Substitute Value 

• None.

Possible Source 

• No power supply to the infotainment control module (ICM)
• Open-circuit in the ground lead to the infotainment control module (ICM)
• Contact resistance in the terminals
• Open-circuit in the wiring for the CAN low speed network to the infotainment control module (ICM)
• The infotainment control module (ICM) 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. 

Fault symptom[s] 

• The audio system display does not function.