Diagnostic trouble code (DTC) information CEM-1A56

Condition 

Fig 1: Identifying Driver Information Module

Courtesy of VOLVO CARS OF NORTH AMERICA.

The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) registers that communication with the driver information module (DIM) is not operating.

The diagnostic trouble code (DTC) can be diagnosed when the ignition has been on for more than 10 seconds.

Substitute Value 

• None.

Possible Source 

• No power supply to the driver information module (DIM)
• Open-circuit in the ground lead for the driver information module (DIM)
• Contact resistance in the terminals
• Open-circuit in the wiring for the CAN low speed network to the drive information module (DIM)
• The driver information module (DIM) is not intended for this vehicle (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 controller area network (CAN). See the relevant wiring diagram. 

Fault symptom[s] 

• No gauges working.
• The instrument lighting does not operate.