Diagnostic trouble code (DTC) information CEM-1A64

Condition 

Fig 1: Identifying Active On Demand Coupling

Courtesy of VOLVO CARS OF NORTH AMERICA.

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

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 differential electronic module (DEM)
• Open-circuit in the ground lead to the differential electronic module (DEM)
• Contact resistance in the terminals
• Open-circuit in the wiring for the CAN high speed network to the differential electronic module (DEM)
• The differential electronic module (DEM) 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 high speed network, this indicates a common fault in the Control area network, see the wiring diagram. 

Fault symptom[s] 

• Four wheel drive is not functioning
• Message in the display (not S60 model year 2002)
• The anti-spin warning lamp is lit (up to and including 2002 model year)
• General yellow warning lamp lit (from model year 2003 inclusive).