Diagnostic trouble code (DTC) information CEM-1A61

Condition

Fig 1: Identifying Transmission Control Module (TCM)

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 transmission control module (TCM) is not operating.

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

NOTE: If CEM-1A6X diagnostic trouble codes (DTCs) are stored, the central electronic module (CEM) must not be replaced as the diagnostic trouble code (DTC) indicates a communication fault in the Control area network

Substitute Value

None.

Possible Source

No power supply to the transmission control module (TCM)
Open-circuit in the ground lead to the transmission control module (TCM)
Contact resistance in the terminals
Open-circuit in the wiring for the CAN high speed network to the transmission control module (TCM)
The transmission control module (TCM) 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 high speed network, this indicates a common fault in the Control area network, see the wiring diagram.

Fault symptom[s]

No shifting.
Malfunction indicator lamp (MIL) lit
Message in the display.