Diagnostic Trouble Code (DTC) Information CEM-1A61

Condition 

Fig 1: Identifying Transmission Control Module

Courtesy of VOLVO CARS CORPORATION

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

Substitute Value 

A substitute gear is engaged.

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 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. 

Fault symptom[s] 

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