Diagnostic trouble code (DTC) information

Condition

Fig 1: Identifying Transmission Control Module (TCM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The control modules transmit and receive information via a standardized serial communication method - CAN (Control Area Network). The diagnostic trouble code (DTC) is stored if the transmission control module (TCM) registers serious interference (CAN communication blocked).

NOTE:

In case of a system communication fault, it will not be possible to communicate with the transmission control module (TCM). It will therefore only be possible to read if the fault is intermittent.

Substitute Value

Auxiliary program Emergency mode 1 in the transmission control module (TCM) has started.
HINT: Emergency mode in case of malfunction

Possible Source

Contact resistance or oxidation in the terminals
Open-circuit in the control area network (CAN) wiring.
Short-circuit between the control area network (CAN) wiring.
Internal fault in transmission control module (TCM).
Internal fault in another control module in the same part of the control area network (CAN).

Fault symptom[s]

General warning lamp lit
No gear changing.