Diagnostic trouble code (DTC) information

Condition 

Fig 1: Identifying Transmission Control Module (TCM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The engine control module (ECM) puts the signal for the engine speed on the CAN network. The transmission control module (TCM) uses the signal to check the lock-up function.

If the transmission control module (TCM) registers that the speed signal from the engine control module (ECM) is missing or is indicated as incorrect, the diagnostic trouble code (DTC) is generated.

The diagnostic trouble code (DTC) can be diagnosed when the ignition is turned on and the CAN network is OK.

Substitute Value 

• Auxiliary program Emergency mode 1  in the transmission control module (TCM) has started.

  HINT:  Emergency mode in case of malfunction 

Possible Source 

• Seek cause of fault in central electronic module (CEM).
• Locate the cause of the fault in the engine control module (ECM).
• Intermittent open circuit or short-circuit on the CAN lead between the engine control module (ECM) and the transmission control module (TCM).

Fault symptom[s] 

• General warning lamp lit
• Harsh gear changing
• No gear changing.
• No lock-up function.