Diagnostic Trouble Code (DTC) Information TCM-0A31

Condition 

Fig 1: Identifying Engine Control Module (ECM)

Courtesy of VOLVO CARS CORPORATION

The engine control module (ECM) puts a signal about the present torque on the control area network (CAN). The transmission control module (TCM) uses the signal to determine shift points and to adjust system pressure in the transmission.

The diagnostic trouble code (DTC) is stored if the control module detects that:

• There is no torque signal from the engine control module (ECM) or the signal is faulty.

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

Substitute Value 

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

  HINT:  EMERGENCY MODE IN THE EVENT OF A FAULT 

• Neutral control function is blocked.
• Lock-up function is blocked.

Possible Source 

• Fault-trace the 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
• Rough gear shift
• No gear shift
• No lock-up