Diagnostic Trouble Code (DTC) Information TCM-P179900

Condition 

Fig 1: Identifying Transmission Control Module (TCM)

Courtesy of VOLVO CARS CORPORATION

The brake control module (BCM) puts a signal for the vehicle speed on the CAN network. The transmission control module (TCM) uses the signal to diagnose the gearbox input and output speed sensors.

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

Substitute Value 

• Nothing.

Possible Source 

• Internal fault in brake control module (BCM).
• Fault on CAN network.

Fault symptom[s] 

• General warning lamp lit