Transmission Control Module (TCM)

Fig 1: Identifying Transmission Control Module, Engine Control Module (ECM), Mass Air Flow (MAF) Sensor And Throttle Position (TP) Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The transmission control module (1) receives the following information from the engine control module (ECM) (2): 

• engine air mass and speed from the mass air flow (MAF) sensor (3)
• throttle angle from the throttle position (TP) sensor (4).

The transmission control module (TCM) uses this information to calculate gear shifting.