Description And Operation: Description

Transmission Control Module (TCM) is the automatic transmission's brain. The module receives and processes signals from various sensors and implements a wide range of transmission controls to ensure optimal driving conditions for the driver. TCM is programmed for optimal response to any on-road situation. In the event of a transmission failure or malfunction, TCM stores the fault information in memory so that the technician may reference the code and quickly repair the transmission.

Fig 1: Identifying Transmission Control Module

Courtesy of KIA MOTORS AMERICA, INC.

Component location:  Mounted with the ECM on the top right side of the engine compartment.

Functions 

• Determines the optimal gear based on the vehicle's driving conditions.
• The system shifts gears if it determines that the optimal gear differs from the current gear.
• Determines whether to use the damper clutch (D/C). Controls the D/C when necessary.
• Determines the current torque to compute and supply the optimal line pressure.
• Diagnoses problems in the automatic transmission (AT).