Transmission Control Module (TCM) Description and Operation

Description

The Transmission Control Module (TCM) serves as the brain of the automatic transmission. The module receives and processes signals from various sensors and performs a wide range of control functions to ensure optimal driving conditions for the driver. The TCM is programmed to respond optimally to any driving situation. If a transmission malfunction or failure occurs, the TCM stores the fault information in memory so that the technician can access the DTC and quickly repair the transmission. Functions:

• Monitors vehicle operating conditions to determine the optimal gear.
• Performs gear shifting when the current gear position differs from the determined optimal gear position.
• Determines when to engage the torque converter damper clutch (D/C) and controls its engagement accordingly.
• Calculates the optimal line pressure level by continuously monitoring torque level and adjusting pressure accordingly.
• Diagnoses the automatic transmission (A/T) for malfunctions and failures.