Transmission Electronic System: TCM

The TCM for the transmission is mounted on top of the main control valve body. The control module for the transmission has been designed to operate correctly in the environment in which the TCM is located.

The transmission control module is activated and deactivated by the ignition supply and is connected to the transmission link harness by a 16-way connector.

The TCM controls the operation of the transmission. The TCM processes information received in both analogue and digital form such as:

• Transmission input speed.
• Output speed.
• Throttle pedal position.
• Gear selector position.
• Engine torque.
• Engine speed.
• Transmission fluid temperature.
• Brake pedal status.
• Engine oil temperature.
• Coolant temperature.
• ABS wheel speed.

This information is then used by the TCM to decide which shift pattern to select and for shift energy management. Electro-hydraulic solenoid valves and pressure regulators control the transmission gear changes.

Five pressure regulators and one solenoid valve are used to control direct transmission fluid flow to select internal clutches and control the fluid pressure at the clutch. A separate pressure regulator is used exclusively for torque converter clutch control.

The TCM monitors all TCM inputs and outputs to confirm correct system operation. If a fault occurs the TCM is able to perform default action and inform the driver of the problem, this is by the instrument cluster message center.