Components Description

COMPONENT DESCRIPTIONS

Transmission Unit
The powertrain 4L-80-E transmission unit houses the two solenoid valves which control gear shifts. A pressure control valve is also located on the solenoid valve block. These three valves initiate and control shift patterns within the transmission unit by regulating fluid flow.

Performance Mode Switch
The two position performance mode switch allows selection of "sport" or "normal" mode as required by the driver. The switch input to TCM causes a gear shift pattern change so that gear shifts take place at higher engine revs, enhancing performance, when in "sport" mode. For everyday use, "normal" mode utilizes a shift pattern for optimum driver comfort.

Kick-down Switch
The "kick-down" facility is activated when full downward travel of the accelerator pedal occurs.

Activation of the switch provides a signal to TCM indicating that greater acceleration, and hence downward gear shifts are required. Switch height is adjustable so that kick-down can be achieved at a predetermined throttle opening.

Gear Selection Illumination Module
This module is located above the gear selector mechanism and its sole purpose is to display the selected gear (in red) on receipt of a signal from the decoder module.

Transmission Control Module
The transmission control module (TCM) is an electronic control unit for the control of the Powertrain 4L-80-E automatic transmission. The TCM senses various engine and transmission parameters to provide optimum transmission performance and refinement. The electronic control signals are applied to solenoid valves which operate the hydraulic circuits for gear selection and torque convertor clutch lock-up An electrically operated hydraulic pressure regulator is used to modulate gearshift pressures, giving smooth changes.

The module can operate in three distinct modes; "Normal", "Sport" and "Traction Control". Normal and Sport modes are selected via a manually operated rocker switch, mounted on the rear of the gear selector. Traction control mode is activated by a signal from the Anti-Lock Braking/Traction Control Module (ABS/TC CM), for vehicles fitted with traction control facility.





TRANSMISSION CONTROL MODULE - CONNECTION INFORMATION





ADDITIONAL CONNECTION INFORMATION