System Operation

WARNING: This page is about a different car, the 2018 Land Rover Discovery Sport. However, it is still accessible from the selected car via links, so may be relevant.

Operation of the transmission is controlled by the TCM, which electrically activates various solenoids to control the transmission gear selection. The sequence of solenoid activation is based on programmed information in the TCM memory and physical transmission operating conditions such as vehicle speed, throttle position, engine load and rotary TCS position.

Engine torque is transferred, via operation of combinations of clutches to the planetary gear trains. The gear trains are controlled by reactionary inputs from brakes and clutches to produce the 9 forward gears and 1 reverse gear.

The shift elements (clutches and brakes) are actuated hydraulically. Fluid pressure is applied to the required clutch and/or brake, pressing the plates together and allowing drive to be transmitted through the plates. The purpose of the shift elements is to perform power-on shifts with no interruption to traction and smooth transition between gear ratios.