The transmission is controlled by an electronic control unit (ECU), which receives signals from various sensors related to the operating modes of the transmission. Based on this data, the ECU can set the optimal vehicle speeds according to the driving style.
Torque from the engine is transmitted to the transmission through a torque converter, which functions as a fluid clutch and acts as an automatic clutch, also providing torque transfer during acceleration.
The gear train provides forward movement in one of the 4 gears or reverse movement. The components of the gear train are controlled by brakes and clutches, which are actuated hydraulically. A pump located in the gearbox provides the necessary hydraulic pressure for the operation of the brake and clutch.
The gearbox is controlled by a selector lever with 7 positions. Position "D" provides automatic gear selection from 4 forward gears. Automatic downshift mechanism changes gear to a lower gear if the accelerator pedal is pressed to the stop. This mode should be used when maximum acceleration of the car is required. Downshifting is similar to other transmission functions and is controlled by the ECU. If the selector lever is in position "3", the car will move only in the first three gears, and in position "2" - only in the first two gears, etc. Setting lower gears is desirable for engine braking, when driving downhill or to prevent unwanted selection of a higher gear on winding roads.
Additionally, three driving programs, controlled by a switch to the left of the selector lever, provide the driver with additional control of the gear according to road conditions. In the "Normal" position, the gearbox operates in the normal automatic mode. In the "Sport" mode, gear changes occur at higher engine speeds. In the "Snow" mode, in the "D" position of the selector lever, the car starts moving in second gear.
Due to the complexity of the automatic transmission, any repairs must be carried out at a Peugeot station.