Transmission control units are hydraulic or electrohydraulic components for the operation of automatic transmissions in passenger cars and trucks. Electrohydraulic transmission controls consist of hydraulic and electronic control components. The electronics determine the optimum time for a shifting operation, while the clutch and shifting operations are actuated via solenoid valves and hydraulic actuation of the actuators in the transmission. The electronic transmission control system takes into account numerous sensor data, including engine speed, engine load, speed, driving program and transmission oil or coolant temperature, when determining the correct switching time. In addition to critical system conditions, for example at excessively high operating temperatures, season characteristics, slopes or gradients. As a side effect, safety and driving comfort are increased while fuel consumption and pollutant emissions are reduced. Optionally, electrohydraulic transmission controls offer the driver particularly economical or sporty driving stages.
