System Outline

Previous automatic transaxle have selected each gear shift using mechanically controlled throttle hydraulic pressure, governor hydraulic pressure and lock­up hydraulic pressure. The ECT, however, electrically controls the line pressure, throttle pressure, lock­up pressure and accumulator pressure etc. through the solenoid valve. The ECT is a system which precisely controls gear shift timing and lock­up timing in response to the vehicle’s driving conditions and the engine condition detected by various sensors. It makes smooth driving possible by shift selection for each gear which is the most appropriate to the driving conditions at that time, and by preventing downing, squat and gear shift shock when starting off.

1.Gear Shift Operation

During driving the engine warm up condition signal is input from water temp. sensor to TERMINAL THW of the engine ECU, and the vehicle speed signal is input from the speed sensor to skid control ECU with actuator, and are sent to the engine ECU through communication control. At the same time, the throttle valve opening signal is sent from the throttle position sensor to the TERMINALS VTA1 and VTA2 of the engine ECU, as the throttle angle signal.

2.Lock­Up Operation

When the engine ECU decides based on each signal that the lock­up condition has been met, the current flows through TERMINAL DSL of the engine ECU to TERMINAL 3 of the ECT solenoid to GROUND.

3.Stop Lamp SW Circuit

If the brake pedal is depressed (Stop lamp SW on) when driving in lock­up condition, a signal is input to TERMINAL STP of the engine ECU. The engine ECU operates and cuts the current to the solenoid to release lock­up.