System Outline

Previous automatic transaxles have selected each gear shift using mechanically controlled throttle hydraulic pressure, governor hydraulic pressure and lock up hydraulic pressure. The electronically controlled transmission, however, electrically controls the line pressure, throttle pressure, lock up pressure and accumulator pressure etc. through solenoid valves. The electronically controlled transmission is a system which precisely controls gear shift timing and lock up timing in response to the driving conditions and the engine condition detected by various sensors. It makes smooth driving possible by precisely selecting the gear which is the most appropriate to the driving conditions at that time, and by preventing downing, squatting, and gear shift shock when starting off.

1. Gear Shift Operation 

   During driving the engine warm up condition signal is sent from the E.F.I. engine coolant temperature sensor to TERMINAL THW of the ECM, and the vehicle speed signals are sent from the speed sensors to the brake actuator assembly, and are then sent to the ECM through communication control. At the same time, the throttle valve opening signal is sent from the throttle with motor body assembly to the TERMINALS VTA1 and VTA2 of the ECM, as the throttle angle signal.

2. Stop Light Switch Assembly Circuit 

   If the brake pedal is depressed (Stop light switch assembly is ON) when driving in the lock up condition, a signal is sent to TERMINAL STP of the ECM. The ECM operates and cuts the current to the solenoid to release lock-up.