Operation

This system, electrically controls the line pressure, throttle pressure, lock-up pressure and accumulator pressure etc. through the solenoid valve. The electronically controlled transmission is a system which precisely controls gear shift timing and lock-up timing in response to the vehicle's driving conditions and the engine operating conditions detected by various sensors, making smooth driving possible by shift selection for each gear which is the most appropriate to the driving conditions at that time, and controls the engine torque during shifting to achieve optimum shift feeling.

1. GEAR SHIFT OPERATION
During driving, the engine warm up condition is input as a signal to TERMINAL (B) 14 of the engine control module from the engine coolant temp. sensor and the vehicle speed signal from the vehicle speed sensor No. 2 is input to TERMINAL (C) 5 of the engine control module. At the same time, the throttle valve opening signal from the throttle position sensor is input to TERMINAL (B) 13 of the engine control module as a throttle angle signal.
Based on these signals, the engine control module selects the best shift position for driving conditions and sends current to the electronically controlled transmission solenoids.
When shifting to the 1st speed, the current flows from TERMINAL (C) 1 of the engine control module to TERMINAL 6 of the electronically controlled transmission solenoid to GROUND, and continuity to No. 1 solenoid causes the shift (No. 2 solenoid does not have continuity at this time).
For the 2nd speed, the current flows simultaneously from TERMINAL (C) 2 of the engine control module to TERMINAL 12 of the electronically controlled transmission solenoid to GROUND, and from TERMINAL (C) 1 of the engine control module to TERMINAL 6 of the electronically controlled transmission solenoid to GROUND, and continuity to No. 1 and No. 2 solenoids causes the shift.
For the 3rd speed, there is no continuity to No. 1 solenoid, only to No. 2 solenoid, causing the shift.
Shifting into the 4th speed (Overdrive) occurs when no current flows to No. 1 and No. 2 solenoids. The No. 4 solenoid (for accumulator back pressure modulation) is installed to adjust the back pressure on the accumulator and control the hydraulic pressure during shifting and lock-up in order to provide smooth shifting with little shift shock.

2. LOCK-UP OPERATION
When the engine control module decides, based on each signal, that the lock-up condition has been met, the current flows from TERMINAL (C) 13 of the engine control module to TERMINAL 10 of the electronically controlled transmission solenoid to TERMINAL 4 to TERMINAL (C) 7 of the engine control module to GROUND, so continuity to No. 3 solenoid (Lock-up) causes lock-up.

3. STOP LIGHT SW CIRCUIT
If the brake pedal is depressed (Stop light SW ON) when driving in lock-up condition, a signal is input to TERMINAL (D) 6 of the engine control module. The engine control module operates and cuts the current to the solenoid to release lock-up.