System Outline

This system electronically controls the gear shift timing, lock-up timing, the clutch and brake hydraulic pressure, and the engine torque during shifting to achieve optimum shift feeling, according to the vehicle driving conditions and engine operating conditions as detected by various sensors.

1. GEAR SHIFT OPERATION
During driving, the Engine Control Module selects the shift point for each gear which is most appropriate to the driving conditions, based on input signals from the engine coolant temp. (ECT) Sensor (EFI Water Temp. Sensor) to TERMINAL THW of the ECM , and also the input signals to TERMINAL SPD of the ECM from the vehicle speed sensor devoted to the electronically controlled transmission. Current is then output to the Shift Solenoids.
When Shifting to 1st speed, current flows from TERMINAL S1 of the ECM to TERMINAL 3 of the ECT Solenoids connector --> Ground, and continuous to the No.1 solenoid, which causes the shift.
For 2nd speed, current flows from TERMINAL S1 of the ECM to TERMINAL 3 of the ECT Solenoids connector, and from TERMINAL S2 of the ECM to TERMINAL 1 of the ECT Solenoids connector, --> Ground and continuous to Solenoids No.1 and No.2, causing the shift.
For 3rd speed, there is no continuous to No.1 Solenoid, only to No.2, causing the shift.
Shifting into 4th speed (Overdrive) takes place when there is no continuous to either No.1 or No.2 solenoid.

2. LOCK-UP OPERATION
When the ECM judges from each signal that Lock-Up operation conditions have been met, current flows from TERMINAL SL of the ECM to TERMINAL 1 (for 5S-FE), (or 2, for 7A-FE), of the ECT Solenoids connector --> Ground, causing continuous to the Lock-Up solenoid which causes lock-up operation.

3. STOP LIGHT SWITCH CIRCUIT
If the brake pedal is depressed (Stop Light SW ON) when driving in lock-up condition, a signal is input to TERMINAL B/K of the ECM, and continuous to the lock-up solenoid is cut, preventing lock-up operation.

4. OVERDRIVE CIRCUIT
^ O/D Main SW ON
When the O/D main SW is turned ON (SW Point Is Open), a signal is input to TERMINAL 0D2 of the ECM, and ECM operation causes gear shift when the conditions for overdrive are met.

^ O/D MAIN SW OFF
When the O/D Main SW is turned OFF (SW Point Is Closed), current through the "O/D OFF" indicator light flows through the O/D Main SW to Ground, causing the indicator light to light up. At the same time, a signal is input to TERMINAL OD2 of the ECM, which prevents shift into overdrive.