Key to hydraulic flow diagram

In D4 position in 2nd, 3rd and 4th, and D3 position in 3rd, pressurised fluid is drained from the back of the torque converter through an oil passage, causing the lock-up piston to be held against the torque converter cover. As this takes place, the mainshaft rotates at the same speed as the engine crankshaft. Together with hydraulic control, the transmission control module optimizes the timing of the lock-up system. Under certain conditions, the lock-up clutch is applied during deceleration, in 3rd and 4th speed.

The lock-up system controls the range of lock-up according to lock-up control solenoid valves A and B, and throttle valve B. When lock-up control solenoid valves A and B activate, modulator pressure changes. Lock-up control solenoid valves A and B are mounted on the torque converter housing, and are controlled by the transmission control module.

Key to hydraulic flow diagram

1. P Lock-up control solenoid valve A
2. Q Lock-up control solenoid valve B
3. V Lock-up shift valve
4. W Lock-up control valve
5. Z Torque converter
6. DD Lock-up timing valve
7. EE Torque converter check valve
8. FF Regulator valve
9. II Oil cooler relief valve
10. JJ Relief valve
11. KK Oil pump
12. MM Oil cooler