Key to hydraulic flow diagram

Lock – up Control Solenoid Valve A: ON. Lock – up Control Solenoid Valve B: ON When the vehicle speed further increases, the throttle B pressure is increased in accordance with the throttle opening. The lock – up timing valve overcomes the spring force and moves to the left side. Also, this valve closes the oil port leading to the torque converter check valve.

Under this condition, the throttle B pressure working on the right end of the lock – up control valve becomes greater than that on the left end (modulator pressure in the left end has already been released by the solenoid valve B); i.e., the lock – up control valve is moved to the left. The torque converter back pressure is then released fully, causing the lock – up clutch to be applied.

Key to hydraulic flow diagram

Note: The components shown in this illustration have the same reference letters as those on the preceding pages.

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
13. WW Throttle B pressure
14. XX Modulator pressure
15. YY Line pressure