Lock up System: Notes

The lock up mechanism of the torque converter clutch operates in D position (2nd, 3rd, 4th, and 5th), and in D3 position (2nd and 3rd), and M (sequential sport shift mode) position (3rd, 4th, and 5th). The pressurized fluid is drained from the back of the torque converter through a fluid passage, causing the torque converter clutch 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 the hydraulic control, the PCM optimizes the timing and amount of the lock up mechanism. When the shift solenoid valve E is turned on by the PCM, shift solenoid valve E pressure switches the lock up shift valve lock up on and off. The A/T clutch pressure control solenoid valve A and the lock up control valve control the amount of the lock up.