Lock up Mechanism

The lock up mechanism operates in D position (2nd, 3rd, 4th, and 5th), 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 volume 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 volume of the lock up conditions.