Lock-Up System: Notes

The lock-up mechanism of the torque converter clutch operates in D position/mode, S position/mode, and L position/mode* at transmission fluid temperature exceeding 68 deg.F (20 deg.C). 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 transmission fluid pump. As this takes place, the input shaft and the drive pulley shaft rotate as the same as the engine crankshaft. Together with hydraulic control, the TCM optimizes the timing of the lock-up mechanism. When shift solenoid valve B is turned ON by the TCM, shift solenoid valve B pressure switches lock-up ON and OFF. The CVT lock-up clutch control solenoid valve controls the volume of lock-up.