Torque Converter Clutch Solenoid Valve Control

The torque converter clutch solenoid valve is controlled by the TCM. The plunger closes the drain circuit during the "OFF" period, and opens the circuit during the "ON" period. If the percentage of OFF-time increases in one cycle, the pilot pressure drain time is reduced and pilot pressure remains high.

The torque converter clutch piston is designed to slip to adjust the ratio of ON-OFF, thereby reducing lock-up shock.

Fig 1: Identifying Torque Converter Clutch Solenoid Valve Control

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Pilot Pressure Graph

Courtesy of NISSAN MOTOR CO., U.S.A.

OFF-time INCREASING

Amount of drain DECREASING

Pilot pressure HIGH

Lock-up RELEASING

Fig 3: Torque Converter Clutch Control Valve Operation

Courtesy of NISSAN MOTOR CO., U.S.A.