Torque Converter Clutch (TCC) Line Pressure Control (LPC)

Courtesy of FORD MOTOR COMPANY

The TCC solenoid is a normally low variable force solenoid. The TCC solenoid uses proportional operation. As the current from the TCM decreases, the pressure from the solenoid decreases. As the current from the TCM increases, the pressure from the solenoid increases. The LPC solenoid is a normally high variable force solenoid. When current is high, no fluid pressure passes through the solenoid into the control circuits. When current applied to the solenoid is low, full pressure is passed through to the LPC control circuit and the main regulator valve.