The Torque Converter Clutch (TCC) PC Solenoid is a "normally-low", electronic pressure regulator used to control the apply and release of the torque converter clutch based on current flow through its coil windings. The TCC PC solenoid regulates actuator feed limit fluid pressure to the TCC regulator valve, located in the lower valve body, and provides a signal
pressure to shift the TCC control valve, located in the pump, to the apply position. When the TCM determines to apply the TCC, the TCC PC solenoid is commanded to specific pressures, dependent on vehicle operating conditions,
resulting in a smooth apply or release of the TCC. The solenoid's ability to "Ramp" the TCC apply and release pressures result in a smoother TCC operation. When vehicle operating conditions are appropriate to apply the TCC, the TCM increases current flow to allow the TCC PC solenoid to increase PCS TCC fluid pressure, to move the TCC control valve to the apply
position, and move the TCC regulator valve to the regulating position to regulate fluid pressure porportional to solenoid pressure. Release pressure is directed to exhaust, and regulated apply pressure is directed to the apply side of the converter clutch plate/damper assembly. The TCM then increases the pressure to control a slippage of 20-80 RPM between the clutch plate and converter cover. This "Ramping" procedure provides improved dampening of engine vibrations and allows the TCC to apply at low engine speeds in 2nd, 3rd, 4th,5th and 6th gear.