Torque Converter Clutch Pulse Width Modulated Solenoid Valve
The torque converter clutch (TCC) solenoid valve is a normally closed, pulse width modulated (PWM) solenoid used to control the apply and release of the converter clutch. The TCM operates the solenoid with a negative duty cycle at a fixed frequency of 42 Hz to control the rate of TCC apply/release. The solenoid's ability to ramp the TCC apply and release pressures results in smoother TCC operation.
When vehicle operating conditions are appropriate to apply the TCC, the TCM immediately increases the duty cycle to approximately 42 percent. The TCM then ramps the duty cycle up to approximately 90 percent to achieve full TCC apply pressure. The rate at which the TCM increases the duty cycle controls the TCC apply. Similarly, the TCM also ramps down the TCC solenoid duty cycle to control the TCC release.
Note that the duty cycles in the graph are for example only. Actual duty cycles vary depending on the vehicle application and the vehicle operating conditions.
The TCC solenoid valve resistance should measure between 10-11 ohms when measured at 20°C (68°F). The resistance would measure approximately 16 ohms at 150°C (300°F).