Torque Converter Clutch (TCC) Solenoid
The torque converter clutch (TCC) solenoid is a normally closed, pulse width modulated (PWM) solenoid used to control apply and release of the torque converter clutch (TCC). The PCM/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 TCC apply and release pressures results in a smoother TCC operation.
When vehicle operating conditions are appropriate to apply TCC, the PCM/TCM immediately increases duty cycle to approximately 68%. The PCM/TCM then ramps duty cycle up to approximately 93% to achieve full TCC apply pressure. The rate at which the PCM/TCM increases duty cycle controls TCC apply. Similarly, the PCM/TCM also ramps down TCC solenoid duty cycle to control TCC release.
Some operating conditions prevent or enable the TCC apply under various conditions. Also, if the PCM/TCM receives a high voltage signal from the brake switch indicating that brake pedal is depressed, the PCM/TCM immediately releases the TCC.
The TCC solenoid 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).