Torque Converter Clutch

TCC Solenoid Valve 

Under normal operating conditions, in Overdrive Range-Third Gear, the PCM keeps the normally open TCC solenoid valve de-energized. Converter feed fluid exhausts through the open solenoid, and spring force keeps the converter clutch apply valve in the release position. However, at speeds above approximately 121 km/h (75 mph), with the transmission still in third gear, the PCM will command TCC apply in third gear. Refer to Overdrive Range, Fourth Gear - Torque Converter Clutch Applied  for more information on TCC apply.