Torque Converter Clutch Solenoid Valve
WARNING: This page is about a different car, the 2009 GMC Yukon and 2009 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used to control torque converter clutch apply and release. When grounded (energized) by the transmission control module (TCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the TCC solenoid valve into the apply position.