TCC Control Valve
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
A spring force holds the valve in the release position. TCC feed limit fluid is routed into the release fluid circuit. Fluid returns from the converter in the apply fluid circuit. This fluid is routed through the valve and into the cooler fluid circuit.