TCC Control Pulse Width Modulated (PWM) Solenoid Valve
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2006 Saturn Relay, 2006 Pontiac Montana SV6, 2006 Pontiac Grand Prix, 2006 Pontiac G6, and 2006 Chevrolet Uplander. However, it is still accessible from the selected car via links, so may be relevant.
2nd fluid is routed to the TCC control PWM solenoid. Under normal operating conditions the TCC control PWM solenoid is OFF in Second gear and blocks 2nd fluid from entering the TCC signal fluid circuit.