Pressure Control Solenoid Valve
WARNING: This page is about a different car, the 2004 Pontiac Sunfire, 2004 Chevrolet Classic, and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The PCM increases the PCS duty cycle in order to increase the operating range of torque signal fluid pressure in Manual Second. This provides increased line pressure for the additional torque requirements during engine compression braking and increased engine load in Manual Second.