GM Service Manual Online
For 1990-2009 cars only
Cruise Control Active: Displays Yes or No. The status of the cruise engaged signal. The cruise control module grounds the circuit when cruise control is on.

TCC Brake Pedal Switch: Displays ON or Off. The status of the cruise release signal circuit. The TCC/Brake pedal switch and the Clutch Pedal Position (CPP) switch if equipped, are normally closed switches, in series, controlling the cruise control cancel circuit.