GM Service Manual Online
For 1990-2009 cars only
CPP Switch: This parameter displays the state of the clutch pedal switch circuit input. The scan tool will display APPLIED when the clutch pedal is depressed, and RELEASED when the clutch pedal is released.

Reverse Inhibit Solenoid Command: This parameter displays the commanded state of the reverse inhibit solenoid. When the vehicle speed is greater than 5 km/h (3 mph), the solenoid is commanded ON, inhibiting shifts to Reverse. When the vehicle speed is less than 5 km/h (3 mph), the solenoid is commanded OFF, allowing shifts to Reverse. The scan tool will display ON/OFF.

Vehicle Speed Sensor: This parameter displays the speed at which the vehicle is traveling. The scan tool displays vehicle speed as kilometers per hour (km/h), miles per hour (mph). The vehicle speed is calculated based on the input signal from the vehicle speed sensor.