For 1990-2009 cars

The Transmission Scan Tool Data Definitions contain a brief description of all manual transmission related parameters available on the scan tool. The list is in alphabetical order.

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.
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.