GM Service Manual Online
For 1990-2009 cars only
Battery 1: The scan tool displays 0-25.5 volts. The state of the battery voltage supplied to the body control module (BCM).

Driver Door Switch: The scan tool displays the status of the driver door switch.

Ignition 1 Input: The scan tool displays the state of the ignition 1 Run/Crank input to the BCM.

Ignition 2 Input: The scan tool displays the state of the ignition 2 Acc/Run input to the BCM.

Ignition 3 Input: The scan tool displays the state of the ignition 3 Run input to the BCM.

Key In Ignition: The scan tool displays Yes/No. The BCM receives an input from the ignition switch indicating whether the key is in the ignition or not, with Yes meaning the key is in the ignition.

Liftgate Ajar Switch: The scan tool displays the status of the liftgate switch.

Pass Door Switches: The scan tool displays the status of the passenger doors switches.