GM Service Manual Online
For 1990-2009 cars only
Battery Voltage: The scan tool displays 0.0-16.0 volts. The battery voltage input represents the system voltage measured at the BCM ignition feed input.

Ignition Accessory: Input from ignition switch Accessory circuit. Used to determine power mode. Hot in ACC and ON.

Ignition 0: Input to the control module from the ignition switch indicating the Ignition 0 position. Switch closed (HOT) in ignition switch positions UNLOCK, ACC, ON, and START

Ignition 1: Input to the control module from the ignition switch indicating the Ignition 1 position. Switch closed (HOT) in ignition switch positions ON and START

Ignition 3: Input to the control module from the ignition switch indicating the Ignition 3 position. Switch closed (HOT) in ignition switch position ON.

Key in Ignition: Input from ignition switch indicating that the ignition key is inserted into the ignition switch. HOT with key in ignition switch.

Module Part Number: Indicates the module part number.

Seed and Key Timer: Indicates the time remaining for programming functions.

Software Part Number: Part number of component program or the ECU. Used to determine applicability to vehicle RPO content.