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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.
GM Part Number: The module's part number.
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
Key in Ignition: Input from ignition switch indicating that the ignition key is inserted into the ignition switch. HOT with key in ignition switch.
Julian Date of Build: The day of the year when module was built.
SWC Switch Power: Indicates the state of the supply voltage to the steering wheel controls supply voltage.
SWC Switch Voltage: Indicates the steering wheel controls supply voltage.
Year Module Built: The year when module was built.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Scan Tool Data Definitions

Use the Manual With the Right Hardware

When to See a Mechanic