Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
BCM Scan Tool Data Definitions
- Battery Voltage
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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
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The scan tool displays the 8-digit alphanumeric module part number.
- Ignition Accessory
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Input from ignition switch Accessory circuit. Used to determine power mode. Hot in ACC and ON.
- Ignition 0
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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
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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
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Input to the control module from the ignition switch indicating the ignition 3 position. Switch closed (HOT) in ignition switch position ON.
- Julian Date of Build
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This is the day of the year that the module was built.
- Key in Ignition
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Input from ignition switch indicating that the ignition key is inserted into the ignition switch. HOT with key in ignition switch.
- Left Rear Door Ajar Sw.
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Input from the left rear door/rear cargo showing the state of it.
- Right Rear Door Ajar Sw.
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Input from the right rear door indicating door status.
- SWC Switch Voltage
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Indicates the steering wheel controls supply voltage.
- SWC Switch Power
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Indicates if voltage is supplied to the steering wheel controls.
- Year Module Built
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This is the year that the module was built.
NO RELATED
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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.