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.
2003 Chevrolet Express 1/2 Ton Van V6-4.3L VIN XFACTORY OEM SERVICE PROCEDURE
Scan Tool Data Definitions
SCAN TOOL DATA DEFINITIONS
Accessory Switch: Input from ignition switch accessory circuit. Used to determine power mode. Hot in ACC and ON.
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 Unlock: 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
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.
Run/Crank: Input to the control module from the ignition switch indicating the Ignition 1 position. Switch closed (HOT) in ignition switch positions ON and
START Software Design Suffix: Details the software version used.
Software Part Number: Part number of the software.
Accessory Switch: Input from ignition switch accessory circuit. Used to determine power mode. Hot in ACC and ON.
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 Unlock: 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
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.
Run/Crank: Input to the control module from the ignition switch indicating the Ignition 1 position. Switch closed (HOT) in ignition switch positions ON and
START Software Design Suffix: Details the software version used.
Software Part Number: Part number of the software.
Factory Service Tools
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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.
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