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.
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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1648 (LIGHTING SYSTEMS)DIAGNOSTIC INFORMATION AND PROCEDURESDTC 002TEST DESCRIPTION
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Test Description
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Test Description
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- Always perform the lighting diagnostic system check before attempting to diagnose the DTC.
- This step performs the BCM Input/Output test. This test energizes and de-energizes the courtesy lights turn off during this test the courtesy lights supply voltage circuit. If the courtesy lights turn off during this test the courtesy lights supply voltage circuit is not shorted to battery positive voltage or ground.
- Tests the courtesy lights supply voltage circuit of the BCM for a short to battery positive voltage.
- Tests the courtesy lights supply voltage circuit of the interior lamps override switch for a short to battery positive voltage.
RENDER: 1.0x
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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.