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 DIAGNOSISACCESSORIES & EQUIPMENTINTERIOR/ILLUMINATION LIGHTSLIGHTING SYSTEMS
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Lighting Systems
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Lighting Systems
- Specifications
- Schematic and Routing Diagrams
- Component Locator
- Diagnostic Information and Procedures
- Diagnostic Starting Point - Lighting Systems
- Diagnostic System Check - Lighting Systems
- Scan Tool Output Controls
- Scan Tool Data List
- Scan Tool Data Definitions
- Diagnostic Trouble Code (DTC) List
- DTC B0951: Dimming Circuit
- DTC B1480: Battery Rundown Protection Circuit Malf
- DTC B2527: Front Fog Lamp Circuit Low
- DTC B2530: Front Foglamps Control Circuit
- DTC B2540: Rear Foglamps Control Circuit
- DTC B2550: Backup Lamps Control Circuit
- DTC B2575: Headlamp Control Circuit
- DTC B2580: Headlamp High Beam Control Circuit
- DTC B2585: Parklamp Control Circuit Malfunction
- DTC B2610: Passenger Compartment Dimming 1 Circuit
- DTC B2615: Passenger Compartment Dimming 2 Circuit
- DTC B2620: Display Dimming Input Circuit
- DTC B2625: Display Dimming Pulse Width Modulation (PWM) Output Circuit
- DTC B2645: Ambient Light Sensor Circuit
- DTC B3801: Passenger Compartment Lamp Request Circuit
- DTC B3802: Parklamps Request Circuit
- Symptoms - Lighting Systems
- Backup Lamps Always On
- Backup Lamps Inoperative
- Clearance Lamps Inoperative
- Cornering Lamps Always On
- Cornering Lamps Inoperative
- Courtesy Lamps Always On
- Courtesy Lamps Inoperative
- Daytime Running Lamps (DRL) Defeat Inoperative
- Daytime Running Lamps (DRL) Inoperative
- Daytime Running Lamps (DRL) On with Park Brake Applied
- Fog Lamp Indicator Inoperative
- Fog Lamps Always On
- Fog Lamps Inoperative
- Fog Lamps Always On - Rear
- Fog Lamps Inoperative - Rear
- Hazard Lamps Always On
- Hazard Lamps Inoperative
- Headlamp Switch On Indicator Always On
- Headlamp Switch On Indicator Inoperative
- Headlamps Always On - Low or High Beam
- Headlamps Inoperative - High Beams
- Headlamps Inoperative - Low Beams
- Headlamps Inoperative - Flash to Pass
- Headlight Leveling Inoperative
- High Beam Indicator Always On
- High Beam Indicator Inoperative
- Interior Backlighting Does Not Dim
- Interior Backlighting Inoperative
- License Lamps Inoperative
- Marker Lamps Inoperative
- Memory/Heated Seat Switch Backlighting Inoperative
- Park Lamps Inoperative
- Stop Lamps Always On
- Stop Lamps Inoperative
- Tail Lamps Inoperative
- Tail, Marker, and License Lamps Always On
- Tail, Marker, and License Lamps Inoperative
- Turn Signal Lamps and/or Indicators Always On or Flashing
- Turn Signal Lamps and/or Indicators Inoperative
- Vanity Mirror Lamp(s) Inoperative
- Repair Instructions
- Stop Lamp Switch Replacement
- Headlamp Switch Replacement
- Ambient Light Sensor Replacement
- Hazard and Turn Signal Flasher Replacement
- Dome and Reading Lamp Bulb Replacement
- Vanity Mirror Lamp Bulb Replacement
- Dome Lamp Replacement
- Headlamp Replacement (Chevrolet)
- Headlamp Replacement (Oldsmobile)
- Headlamp Replacement (GMC)
- Headlamp Bulb Replacement
- Headlamp Aiming
- Fog Lamp Replacement - Front (GMC/Chevrolet)
- Fog Lamp Replacement - Front (Oldsmobile)
- Fog Lamp Bulb Replacement - Front
- Fog Lamp Aiming Procedure
- Park/Turn Signal/Side Marker Lamp Bulb Replacement (GMC)
- Park/Turn Signal/Side Marker Lamp Bulb Replacement (Chevrolet)
- Park/Turn Signal/Side Marker Lamp Bulb Replacement (Oldsmobile)
- Cornering Lamp Replacement (GMC/Oldsmobile)
- Cornering Lamp Bulb Replacement (GMC)
- Cornering Lamp Bulb Replacement (Oldsmobile)
- Clearance Lamp Replacement
- High Mounted Stop Lamp Replacement
- Backup Lamp Replacement (GMC)
- Backup Lamp Bulb Replacement (GMC)
- License Lamp Replacement
- Tail Lamp Replacement
- Tail Lamp Bulb Replacement
- Side Marker Lamp Replacement (Oldsmobile)
- Description and Operation
- Special Tools and Equipment
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.