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 951 (LIGHTING SYSTEMS)
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Section 951 (Lighting Systems)
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Section 951 (Lighting Systems)
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- 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 B1480: Battery Rundown Protection Circuit Malf
- DTC B2527: Front Fog Lamp Circuit Low
- DTC B2537: Rear Foglamps Circuit Low
- 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 B2600: Daytime Running Lamp Control Circuit
- DTC B2610: Passenger Compartment 1 Dimming Circuit
- DTC B2615: Passenger Compartment Dimming 2 Circuit
- DTC B2620: Display Dimming Pulse Width Modulation (PWM) 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
- Cargo Lamp Always On
- Cargo Lamp Inoperative
- Clearance Lamps Inoperative
- Courtesy Lamps Always On
- Courtesy Lamps Inoperative
- Daytime Running Lamps (DRL) Always On
- Daytime Running Lamps (DRL) Inoperative (Domestic)
- Exterior Courtesy Lamp(s) Always On
- Exterior Courtesy Lamp(s) Inoperative
- Fog Lamp Indicator Inoperative
- Fog Lamp Indicator Inoperative - Rear
- Fog Lamps Always On
- Fog Lamps Inoperative
- Fog Lamps Always On - Rear
- Fog Lamps Inoperative - Rear
- Hazard Lamps Always On
- Hazard Lamps Inoperative
- Headlamps Always On - Low or High Beam
- Headlamps Inoperative - High Beams
- Headlamps Inoperative - Low Beams
- Headlamps Inoperative - Low and High 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
- Park, License, and Tail Lamps Always On
- Park, License, and Tail Lamps Inoperative
- Reading Lamp(s) Inoperative
- Roof Beacon Lamp Always On
- Roof Beacon Lamp Inoperative
- Stop Lamps Always On
- Stop 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
- Headlamp Leveling Switch Replacement
- Lamp Switch Assembly Replacement - Front Fog Lamp and Cargo Lamp
- Fog Lamp Switch Replacement - Rear
- Ambient Light Sensor Replacement
- Hazard and Turn Signal Flasher Replacement
- Courtesy Lamp Replacement - Exterior
- Courtesy Lamp/Reflector Replacement - Door
- Instrument Panel (I/P) Compartment Lamp Switch Replacement
- Vanity Mirror Lamp Replacement
- Dome Lamp Replacement
- Underhood Lamp Replacement
- Headlamp Assembly or Headlamp Bulb Replacement (Old Style)
- Headlamp Aiming
- Fog Lamp Replacement - Front
- Fog Lamp Bulb Replacement - Front (Old Style)
- Fog Lamp Bulb Replacement - Rear
- Fog Lamp Aiming Procedure
- Park/Turn Signal Lamp Replacement (Old Style)
- Marker Lamp Replacement - Roof (Center)
- Marker Lamp Replacement - Roof (Outer)
- Marker Lamp Bulb Replacement - Roof (Center)
- Marker Lamp Bulb Replacement - Roof (Outer)
- High Mounted Stop Lamp Replacement
- License Lamp Replacement (Pickup W/O Bumper)
- Tail/Turn Signal Lamp Replacement (Except Stepside)
- Description and Operation
- Special Tools and Equipment
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
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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.