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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 253 (ENGINE CONTROLS - SYSTEM & COMPONENT TESTING - 8.1L)FUEL SYSTEMSFUEL PUMP ELECTRICAL CIRCUIT DIAGNOSISCIRCUIT DESCRIPTION
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Circuit Description

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Circuit Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

When the ignition is turned on, the PCM will turn on the in-tank fuel pump. The in-tank fuel pump will remain on as long as the engine is cranking or running and PCM is receiving reference pulses. If there are no reference pulses, PCM will turn the in-tank fuel pump off 2 seconds after ignition is turned on or 2 seconds after engine stops running.

RENDER: 1.0x

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.