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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1410 (ENGINE CONTROL SYSTEM - 4.2L (INTRODUCTION))REPAIR INSTRUCTIONSENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENTREMOVAL PROCEDURE
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Removal Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Removal Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.
  1. Turn the engine OFF.
    2. CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices.
  2. Disconnect the negative battery terminal.
  3. Drain coolant below the level of the ECT sensor. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) in Engine Cooling.
    4. Fig 1: Disconnecting/Connecting ECT Sensor Electrical Connector
    GM726805Courtesy of GENERAL MOTORS CORP.
  4. Disconnect the ECT sensor electrical connector (1).
  5. Remove the drive belt and the generator. Refer to Generator Replacement (4.2L Engine) or Generator Replacement (5.3L Engine) in Engine Electrical.
    6. Fig 2: Removing/Installing ECT Sensor
    GM726806Courtesy of GENERAL MOTORS CORP.
  6. Carefully remove the ECT sensor (1).
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.