2021 Chevrolet Trailblazer LFACTORY OEM SERVICE PROCEDURE

Engine Control Module Replacement

WARNING: This page is about a different variant/trim than selected.
GM5278836Courtesy of GENERAL MOTORS COMPANY
Callout Component Name
Preliminary Procedure 
Battery Negative Cable Disconnection and Connection
1 Engine Control Module
CAUTION:

Always turn the ignition off when installing or removing the ECM connectors in order to prevent damage to the components.

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Factory Service Tools

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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.