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.
2009 Hummer H3 AlphaFACTORY OEM SERVICE PROCEDURE
Installation Procedure
- Set the bottom of the ECM (1) into the bracket, and push the top of the ECM against the bracket. Ensure that the tabs (2) secure the ECM (1).
- Connect the engine wiring harness electrical connectors (2) to the ECM.
- Engage the integral CPA retainers on the engine wiring harness electrical connectors.
- Connect the body wiring harness electrical connector (2) to the ECM.
- Engage the integral CPA retainer (1) on the body wiring harness electrical connector.
- If a NEW ECM was installed, the ECM must be programmed. Refer to Control Module References .
- Install the windshield washer solvent container. Refer to Windshield Washer Solvent Container Replacement .
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.
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