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 H3T Base, StandardFACTORY OEM SERVICE PROCEDURE

Removal Procedure

Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.

Fig 1: Locating PCM & Engine Wiring Harness PCM Connectors

Courtesy of GENERAL MOTORS CORP.

Disengage the connector position assurance (CPA) retainers.
Disconnect the engine wiring harness ECM connectors from the ECM.

Fig 2: Locating PCM & Body Wiring Harness PCM Connector

Courtesy of GENERAL MOTORS CORP.

Disengage the CPA retainer.
Disconnect the body wiring harness ECM connector from the ECM.

Fig 3: Removing/Installing PCM

Courtesy of GENERAL MOTORS CORP.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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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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