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.
2008 Hummer H3 L5-3.7LFACTORY OEM SERVICE PROCEDURE
Powertrain Management: Technical Service Bulletins
- Recalls
- Customer Interest
- Engine Controls - MIL ON/DTC P2135 Set
- Ignition System - Runs Rough MIL/ON DTC P0300/0306
- Drivetrain - 4WD Message Light On DTC C0327 Set
- Electrical - MIL/DTC P2138 with Reduced Engine Power
- Fuel System - Driveability Issues/MIL ON/Multiple DTC's
- A/T - No Movement in Drive or Third
- Electrical - Warning Lamps/Electrical Malfunctions
- By Symptom
- Abnormal wear/deterioration
- Customer Interest
- Engine Controls - MIL ON/DTC P2135 Set
- Ignition System - Runs Rough MIL/ON DTC P0300/0306
- Drivetrain - 4WD Message Light On DTC C0327 Set
- Electrical - MIL/DTC P2138 with Reduced Engine Power
- Fuel System - Driveability Issues/MIL ON/Multiple DTC's
- A/T - No Movement in Drive or Third
- Electrical - Warning Lamps/Electrical Malfunctions
- Driveability
- False instrument warning light/gauges
- Inoperative
- Recalls
- All Technical Service Bulletins
- Engine Controls - MIL ON/DTC P2135 Set
- Recall - Directional Indicator Rework
- Ignition System - Runs Rough MIL/ON DTC P0300/0306
- Drivetrain - 4WD Message Light On DTC C0327 Set
- Aftermarket Parts - Non GM Parts And Accessories Info
- Engine, A/T Controls - Non-GM Calibration ID
- Electrical - MIL/DTC P2138 with Reduced Engine Power
- A/T Controls - Procedure To Take Snapshot Data
- Fuel System - Driveability Issues/MIL ON/Multiple DTC's
- A/T Controls - DTC P0756 Diagnostics
- Fuel System - E85 Fuel Usage Precaution
- Fuel System - GM Fuel Systems Treatment Plus(R)
- Fuel System - E85 Fuel Usage Information
- Engine/Fuel System - Additive Information
- A/T - No Movement in Drive or Third
- Fuel System - TOP TIER Detergent Gasoline Information
- Fuel System - TOP TIER Detergent Gasoline
- Exhaust System - Sulfur Odor Explanation
- Electrical - Warning Lamps/Electrical Malfunctions
- Engine - Unnecessary Flushing Services/Recommendations
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.