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.
2003 Hummer H2FACTORY OEM SERVICE PROCEDURE
Battery DTCS
BATTERY AIR BAG DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description |
|---|---|
| DTC B1327 | Battery Voltage Low |
| DTC B1328 | Battery Voltage High |
| DTC P0562 | Voltage At PCM Low |
| DTC P0563 | Voltage At PCM High |
| DTC P0615 | Starter Relay Circuit Voltage |
| DTC P1637 | Improper Voltage Level On Generator L-Terminal |
| DTC P1638 | Generator PWM Signal Is Out Of Range |
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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