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
Starting DTCS
STARTING AIR BAG DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description |
|---|---|
| DTC B1327 | Low Voltage |
| DTC B1328 | High Voltage |
| DTC P0562 | PCM Detects An Improper Voltage Below 11 Volts |
| DTC P0563 | PCM Senses System Voltage Is Above 19 Volts |
| DTC P0615 | Starter Relay Control Circuit Voltage |
| DTC P1637 | Improper Voltage On Generator L-Terminal Circuit |
| DTC P1638 | PWM Signal Is Out Of Range |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.