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 GMC Jimmy 2D Utility, Part Time, AutomaticFACTORY OEM SERVICE PROCEDURE
Charging DTCS
CHARGING DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description |
|---|---|
| DTC B1327 | BATTERY/SOURCE VOLTAGE LOW |
| DTC P0562 | LOW SYSTEM VOLTAGE |
| DTC P0563 | HIGH SYSTEM VOLTAGE |
| DTC P0621 | HIGH OR LOW GENERATOR TURN ON SIGNAL |
| DTC P0622 | OUT OF RANGE DUTY CYCLE SIGNAL |
| DTC P1637 | HIGH OR LOW GENERATOR TURN ON SIGNAL |
| DTC P1638 | OUT OF RANGE DUTY CYCLE SIGNAL |
Factory Service Tools
Use the Manual With the Right Hardware
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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.