2003 Chevrolet Chevy Express H2500FACTORY OEM SERVICE PROCEDURE

Charging DTCS

CHARGING DIAGNOSTIC TROUBLE CODE (DTC) LIST

DTC Description
DTC P0562 LOW SYSTEM VOLTAGE
DTC P0563 HIGH SYSTEM VOLTAGE
DTC P1637 GENERATOR TURN-ON SIGNAL CIRCUIT VOLTAGE OUT OF RANGE
DTC P1638 PULSE WIDTH MODULATED SIGNAL 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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.