Diagnostic Trouble Code Definitions

2001 Chevrolet Chevy Express G3500, Van Passenger Extended, 6.5 FSECTION Diagnostic Trouble Code Definitions
DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC (1) Description
P0562  Low System Voltage
P0563  High System Voltage
P1637  Generator Turn On Signal Circuit Voltage Out Of Range
P1638  Pulse Width Modulated Signal Out Of Range
(1) Codes listed in this table are only for testing covered in this article. For complete DTC listing, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
RENDER: 1.0x

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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.