Diagnostic Trouble Code Definitions

2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Diagnostic Trouble Code Definitions
WARNING: This page is about a different car, the 2003 GMC Savana Special, 2003 GMC Savana Camper Special, 2003 GMC Savana, and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC (1) Description
P0562Β  Low System Voltage
P0563Β  High System Voltage
P1637Β  Generator Turn On Signal Circuit Voltage Out Of Range
P1638Β  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 DIAGNOSTIC TROUBLE CODE DEFINITIONS in BODY CONTROL MODULES - CHEVY EXPRESS & SAVANNA article in COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
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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.