Diagnostic Trouble Code (DTC) List

1999 GMC Forward Control 5.7 R, AutomaticSECTION Diagnostic Trouble Code (DTC) List
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic Trouble Code (DTC) List

DTC Diagnostic Procedure Module
B0165 DTC B0165 or B0166  HVAC Control Module
B0166 DTC B0165 or B0166  HVAC Control Module
B0233 DTC B0233  HVAC Control Module
B0408 DTC B0408 or B0418  HVAC Control Module
B0418 DTC B0408 or B0418  HVAC Control Module
B3933 DTC B3933  HVAC Control Module
P0530 DTC P0530, P0532, or P0533  PCM
P0532 DTC P0530, P0532, or P0533  PCM
P0533 DTC P0530, P0532, or P0533  PCM
P0645 DTC P0645, P0646, or P0647  PCM
P0646 DTC P0645, P0646, or P0647  PCM
P0647 DTC P0645, P0646, or P0647  PCM
RENDER: 1.0x

NO RELATED

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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.