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.
2002 GMC C3500 HD 6.5 F, AutomaticFACTORY OEM SERVICE PROCEDURE
DTC Index
Select a section or procedure below to view factory instructions:
Air Bag DTCSAnti-Lock Brake DTCSAutomatic Transmission (4L60-E) DTCSAutomatic Transmission (4L80-E Light Duty) DTCSAutomatic Transmission (4L80-E Heavy Duty - Diesel 3500 Series/Cab & Chassis) DTCSAutomatic Transmission (4L80-E Heavy Duty - Gasoline 3500 Series/Cab & Chassis) DTCSAutomatic Transmission (ALLISON) DTCSBody Control Module DTCSCellular Communication DTCSCharging DTCSCruise Control DTCSData Link Communication DTCSEngine Performance - 4.3L DTCSEngine Performance - 4.8L, 5.3L & 6.0L DTCSEngine Performance - 6.6L DTCSEngine Performance - 8.1L DTCSHorn DTCSHVAC, Automatic DTCSInstrument Panel DTCSKeyless Entry DTCSLighting DTCSManual Transmission (NV 3500) DTCSManual Transmission (NV 4500) DTCSManual Transmission (ZF S6-650) DTCSPower Door Lock DTCSREATAINED Accessory Power DTCSTheft Deterrent DTCSTransfer Case (NVG 236/246-NP8) DTCS
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.