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
Engine Electrical
- Specifications (Engine Electrical)
- Schematic And Routing Diagrams (Engine Electrical)
- Component Locator (Engine Electrical)
- Diagnostic Information And Procedures (Engine Electrical)
- Diagnostic Starting Point - Engine Electrical (Engine Electrical)
- Diagnostic System Check - Engine Electrical (Engine Electrical)
- Scan Tool Data List (Engine Electrical)
- Scan Tool Data Definitions (Engine Electrical)
- Diagnostic Trouble Code (DTC) List (Engine Electrical)
- DTC P0562
- DTC P0563
- DTC P0615
- Circuit Description (Engine Electrical)
- Conditions For Running The DTC (Engine Electrical)
- Conditions For Setting The DTC (Engine Electrical)
- Action Taken When The DTC Sets (Engine Electrical)
- Conditions For Clearing The Mil/DTC (Engine Electrical)
- Diagnostic Aids (Engine Electrical)
- Test Description (Engine Electrical)
- DTC P1637
- DTC P1638
- Symptoms - Engine Electrical (Engine Electrical)
- Battery Inspection/Test (Engine Electrical)
- Battery Charging (Engine Electrical)
- Battery Electrical Drain/Parasitic Load Test (w/o BCM)
- Battery Common Causes Of Failure (Engine Electrical)
- Charging System Test (Engine Electrical)
- Charge Indicator Always On (8.1 L)
- Charge Indicator Always On (6.5L)
- Charge Indicator Inoperative (Engine Electrical)
- Generator Noise Diagnosis (Engine Electrical)
- Starter Solenoid Does Not Click (Engine Electrical)
- Starter Solenoid Clicks, Engine Does Not Crank (Engine Electrical)
- Engine Cranks Slowly (Engine Electrical)
- Starter Motor Noise Diagnosis (Engine Electrical)
- Repair Instructions (Engine Electrical)
- Battery Negative Cable Disconnect/Connect Procedure (Single Battery)
- Battery Negative Cable Disconnect/Connect Procedure (Auxiliary Battery)
- Battery Negative Cable Replacement (6.5L Engine)
- Battery Negative Cable Replacement (8.1L Engine)
- Battery Negative Cable Replacement - Auxiliary (Engine Electrical)
- Battery Positive Cable Replacement (6.5L Engine)
- Battery Positive Cable Replacement (8.1L Engine)
- Battery Positive Cable Replacement - Auxiliary (Engine Electrical)
- Battery Replacement (Engine Electrical)
- Battery Replacement - Auxiliary (Engine Electrical)
- Battery Tray Replacement (Engine Electrical)
- Battery Tray Replacement - Auxiliary (Engine Electrical)
- Battery Relay Replacement - Auxiliary (Engine Electrical)
- Ground Strap Replacement (Engine Electrical)
- Starter Motor Replacement (L65)
- Starter Motor Replacement (L18)
- Starter Shield Replacement (Engine Electrical)
- Generator Bracket Replacement (L65)
- Generator Bracket Replacement (L18)
- Generator Bracket Replacement - Auxiliary (Engine Electrical)
- Generator Brace Replacement (Engine Electrical)
- Generator Brace Replacement - Auxiliary (Engine Electrical)
- Generator Pulley Replacement (Engine Electrical)
- Generator Replacement (L65)
- Generator Replacement (L18)
- Generator Replacement - Auxiliary (Engine Electrical)
- Description And Operation (Engine Electrical)
- Special Tools And Equipment (Engine Electrical)
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.