Maintain and repair your GMC Sierra 2500 or 3500 with confidence using the Haynes Repair Manual covering 2020 through 2024 models. This manual includes full in-book coverage for 6.6L L5P diesel engines, plus online access to service data for 6.6L L8T gasoline engines.
Designed for both DIYers and professional technicians, this manual features detailed, step-by-step instructions and hundreds of illustrations covering maintenance, engine overhaul, transmission service, and complex electrical troubleshooting. The included online content expands coverage with interactive wiring diagrams, system diagnostics, and up-to-date technical information.
Haynes manuals are trusted worldwide for clear explanations and expert repair information, helping you save money and keep your Sierra running safely and reliably.

Table of ContentsSafety First
Vehicle Identification Numbers
Jacking and Lifting
Buying Parts
Fluid Level Checks
Tire and Tire Pressure Checks
Lubricants, Fluids, and Tire Pressures
Booster Battery (Jump) Starting
Key Fob Battery Replacement
Troubleshooting
Acronyms
Fraction/Decimal/Millimeter Equivalents
Chapter 1 – Routine Maintenance and Servicing
Chapter 2 – Engine Repair Procedures
Chapter 3 – Cooling, Heating, and Air Conditioning Systems
Chapter 4A – Fuel and Exhaust Systems
Chapter 4B – Emission Control Systems
Chapter 5A – Starting and Charging Systems
Chapter 5B – Pre-Heating System
Chapter 6 – Automatic Transmission
Chapter 7 – Transfer Case
Chapter 8 – Driveshafts, Halfshafts, and Axles
Chapter 9 – Braking System
Chapter 10 – Suspension and Steering
Chapter 11 – Bodywork and Fittings
Chapter 12 – Body Electrical System
Chapter 13 – Wiring Diagrams