2012 GMC Sierra 3500 HD Service and Repair Manual

2012 GMC Sierra 3500 HD service and repair manual — a detailed, factory-style reference for maintenance, diagnostics, and repair. Use it to confirm correct procedures, specifications, and system coverage before you start work.

Designed for technicians and DIY owners, this manual helps you troubleshoot accurately, follow step-by-step repair procedures, and reference wiring diagrams and system sections quickly while you work.

What’s included

• Step-by-step repair procedures and service information
• Specifications and reference data (where provided)
• Wiring diagrams and electrical sections
• Powertrain, brakes, steering, suspension, HVAC and more

Trims covered

• WT Crew Cab Pickup 4-Door
• SLT Crew Cab Pickup 4-Door
• SLT Cab & Chassis 4-Door
• WT Extended Cab Pickup 4-Door
• SLE Extended Cab Pickup 4-Door
• WT Cab & Chassis 4-Door
• SLE Cab & Chassis 4-Door
• WT Cab & Chassis 2-Door
• Denali Crew Cab Pickup 4-Door
• SLE Cab & Chassis 2-Door
• SLE Crew Cab Pickup 4-Door
• SLT Extended Cab Pickup 4-Door
• WT Standard Cab Pickup 2-Door
• SLE Standard Cab Pickup 2-Door

Engines covered

• 6.6L 6599CC 403Cu. In. V8 DIESEL OHV Turbocharged
• 6.0L 5967CC 364Cu. In. V8 GAS OHV Naturally Aspirated
• 6.0L 5967CC 364Cu. In. V8 FLEX OHV Naturally Aspirated

Index / Table of contents

• Body
• Brakes
• Chassis Electrical
• Driveline
• Engine Cooling
• Engine Electrical
• Engine Mechanical
• Engine Performance & Emission Controls
• Fuel System
• General Information & Identification
• Heating, Ventilation, & Air Conditioning
• Hybrid & Electric Vehicle Systems
• Steering
• Suspension
• Transmission, Clutch, & Transfer Case
• Wiring Diagrams