🏷️ Basic Information Identification Make: GMC Model: Sierra 2500 HD Year: 2012 Generation Generation Code: GMT900 Generation Years: 2007-2013 👋 Introduction Market Position Positioning: Heavy-duty truck segment, designed for commercial and demanding towing/hauling applications. Competitive Analysis Competitors: Ford F-250 Super Duty, Ram 2500, Chevrolet Silverado 2500 HD (sister model). Key Features Manual Advantage: Officially licensed, OE-derived information from RepairSurge, providing accurate and up-to-date data for DIY and professional use. Vehicle Advantage: Robust construction, powerful engine options for heavy-duty tasks, towing and payload capacity. Manual Value Proposition Value: Cost-effective alternative to dealership service, empowering owners to maintain and repair their vehicle. 📋 Manual Details Coverage Areas Coverage Scope: Complete Service and Repair Page Count Estimated Page Count: Thousands (digital format, comprehensive) Manual Type Type: Online Service and Repair Manual Software Language Language: English Format Format: Web-based/Online Access (via browser) 📖 Manual Coverage Systems Covered Engine Mechanical: All engine assemblies, including internal components, lubrication, cooling, and exhaust systems. Engine Performance: Fuel delivery, ignition, emissions control, starting and charging systems. Transmission Drivetrain: Manual and automatic transmission systems, transfer case, drive axles, propeller shafts, and differentials. Suspension Steering: Front and rear suspension components, steering gear, power steering system, wheel alignment. Brakes: Hydraulic brake systems (front and rear discs/drums), ABS, parking brake, hydraulic control unit. Electrical System: Battery, starting, charging, lighting, instruments, warning indicators, body control module (BCM). HVAC: Heating, Ventilation, and Air Conditioning (HVAC) system components and operation. Body Interior: Body panels, doors, windows, seats, interior trim, glass, and related components. Chassis: Frame construction, collision repair, underbody components. Diagnostic Information: Diagnostic Trouble Codes (DTCs), symptom-based diagnostics, troubleshooting flowcharts. Procedures Included Maintenance Procedures: Oil changes, filter replacements, fluid checks and changes, spark plug replacement, belt inspections and replacement. Repair Procedures: Component removal, disassembly, inspection, repair, reassembly, and installation for all covered systems. Troubleshooting Guides: Step-by-step diagnostic procedures for identifying and resolving common and uncommon vehicle faults. Wiring Diagrams: Detailed electrical wiring diagrams for all vehicle circuits. Specifications Data: Torque specifications, clearances, fluid capacities, pressure readings, and other critical data. Technical Depth Depth: Comprehensive, from routine maintenance to major component overhauls and diagnostics. Manual Depth Detail Diagnostic Procedures: Includes detailed symptom-based troubleshooting, diagnostic trouble code (DTC) explanations, and repair procedures for diagnosing electrical and mechanical faults. 📊 Manual Specifications File Format Digital Requirements: Requires an active internet connection and a compatible web browser on any PC, laptop, smartphone, or tablet. Print Quality Print Ability: While digital, sections can typically be printed for offline reference (quality dependent on user printer). Binding Type Binding: N/A (Digital Online Access) Paper Type Paper Type: N/A (Digital Online Access) Access Duration Subscription Period: 1 Year (with discounts available for renewal) ⚙️ Engine Specifications Primary Engine Gas Engine Code Gas: L96 (Vortec 6.0L V8 SFI FlexFuel) Displacement Gas: 5967 cc (364 cubic inches) Horsepower Gas: 360 hp @ 5400 rpm Torque Gas: 380 lb-ft @ 4200 rpm Fuel System Gas: Sequential Fuel Injection (SFI), FlexFuel capable. Block Material Gas: Cast Iron Cylinder Head Gas: Aluminum Primary Engine Diesel Engine Code Diesel: V8DOHC (Duramax 6.6L Turbo Diesel V8 - RPO LML) Displacement Diesel: 6599 cc (403 cubic inches) Horsepower Diesel: 397 hp @ 3000 rpm Torque Diesel: 765 lb-ft @ 1600 rpm Fuel System Diesel: High-pressure Common Rail Direct Injection with Turbocharger. Block Material Diesel: Cast Iron Cylinder Head Diesel: Aluminum Engine Technology Diesel: Variable Geometry Turbocharger (VGT), Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR) system (for LML). 🔧 Transmission Standard Transmission Type Standard: Allison 1000 6-speed automatic (with Diesel engines) Optional Transmission Type Optional: ZF S6-650 6-speed manual (less common, typically with gas engine) Features Transmission Features: Heavy-duty construction, Tow/Haul mode, grade braking, electronic transmission range selection (ETRS). 📐 Dimensions Exterior Wheelbase Standard: 143.5 inches (3645 mm) (Regular Cab, Long Bed) Wheelbase Extended: 153.7 inches (3904 mm) (Extended/Crew Cab, Standard Bed) Wheelbase Longest: 167.5 inches (4255 mm) (Crew Cab, Long Bed) Weights Curb Weight Approx: 6,300 - 7,500 lbs (2858 - 3402 kg) (Varies by configuration) Gvwr Gross Vehicle Weight Rating: Up to 9,200 lbs (4173 kg) or 10,000 lbs (4536 kg) depending on configuration. Gcwr Gross Combined Weight Rating: Up to 22,000 lbs (9979 kg) for diesel models. 🛡️ Safety Features Ratings NHTSA Rollover Rating: 4 out of 5 stars (typical for this generation, check specific test data). Active Features Active Safety: StabiliTrak (Traction Control and Electronic Stability Control), Trailer Sway Control, Anti-lock Braking System (ABS). Passive Features Passive Safety: Frontal airbags, Side-impact airbags (optional/standard on some trims), Seatbelt pretensioners. 💡 Technology Features Infotainment Infotainment System: Available touch-screen infotainment systems with navigation, Bluetooth connectivity, and SiriusXM Satellite Radio. Driver Assistance Driver Assist Features: Integrated trailer brake controller (optional), rearview camera (optional). Connectivity Connectivity Options: OnStar capabilities (subscription-based), USB/Auxiliary input jacks. 🔧 Maintenance Service Intervals Oil Change Interval: 5,000 miles (8,000 km) for gasoline, 7,500 miles (12,000 km) for diesel, or...