The 2003 Jeep Wrangler, part of the TJ generation, represents a pinnacle of rugged, off-road-focused automotive engineering. Renowned for its iconic design and unparalleled trail capability, this compact SUV is built on a robust body-on-frame chassis, offering a durable platform for adventure. Key features include removable doors and tops, enhancing the open-air driving experience, and a solid front axle, a hallmark of its legendary off-road prowess. Whether tackling challenging terrain or navigating daily commutes, the Wrangler is engineered for reliability and built to withstand demanding conditions, embodying Jeep's enduring legacy of adventure. This comprehensive factory service manual provides essential guidance for the maintenance, repair, and diagnosis of your 2003 Jeep Wrangler. Covering a vast array of systems, including detailed engine repair procedures for both the 4.0L Inline-6 and 2.4L 4-Cylinder engines, fuel and emissions, cooling, drivetrain, suspension, brakes, and electrical systems, this manual serves as an indispensable resource. It details routine maintenance, component removal and installation, and in-depth troubleshooting guides, complete with wiring diagrams and technical specifications. This manual is designed to empower owners and professional technicians alike in preserving the performance and longevity of their vehicle. 🏷️ Basic Information Identification Make: Jeep Model: Wrangler Year: 2003 Generation Generation Designation: TJ (Phase II) Codes Chassis Code: TJ 👋 Introduction Market Position Segment: Compact/Mid-size SUV (Off-Road Focused) Competitive Analysis Key Competitors 2003: Toyota 4Runner, Nissan Xterra, Land Rover Discovery, Ford Explorer Key Features Vehicle Identity: Iconic off-road capability, robust construction, removable doors and top, solid front axle (on most models). Manual Value Proposition Target Audience: Jeep Wrangler TJ owners performing maintenance, repairs, modifications, or seeking in-depth technical understanding. Also valuable for professional mechanics. 📋 Manual Details Coverage Areas Systems Covered: Engine (including repair, timing, lubrication), Fuel and Emissions, Cooling and Heating, Transaxle (manual and automatic), Clutch, Differential, Driveshaft, Steering, Suspension, Brakes (including ABS), Body, Heater and Air Conditioning, Automatic Climate Control, Electrical, Supplemental Restraint System (SRS), Engine Repair, Air Conditioning, Exhaust Emissions Control, Ignition, Wiring Diagrams Page Count Estimated Page Count: Approximately 1500-2000 pages (typical for a comprehensive factory service manual) Manual Type Manual Type: Factory Service Manual / Workshop Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Systems: Engine Removal/Installation, Cylinder Head/Valve Train, Engine Block, Engine Lubrication, Intake Manifold/Exhaust System, Cooling and Heating, Fuel and Emissions, Ignition, Valve Timing Procedures, Chain & Gear Replacement, Tensioner Adjustments, Tensioner Release & Reset Methods, Chain Routing & Sprocket/Gear, Valve Timing Marks Procedures Included Routine Maintenance: Tune-up Procedures, Fluid Checks and Changes, Filter Replacements, Belt Inspection and Replacement, Spark Plug Service Repair And Rebuild: Comprehensive Engine Repair, Cylinder Head Overhaul, Engine Block Machining, Transmission Rebuild (Manual & Automatic), Differential Service, Brake System Overhaul, Steering System Repair, Suspension Component Replacement, HVAC System Repair, Electrical System Diagnosis and Repair Diagnostics: Troubleshooting Guides, Diagnostic Trouble Codes (DTCs), Electrical Schematics, System Testing Procedures Installation: Component Removal & Installation, Body Panel Replacement, Accessory Installation Technical Depth Depth Of Information: In-depth coverage from basic maintenance and tune-ups to complete engine, transmission, and driveline rebuilds, including detailed diagnostic procedures, electrical schematics, and specifications. Suitable for professional technicians and experienced DIY enthusiasts. 📊 Manual Specifications File Format File Format: PDF Print Quality Print Quality: High Resolution, Clear Illustrations and Diagrams Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) Searchability Searchable Text: Likely Searchable Text (common for professionally produced PDFs) ⚙️ Engine Specifications Primary Engine Engine 1 Code: 4.0L Inline-6 (e.g., ERH) Engine 1 Displacement: 3952 cc (241 cu in) Engine 1 Configuration: Inline 6-Cylinder, Overhead Valve (OHV) Engine 1 Horsepower: 190 hp @ 4600 rpm (approx.) Engine 1 Torque: 235 lb-ft @ 3200 rpm (approx.) Engine 1 Fuel System: Electronic Multi-Point Fuel Injection (MPI) Engine 1 Bore X Stroke: 98.5 mm x 86.7 mm (3.88 in x 3.41 in) (approx.) Engine 1 Compression Ratio: 8.75:1 (approx.) Engine 2 Engine 2 Code: 2.4L 4-Cylinder (e.g., EDZ) Engine 2 Displacement: 2429 cc (148 cu in) Engine 2 Configuration: Inline 4-Cylinder, Single Overhead Cam (SOHC) Engine 2 Horsepower: 150 hp @ 5200 rpm (approx.) Engine 2 Torque: 170 lb-ft @ 4000 rpm (approx.) Engine 2 Fuel System: Electronic Multi-Point Fuel Injection (MPI) Engine 2 Bore X Stroke: 87.5 mm x 100.0 mm (3.44 in x 3.94 in) (approx.) Engine 2 Compression Ratio: 9.1:1 (approx.) 🔧 Transmission Standard Transmission Standard Engine 4.0L: NV3550 5-Speed Manual Transmission Transmission Standard Engine 2.4L: AX-5 5-Speed Manual Transmission Optional Transmission Optional Engine 4.0L: 42RLE 4-Speed Automatic Transmission Transmission Optional Engine 2.4L: 30RH 3-Speed Automatic Transmission Features Transfer Case: NP231 Command-Trac (standard) or optional NP241OR Rock-Trac (Rubicon models) Gear Ratios Nv3550: 1st: 3.75, 2nd: 2.14, 3rd: 1.34, 4th: 1.00, 5th: 0.76, Reverse: 3.75 (approx.) Gear Ratios 42Rle: 1st: 2.804, 2nd: 1.532, 3rd: 1.000, 4th: 0.715, Reverse: 2.142 (approx.) Fluid Specifications Manual Transmission Fluid: GL-3 or GL-4 75W-90 (e.g., Mopar...