🏷️ Basic Information

Make:

Jeep

Model:

Wrangler

Year:

2003

Chassis Code:

TJ

👋 Introduction

Positioning:

The Jeep Wrangler (TJ) is a highly capable off-road vehicle, known for its iconic design and ruggedness. This manual caters to owners and mechanics seeking detailed repair and maintenance information for this specific generation.

Competition:

While the Wrangler occupies a unique niche, competitors in the broader SUV/off-road segment for that era included models like the Toyota 4Runner, Nissan Xterra, and Land Rover Defender (though the Defender's availability varied by market).

Jeep Tj Features:

Solid front and rear axles, coil spring suspension, removable doors and roof, legendary off-road capability.

📋 Manual Details

Manual Type:

Digital Service and Repair Manual

Language:

English

Format:

Digital (likely PDF)

📖 Manual Coverage

Engine:

Comprehensive coverage for all gasoline engine variants.

Transmission:

Detailed information for manual and automatic transmissions.

Drivetrain:

Four-wheel drive system, transfer case, axles, differentials.

Suspension:

Front and rear suspension components, shock absorbers, springs, steering.

Brakes:

Hydraulic brake system, ABS, rotor, caliper, and pad replacement.

Electrical System:

Battery, charging system, ignition, lighting, instrumentation, power accessories.

Fuel System:

Fuel pump, injectors, lines, tank, evaporative emission control.

Cooling System:

Radiator, water pump, thermostat, hoses, fan.

Exhaust System:

Catalytic converter, muffler, pipes, emissions control.

Body And Frame:

Body panels, doors, hood, tailgate, chassis repair.

Interior:

Seats, dashboard, trim panels, HVAC system.

Maintenance:

Regular scheduled maintenance, fluid changes, filter replacements.

Diagnostics:

Troubleshooting guides, diagnostic trouble codes (DTCs), symptom analysis.

Repair:

Step-by-step repair procedures for all major components.

Rebuilds:

Detailed instructions for engine, transmission, and transfer case rebuilds.

Adjustment:

Calibration and adjustment of various systems (e.g., steering alignment, parking brake).

Troubleshooting Charts:

Comprehensive charts to identify and resolve common issues.

Depth:

Comprehensive, suitable for professional technicians and experienced DIY enthusiasts.

📊 Manual Specifications

File Type:

PDF

Searchability:

Text-searchable for quick information retrieval.

Printability:

Printable pages for in-garage use.

Illustrations:

Likely includes diagrams and illustrations to aid repair.

⚙️ Engine Specifications

Engine Code:

4.0L Inline 6 Cylinder (High Output OHV)

Engine Displacement:

3952 cc (241 cu in)

Bore X Stroke:

3.875 in x 3.414 in (98.4 mm x 86.7 mm)

Compression Ratio:

8.8:1

Horsepower:

190 hp @ 4600 rpm (for 2003 model)

Torque:

235 lb-ft @ 3200 rpm (for 2003 model)

Fuel Type:

Unleaded Regular (87 Octane)

Injection Type:

Sequential Multi-Port Fuel Injection (MPI)

Ignition System:

Distributorless Ignition System (DIS) with coil-on-plug (COP) or waste spark.

Engine Option 2 0L:

2.4L I4 (16 valve, DOHC) - Less common in the TJ generation, primarily earlier models or specific markets.

Engine Option 2 4L Hp:

147 hp @ 5200 rpm

Engine Option 2 4L Torque:

165 lb-ft @ 3600 rpm

🔧 Transmission

Standard Transmission Type:

NV3550 5-speed manual transmission

Optional Transmission Type:

42RLE 4-speed automatic transmission

Transfer Case:

NV231 Command-Trac (part-time, single-speed or two-speed transfer case depending on trim/options)

Axles:

Dana 30 (front), Dana 35c or optional Dana 44 (rear), depending on trim and package.

📐 Dimensions

Wheelbase:

93.4 inches (2372 mm)

Overall Length:

160.5 inches (4077 mm)

Overall Width:

66.7 inches (1694 mm)

Overall Height:

73.9 inches (1877 mm) (with soft top, varies by configuration)

Passenger Volume:

Approx. 75.0 cu ft (2124 L)

Cargo Volume Behind Rear Seat:

Approx. 14.6 cu ft (413 L)

Cargo Volume With Rear Seat Folded:

Approx. 45.2 cu ft (1280 L)

Curb Weight:

Approx. 3300-3700 lbs (1497-1678 kg), varies by configuration.

Gross Vehicle Weight Rating Gvwr:

Approx. 4800 lbs (2177 kg)

🛡️ Safety Features

NHTSA Rollover Rating:

Four-star rating in frontal offset and side impact, often rated for rollover resistance.

ABS:

Anti-lock Braking System (ABS) available on 4-wheel disc brake systems.

Traction Control:

Optional traction control system available on some models.

Airbags:

Driver and front passenger airbags.

Seat Belts:

Three-point front seat belts, two-point rear seat belts (lap belts).

Roll Bar:

Integrated roll cage structure for enhanced occupant protection.

💡 Technology Features

Infotainment System:

Basic AM/FM radio with CD player, optional Infinity sound system. Limited by era; no touchscreens or advanced connectivity.

Driver Assistance Features:

Minimal. Primarily focused on core vehicle operation and safety. ABS was an option.

Connectivity Options:

No factory Bluetooth, USB ports, or smartphone integration. Aftermarket solutions are common.

🔧 Maintenance

Oil Change Interval:

Every 3,000 to 7,500 miles (5,000 to 12,000 km) or 6 months, depending on oil type and driving conditions (refer to manual for specifics).

Engine Air Filter:

Inspect every 15,000 miles (24,000 km), replace as needed.

Spark Plugs:

Replace every 100,000 miles (160,000 km) for platinum-tipped plugs (refer to manual for specific plug type and gap).

Engine Oil Type:

SAE 10W-30 API Certified (for 4.0L engine). Consult manual for specific viscosity under different temperature ranges.

Engine Oil Capacity:

6 US quarts (5.7 Liters) with filter (for 4.0L engine).

Coolant Type:

Chrysler/Dodge/Jeep HOAT (Hybrid Organic Acid Technology) coolant, typically a green or orange color. Mopar or equivalent.

Transmission Fluid Type Auto:

ATF+4 (Automatic Transmission Fluid)

Transmission Fluid Type Manual:

Refer to manual for specific gear oil specification (e.g., SAE 75W-90 GL-3 or GL-4).

Transfer Case Fluid Type:

NP231: Mopar Part No. 04778537 or equivalent synthetic gear lubricant, e.g., SAE 75W-80 or 75W-90 GL-3.

Differential Fluid Type:

Hypoid gear lubricant, SAE 80W-90 API GL-5. Consider limited-slip additive if equipped with a limited-slip differential.

Common Tj Issues:

Crankshaft position sensor failure, rear main seal leaks (especially on the 4.0L), radiator leaks, clutch wear (manual transmissions), rust on body mounts and frame rails, potential for NP231 transfer case chain stretch.

📚 Vehicle History

Jeep Heritage:

Jeep has a long and storied history, originating from military vehicles in World War II and evolving into a symbol of off-road capability and adventure.

Tj Generation:

The TJ generation (1997-2006) marked a significant departure from previous Wranglers by adopting coil-spring suspension and rack-and-pinion steering, improving on-road manners while retaining off-road prowess.

2003 Updates:

While significant redesigns were less common mid-generation, 2003 saw minor refinements and package updates. The 4.0L inline-six remained the dominant engine.

Manufacturing Location:

Toledo, Ohio, USA

🏆 Awards & Recognition

Off Road Awards:

The Jeep Wrangler has consistently been recognized as one of the most capable off-road vehicles by automotive publications and enthusiast groups.

Consumer Satisfaction:

Generally well-regarded for its ruggedness and off-road prowess, though reliability ratings can vary due to its specialized nature and components.