Market Position:
The 2004 Jeep Wrangler TJ represents a direct evolution of the iconic Jeep lineage, prioritizing off-road capability and utilitarian design. This manual caters to owners and independent repair shops seeking authoritative technical data to maintain and repair this specific generation.
Competitive Analysis:
Competes against similarly focused off-road vehicles but distinguishes itself with its raw, open-air experience and legendary four-wheel-drive systems. Manuals for this era are critical due to evolving electronics and complex mechanicals.
Key Features:
Officially licensed, comprehensive coverage, digital format for quick access, detailed schematics and repair procedures, essential for maintaining peak performance and longevity.
Engine Systems:
Engine mechanical, fuel injection, ignition, cooling, lubrication, exhaust
Transmission Drivetrain:
Manual transmission, automatic transmission, transfer case, drive shafts, axles
Suspension Steering:
Front and rear suspension, steering system, power steering
Brakes:
Brake system, ABS (if equipped), parking brake
Electrical Electronics:
Battery, charging system, starting system, lighting, instruments, Body Control Module (BCM), Powertrain Control Module (PCM), diagnostic trouble codes (DTCs)
Body Chassis:
Frame, body panels, doors, windows, seats, interior trim, convertible top
HVAC:
Heating, Ventilation, and Air Conditioning (HVAC) system
Maintenance Procedures:
Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspection and replacement, tire rotation and pressure checks
Repair Procedures:
Engine component replacement (e.g., water pump, alternator), transmission overhaul, brake pad/rotor replacement, suspension component replacement (e.g., ball joints, shocks), exhaust system repair, electrical component diagnosis and replacement
Diagnostic Procedures:
Troubleshooting guides for common symptoms, diagnostic flowcharts, reading and interpreting DTCs, using diagnostic scan tools
Technical Depth:
Comprehensive coverage from routine maintenance to major overhauls and complex diagnostics, including detailed torque specifications, wiring diagrams, and component testing procedures.
Engine Option 1:
4.0L (3952cc) Inline-6 OHV 12-valve, designated 'Power Tech' engine (Code: ERH)
Engine Option 1 Hp:
190 hp @ 4600 rpm
Engine Option 1 Torque:
235 lb-ft @ 3200 rpm
Engine Option 2:
2.4L (2429cc) Inline-4 DOHC 16-valve, designated 'World Engine' (Code: ED3)
Engine Option 2 Hp:
147 hp @ 5200 rpm
Engine Option 2 Torque:
170 lb-ft @ 4000 rpm
Compression Ratio 4.0L:
8.8:1
Bore X Stroke 4.0L:
3.88 x 3.41 in (98.5 x 86.7 mm)
Fuel Delivery 4.0L:
Sequential Multi-Port Fuel Injection (MPI)
Fuel Type:
Unleaded Gasoline (87 octane recommended)
Ignition System:
Distributorless Ignition System (DIS) with coil-on-plug ignition (COP) for 4.0L; Coil-on-plug for 2.4L
Standard Transmission:
NSG 370 6-speed Manual Transmission (4.0L engine only)
Optional Transmission:
42RLE 4-speed Automatic Transmission (Both engines)
Transfer Case:
NV241 GII Command-Trac 2-speed part-time transfer case (standard)
Manual Transmission Fluid Spec Nsg370:
ATF+4 (Mopar) or equivalent SAE 75W-90 Synthetic
Automatic Transmission Fluid Spec 42Rle:
ATF+4 (Mopar) or equivalent
NHTSA Driver Side Frontal Impact:
4 stars (2004)
NHTSA Passenger Side Frontal Impact:
4 stars (2004)
NHTSA Side Impact Driver:
4 stars (2004)
NHTSA Side Impact Passenger:
4 stars (2004)
Active Safety Features:
Four-wheel disc brakes (standard on most trims), ABS (optional or standard depending on trim/market)
Passive Safety Features:
Front airbags, Three-point seat belts, Roll cage integrated into B-pillar and windshield frame
Infotainment System:
Base AM/FM radio with CD player. Optional premium sound systems were available. Auxiliary input ports were not standard.
Driver Assistance Features:
Limited driver assistance features typical for the era. Primarily focused on core vehicle dynamics and safety.
Connectivity Options:
No factory Bluetooth or USB connectivity. Aftermarket solutions are common for modern connectivity.
Oil Change Interval 4.0L:
Every 3,000 miles or 3 months, whichever comes first (severe duty); 7,500 miles or 6 months (normal duty) - check manual for specific conditions.
Transmission Fluid Interval Auto:
Inspect every 15,000 miles; change based on driving conditions, typically 30,000-60,000 miles.
Spark Plug Replacement 4.0L:
Approximately 100,000 miles (refer to manual for exact specification and gap)
Engine Oil Spec 4.0L:
SAE 10W-30 API SJ or higher
Engine Oil Capacity 4.0L:
5 quarts (4.7 liters) with filter
Coolant Spec:
Mopar OAT (Organic Additive Technology) or equivalent HOAT (Hybrid Organic Additive Technology) coolant, typically a 50/50 mix with distilled water.
Common Issues:
Oil filter housing leaks, valve cover gasket leaks, exhaust manifold cracks (especially on earlier 4.0Ls, though less common on 2004), transmission cooler line leaks, NP241 transfer case chain stretch, wheel hub bearing wear, interior water leaks around windshield and soft top.
Brand Heritage:
Jeep's heritage dates back to WWII with the Willys MB. The Wrangler nameplate, introduced in 1987, directly succeeded the CJ series, maintaining its off-road focus and iconic styling.
Tj Generation Evolution:
The TJ generation represented a significant shift from the YJ, returning to round headlights and introducing coil-spring suspension for improved ride comfort and articulation compared to the previous leaf-spring setup. For 2004, minor updates included potential updates to the PCM and OBD-II diagnostics.
Production Location:
Toledo, Ohio, USA
Off Road Capability:
Consistently recognized for its off-road prowess, frequently appearing on 'best of' lists for trail capability. The TJ platform is highly regarded by off-road enthusiasts.
Overall Reliability Perception:
Mixed. While the 4.0L engine is known for longevity, certain components and electronics can be prone to issues, making a comprehensive service manual crucial.
