🏷️ Basic Information

Make:

Jeep

Model:

Grand Cherokee

Model Code:

WG

Year:

1999

Internal Code:

WG

North American Code:

WJ

👋 Introduction

Market Position:

The Jeep Grand Cherokee WG (also known as the WJ in North America) was a significant evolution for Jeep, moving towards a more refined, unibody construction while retaining its legendary off-road capability. It competed directly with luxury SUVs like the Lexus RX and BMW X5, offering a blend of comfort, utility, and performance.

Competitive Analysis:

The WG generation aimed to broaden the Grand Cherokee's appeal beyond traditional off-road enthusiasts, incorporating a more car-like ride and premium interior appointments. This manual provides the critical technical data needed to maintain and repair this sophisticated vehicle, bridging the gap between traditional body-on-frame SUVs and the emerging luxury SUV segment.

Key Features:

This manual's key feature is its comprehensive nature, providing mechanics and owners with the authoritative information required for all service and repair tasks. It offers detailed diagrams, step-by-step procedures, and precise specifications crucial for accurate work.

📋 Manual Details

Coverage Areas:

Complete service, repair, and diagnostic information for the Jeep Grand Cherokee WG 1999 model.

Page Count:

Approximately 1500+ pages (typical for this era's comprehensive manuals; exact count depends on publisher).

Manual Type:

Service and Repair Workshop Manual

Language:

English

Format:

Digital (PDF), likely printable.

📖 Manual Coverage

Systems Covered:

Engine (including diagnostics, tuning, and overhaul), Drivetrain (4x4 systems, transfer cases), Transmission (automatic and manual), Brakes (ABS, hydraulic), Suspension (front and rear), Steering, Electrical System (including wiring diagrams, fuses, relays, lighting, starting/charging), HVAC, Fuel System, Cooling System, Exhaust System, Body (exterior and interior trim, doors, windows, seats), Body Control Modules (BCM), Powertrain Control Modules (PCM), and diagnostic trouble codes (DTCs).

Systems Covered Additional:

Airbag system diagnostics and deactivation procedures, anti-theft system (if equipped), keyless entry system, exterior lighting diagnostics, interior lighting and trim panel removal, seat adjustment mechanisms, power window and lock systems, sunroof operation and repair (if equipped).

Procedures Included:

Routine maintenance (oil changes, filter replacements, tune-ups), troubleshooting, diagnostic procedures, component removal and installation, repair procedures, rebuilding procedures, specifications for all major systems, torque specifications, electrical circuit testing, and component testing.

Procedures Included Additional:

Front and rear axle service, differential maintenance and repair, wheel bearing replacement, brake pad and rotor replacement, brake caliper overhaul, power steering pump and rack replacement, HVAC blower motor and evaporator core service, fuel pump and sender replacement, ignition system diagnostics and repair, emission control systems troubleshooting.

Technical Depth:

Comprehensive, suitable for professional mechanics and advanced DIY enthusiasts. Covers everything from basic maintenance to complete engine and transmission overhauls, including detailed diagnostic strategies and wiring diagrams.

📊 Manual Specifications

File Format:

PDF. High-resolution scans or digitally created documents with searchable text for easy navigation and keyword searching.

File Format Notes:

Searchable PDF allows for quick access to specific topics, part numbers, and diagnostic flowcharts, significantly improving repair efficiency.

Print Quality:

Excellent. Clear diagrams, legible text, and accurate representations of original factory documentation.

Binding Type:

Not applicable for digital format. If printed, typically a comb binding or professionally bound for durability.

Paper Type:

Not applicable for digital format. If printed, usually on heavy-duty paper suitable for workshop environments.

⚙️ Engine Specifications

Primary Engine:

4.0L Inline 6-Cylinder (PowerTech), naturally aspirated

Horsepower:

Approximately 190-195 hp @ 4600 rpm (exact figures may vary slightly by year and specific output).

Torque:

Approximately 235 lb-ft @ 3200 rpm (exact figures may vary slightly).

Fuel System:

Sequential Multi-Port Fuel Injection (MPI) with OBD-II diagnostics.

Engine Variant 2:

4.7L V8 Magnum, naturally aspirated

Horsepower Variant 2:

Approximately 220-230 hp @ 4700 rpm (exact figures may vary slightly).

Torque Variant 2:

Approximately 285-300 lb-ft @ 3200 rpm (exact figures may vary slightly).

Fuel System Variant 2:

Sequential Multi-Port Fuel Injection (MPI) with OBD-II diagnostics.

Engine Variant 3:

2.7L Turbo Diesel (VM Motori) - Primarily for export markets, not North America.

🔧 Transmission

Standard Transmission:

42RE 4-Speed Automatic Transmission (for 4.0L engine).

Optional Transmission:

45RFE 4-Speed Automatic Transmission (for 4.7L V8 engine, later revised to 545RFE 5-speed).

Features:

Both automatic transmissions feature electronic control for optimal performance and efficiency. The manual includes detailed diagnostic procedures, fluid capacities, and rebuilding instructions for these units.

Transfer Case:

NV231J (Command-Trac part-time 2-speed) or NV242J (Selec-Trac full-time 2-speed) depending on trim and options.

📐 Dimensions

Wheelbase:

116.7 inches (2964 mm)

Length:

185.5 inches (4712 mm)

Width:

73.3 inches (1862 mm)

Height:

66.1 inches (1679 mm)

Curb Weight:

Approximately 4,300 - 4,700 lbs (1950 - 2130 kg), depending on engine and drivetrain.

Cargo Volume Behind Rear Seat:

Approximately 37.7 cubic feet (1067 liters).

Cargo Volume With Rear Seat Folded:

Approximately 78.4 cubic feet (2220 liters).

🛡️ Safety Features

NHTSA Frontal Impact Driver:

4-star (1999 model year).

NHTSA Frontal Impact Passenger:

4-star (1999 model year).

Active Features:

Four-wheel Anti-lock Braking System (ABS), Traction Control System (TCS - optional on some trims).

Passive Features:

Front airbags (driver and passenger), available side-impact airbags (optional on some trims), three-point seat belts with pretensioners, side-impact door beams, crumple zones.

💡 Technology Features

Infotainment System:

Factory-installed AM/FM stereo with cassette and/or CD player. Optional Infinity Gold premium sound system with subwoofer. Manual covers basic functionality and troubleshooting.

Driver Assistance:

Cruise control. Optional ParkSense rear parking assist system (late models).

Connectivity:

Limited by modern standards. Primarily relies on analog signals and basic wiring harnesses. Manual provides comprehensive wiring diagrams essential for any aftermarket or diagnostic connectivity.

🔧 Maintenance

Oil Change Interval:

Every 3,000-5,000 miles (4,800-8,000 km) or 6 months, whichever comes first, depending on driving conditions (refer to manual for specific recommendations).

Air Filter Replacement:

Every 15,000-30,000 miles (24,000-48,000 km) or annually.

Spark Plug Replacement:

4.0L I6: Approx. 100,000 miles (160,000 km) with platinum-tipped plugs. 4.7L V8: Approx. 100,000 miles (160,000 km) with platinum-tipped plugs. Consult manual for exact type.

Engine Oil 4.0L:

SAE 10W-30 API SJ or SL certified (check manual for seasonal viscosity recommendations).

Engine Oil 4.7L:

SAE 5W-30 API SJ or SL certified (check manual for seasonal viscosity recommendations).

Transmission Fluid 42Re:

ATF+4 (MS-9602) or equivalent.

Transmission Fluid 45Rfe/545Rfe:

ATF+4 (MS-9602) or equivalent.

Coolant:

Chrysler HOAT (Hybrid Organic Acid Technology) type, a 50/50 mix of antifreeze and distilled water. Mopar P/N 05010855AA or equivalent.

Brake Fluid:

DOT 3.

Power Steering Fluid:

ATF+4 (MS-9602) or equivalent.

Transfer Case Fluid:

ATF+4 (MS-9602) or equivalent for NV231/NV242. Consult manual for specific transfer case fluid type if different.

Differential Fluid Front Rear:

API GL-5, SAE 75W-90 synthetic gear lubricant. Check manual for specific capacities and any limited-slip additive requirements.

Known Issues 1:

Cracked exhaust manifolds (especially on the 4.0L) due to thermal stress. The manual will cover diagnosis and replacement procedures.

Known Issues 2:

Leaking valve cover gaskets and oil pan gaskets. Torque specifications and sealing procedures are detailed in the manual.

Known Issues 3:

Water pump failures and coolant leaks, particularly around the thermostat housing and heater core connections. Manual provides coolant system flush and repair procedures.

Known Issues 4:

Chrysler's NV242 Selec-Trac transfer case can sometimes have issues with the vacuum actuator for 2WD/4WD engagement. The manual details diagnostic steps.

Known Issues 5:

PCM (Powertrain Control Module) failures, often manifesting as erratic engine performance or starting issues. Diagnostic procedures for the PCM and related sensors are included.

📚 Vehicle History

Brand Heritage:

Jeep has a long-standing reputation for robust off-road capability and utility, dating back to its World War II origins. The Grand Cherokee line, introduced in 1993, represented Jeep's entry into the upscale SUV market.

Model Evolution:

The WG/WJ generation, launched for the 1999 model year, marked a significant redesign from the ZJ predecessor. It adopted a unibody chassis for improved on-road refinement and safety, while retaining its four-wheel-drive prowess. This generation introduced more powerful V8 options and a more luxurious interior.

Production Years:

1999-2004 (WG/WJ generation).

Production Location:

Jefferson North Assembly Plant in Detroit, Michigan, USA.

🏆 Awards & Recognition

Recognitions:

The Jeep Grand Cherokee has consistently been recognized for its off-road capabilities. While specific awards for the 1999 WG generation may vary, it followed in the footsteps of its highly acclaimed predecessors and was a strong contender in the SUV segment during its production run.

Ratings:

Often rated highly for its towing capacity and off-road performance compared to competitors of the era.