🏷️ Basic Information

Make:

Infiniti

Model:

QX4

Model Years Covered:

2001, 2002, 2003

Vehicle Type:

Luxury Mid-size SUV

Platform Code:

R50 (Nissan Pathfinder platform)

👋 Introduction

Segment:

Luxury Mid-size SUV, often cross-shopped with Lexus RX, Acura MDX, and BMW X5 of the era.

Differentiation:

Offered a comfortable, refined ride with a standard V6 engine and available 4WD, leveraging Nissan's proven truck and SUV platform (shared with Pathfinder).

Engine Powertrain:

3.5L VQ35DE V6 engine and available ATTESA E-TS All-Mode 4WD system provided capable performance.

Luxury Appointments:

Premium interior materials, leather seating, Bose audio system, and available navigation were hallmarks of its luxury positioning.

📋 Manual Details

Primary Coverage:

Service and Repair

Secondary Coverage:

Maintenance, Troubleshooting, Diagnostics, Electrical Systems, Component Overhaul

Estimated Page Count:

Over 2000 pages (typical for comprehensive factory service manuals)

Type:

Factory Service Manual / Repair Manual

Language:

English

File Format:

PDF

Delivery Method:

Digital Download

📖 Manual Coverage

Engine Mechanical:

Engine assembly, cylinder head, valve train, pistons, connecting rods, crankshaft, oil pump, lubrication system, cooling system, timing system (chain/belt), engine diagnostics.

Engine Management:

ECM (Engine Control Module), fuel injection, ignition system, sensors (MAF, O2, crank, cam, knock), actuators, emissions control (EGR, PCV), OBD-II diagnostics.

Transmission Automatic:

RE4R01A (4-speed automatic): Hydraulic control, torque converter, planetary gear sets, valve body, solenoids, transmission control module (TCM), servicing, overhaul, diagnostics, fluid specifications.

Transmission Manual:

RM01A (5-speed manual): Gearbox assembly, clutch operation, linkages, servicing, overhaul, fluid specifications.

Drivetrain Transfer Case:

ATTESA E-TS (All-Mode Four-Wheel Drive): Operation, components, servicing, diagnostics, fluid specifications.

Drivetrain Axles Suspension:

Front and rear suspension components (struts, shocks, springs, control arms, bushings), steering knuckles, wheel bearings, CV joints, drive shafts, differential service (front/rear), hub units, alignment specifications.

Brakes:

Front and rear brake systems (disc brakes), ABS (Anti-lock Braking System), EBD (Electronic Brakeforce Distribution), hydraulic lines, calipers, rotors, pads, parking brake, bleeding procedures, specifications.

Steering:

Power steering system, steering rack, pump, hoses, fluid specifications, steering column components, adjustments.

Electrical Body:

Wiring diagrams, exterior and interior lighting, power windows, door locks, mirrors, seats, sunroof, wipers, washers, horn, keyless entry, alarm system, interior trim removal, body panel repair.

Electrical Chassis:

Instrument cluster, gauges, warning lights, audio system, navigation system (if equipped), cruise control, multiplex communication (CAN bus), fuse box locations, relay functions.

Safety Restraint:

Airbag system (SRS), seat belt pre-tensioners, occupant classification system, diagnostic procedures for SRS.

HVAC:

Air conditioning system (compressor, condenser, evaporator, refrigerant), heater core, blower motor, climate control unit, diagnostic procedures, refrigerant charging specifications.

Fuel System:

Fuel tank, fuel pump, fuel filter, fuel injectors, fuel lines, fuel pressure testing, evaporative emissions control (EVAP).

Emissions Control:

Catalytic converter, EGR valve, PCV system, oxygen sensors, secondary air injection system, emission control components and diagnostics.

Maintenance:

Scheduled maintenance items (oil changes, filter replacements, fluid checks/changes, spark plugs, belts, hoses, brake checks), lubrication points.

Diagnostics Troubleshooting:

Step-by-step troubleshooting flowcharts for common and uncommon issues, symptom-based diagnostics, DTC (Diagnostic Trouble Code) interpretation.

Repair Overhaul:

Complete disassembly and reassembly procedures for all major components and systems, torque specifications for critical fasteners, special tool requirements.

Electrical Diagnostics:

Detailed wiring diagrams, component testing procedures, voltage and resistance checks, signal tracing.

Special Tools:

Identification and use of specialized tools required for specific repairs (e.g., press tools, alignment equipment, diagnostic scanners).

Depth:

Comprehensive (from basic maintenance to complete engine and transmission rebuilds, including complex electrical diagnostics).

Detail Level:

Factory-level detail with substeps, notes, cautions, and warnings for critical procedures.

📊 Manual Specifications

Quality:

High-resolution PDF, searchable text, vector graphics for diagrams.

Printability:

Fully printable on standard printers, with options for individual page printing or sections.

Binding:

N/A (Digital Download - No physical binding)

Paper Type:

N/A (Digital Download - No physical paper)

Reader Requirement:

Adobe Acrobat Reader (or compatible PDF viewer)

Compression Requirement:

WinZip (or compatible file archiver for initial download)

⚙️ Engine Specifications

Engine Code:

VQ35DE

Engine Type:

3.5L (3498cc) DOHC 24-valve V6

Bore X Stroke:

95.5 mm x 81.4 mm

Compression Ratio:

9.7:1

Horsepower:

240 hp @ 6000 rpm (approx.)

Torque:

265 lb-ft @ 3200 rpm (approx.)

Fuel Delivery:

Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded gasoline, 87 octane recommended

Oil Capacity:

4.8 US quarts (4.5 liters) with filter change (VQ35DE)

Oil Specification:

API SG or higher, SAE 5W-30 or 10W-30 viscosity (refer to manual for exact seasonal recommendations)

🔧 Transmission

Type:

4-speed Automatic (RE4R01A)

Type:

5-speed Manual (RM01A)

4Wd System:

ATTESA E-TS (All-Mode Four-Wheel Drive) with electronic torque split control

Automatic Transmission Fluid:

Nissan Matic Fluid J or equivalent DEXRON III/MERCON

Manual Transmission Fluid:

API GL-4 or GL-5, SAE 75W-85 or 75W-90 viscosity

📐 Dimensions

Wheelbase:

111.2 inches (2824 mm)

Length:

189.1 inches (4803 mm)

Width:

71.7 inches (1821 mm)

Height:

65.7 inches (1669 mm)

Curb Weight:

4100 - 4300 lbs (approx., depending on drivetrain and options)

Cargo Volume:

37.1 cu ft (behind rear seats), 79.8 cu ft (with rear seats folded)

🛡️ Safety Features

NHTSA Frontal Crash:

5-Star Driver and Passenger (for relevant model years, check specific year ratings)

IIHS Side Impact:

'Acceptable' or 'Good' depending on year and specific test configurations (check IIHS archives).

ABS:

Standard Anti-lock Braking System

Traction Control:

Available Traction Control System (TCS) on some models.

Airbags:

Front dual-stage airbags, available front side-impact airbags.

Seat Belts:

3-point front and rear seat belts, front seat belt pre-tensioners.

💡 Technology Features

Audio System:

Available Bose premium audio system with CD player and AM/FM radio.

Navigation:

Optional factory DVD-based navigation system.

Cruise Control:

Standard cruise control.

Multiplex Communication:

Utilizes a multiplex wiring system (akin to early CAN bus) for various control modules, detailed in the electrical section.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 3 months for severe service, 7,500 miles or 6 months for normal service (refer to owner's manual for specific recommendations and oil type).

Engine Air Filter:

Inspect every 15,000 miles, replace as needed. Replace every 30,000 miles or sooner if dirty.

Spark Plugs:

Platinum-tipped plugs typically have a 100,000-mile replacement interval. Iridium plugs could have a longer interval. Consult manual for exact type and interval.

Transmission Fluid Change:

Every 30,000-60,000 miles, depending on driving conditions (severe vs. normal service). Check manual for specific recommendations.

Coolant Change:

Initial change at 30,000 miles or 2 years, then every 30,000 miles or 2 years thereafter. Use Nissan Genuine Super Long Life Coolant (Blue).

Brake Fluid:

DOT 3

Power Steering Fluid:

Nissan Genuine Power Steering Fluid or equivalent DEXRON II/III ATF.

Differential Fluid:

API GL-5, SAE 80W-90 gear oil for both front and rear differentials.

Intake Manifold Gasket Leaks:

Common on the VQ35DE engine, can cause coolant or vacuum leaks.

Transfer Case Actuator Failure:

The electronic actuator for the ATTESA E-TS system can fail, leading to 4WD system faults.

Oil Cooler Hose Leaks:

O-rings and hoses for the engine oil cooler can degrade and leak.

Cv Joint Boots:

Ruptured CV joint boots can lead to premature wear and failure of the joints.

Window Regulator Failure:

Power window regulators can wear out and fail.

📚 Vehicle History

Infiniti Launch:

Infiniti was launched by Nissan in 1989 as a luxury brand in North America.

Qx4 Introduction:

The QX4 was introduced for the 1997 model year, based on the second-generation Nissan Pathfinder (R50).

Model Updates 01-03:

The 2001 model year brought significant updates, including the new 3.5L VQ35DE engine and styling revisions. Later models in this range (2002-2003) saw minor equipment shuffling and refinements.

Manufacturing Location:

Japan (primarily)

🏆 Awards & Recognition

Jd Power Initial Quality:

Infiniti models frequently ranked well in J.D. Power Initial Quality studies during this period, reflecting Nissan's quality improvements.

Ward Auto Engines:

The VQ35DE engine was a consistent recipient of Ward's 10 Best Engines awards.