Positioning:
The 1991 Infiniti Q45 was positioned as a luxury flagship sedan, directly competing with established European and American luxury marques, emphasizing performance and a unique, bold design.
Competitors:
Mercedes-Benz S-Class, BMW 7 Series, Lexus LS 400, Cadillac DeVille, Lincoln Town Car.
Features:
Powerful V8 engine, advanced suspension (multi-link front and rear), luxurious interior appointments, distinctive exterior styling.
Driving Dynamics:
Renowned for its refined ride and confident handling, a departure from many traditional American luxury cars of the era.
Coverage:
Comprehensive service and repair information for the 1991 Infiniti Q45.
Page Count Estimate:
Likely extensive, typical for OE service manuals (e.g., 1000+ pages, not specified in product info).
Type:
Official Service and Repair Manual Software
Licensing:
Officially licensed, derived from OE (Original Equipment) materials.
Format:
Online software/web-based access
Systems:
Engine, Drivetrain, Suspension, Steering, Brakes, Electrical Systems, HVAC, Body, Chassis, Fuel System, Exhaust System, Cooling System, Lubrication System, Ignition System, Emission Control System.
Electrical Systems:
Comprehensive coverage including engine control, lighting, power accessories, dashboard instrumentation, audio system, HVAC controls, and ABS system wiring diagrams.
Drivetrain:
Rear-wheel drive system, driveshafts, differential, axles.
Brakes:
Front and rear disc brakes, hydraulic system, ABS component details.
Steering:
Power assisted rack and pinion steering, steering column components, tie rods, linkages.
HVAC:
Air conditioning system (refrigerant type, components, service), heater system, climate control unit operation and repair.
Procedures:
Routine maintenance, diagnostics, troubleshooting, component replacement, repair procedures, assembly/disassembly, electrical wiring diagrams, torque specifications, special tools, and procedures.
Troubleshooting:
Detailed diagnostic flowcharts, symptom-based troubleshooting guides, and component testing procedures.
Maintenance:
Scheduled maintenance intervals, fluid checks and changes, filter replacements, inspection points.
Repair:
Detailed step-by-step repair instructions for all major and minor components.
Depth:
Factory-level detail suitable for professional technicians and advanced DIYers, covering everything from basic fluid changes to complete engine and transmission rebuilds.
Diagnostics:
Includes information on the OBD-I diagnostic system (or Nissan's proprietary diagnostic port) and codes relevant to the 1991 model year.
Format:
Web-browser accessible software, likely HTML5/JavaScript based.
Accessibility:
Accessible on PC, laptop, smartphone, or tablet with an internet connection and web browser.
Print Quality:
N/A (Digital Format), but derived from OE materials implying high-quality technical illustrations and diagrams.
Binding:
N/A (Digital Format)
Paper Type:
N/A (Digital Format)
Engine Type:
4.5L DOHC 32-valve V8
Horsepower:
278 hp @ 6000 rpm (approximate)
Torque:
297 lb-ft @ 4000 rpm (approximate)
Fuel Delivery:
Electronic Fuel Injection (EFI) with multi-port injection.
Recommended Octane:
Premium Unleaded Gasoline (91 Octane or higher)
Coolant Capacity:
Approximately 10.6 quarts (10.0 liters) - refer to manual for exact specification.
Oil Capacity:
Approximately 5.3 quarts (5.0 liters) with filter change - refer to manual for exact specification.
Recommended Oil Viscosity:
5W-30 or 10W-30 API SG/SH - refer to manual for exact specification.
Engine Block Material:
Aluminum Alloy
Cylinder Head Material:
Aluminum Alloy
Audio System:
Premium Bose audio system was often standard or optional, featuring CD player and cassette deck.
Climate Control:
Automatic climate control with digital display.
Cruise Control:
Standard electronic cruise control.
Suspension Features:
Active Suspension System (optional on some models/trims) for enhanced ride and handling control. This manual would detail its operation and service.
Connectivity Features:
Limited by 1991 standards; primarily focused on internal vehicle systems and premium audio.
Oil Change Interval:
Every 3,750 miles or 6 months (refer to manual for specific conditions and extended intervals).
Spark Plug Replacement:
Approximately 60,000 miles (refer to manual for specific plug type and torque).
Timing Belt Replacement:
The VH45DE engine uses a timing chain, not a belt, eliminating this regular replacement interval.
Brake Fluid:
DOT 3 or DOT 4 (refer to manual for exact specification and part number).
Power Steering Fluid:
Nissan/Infiniti Genuine Power Steering Fluid or equivalent (refer to manual for exact specification and part number).
Common Problems:
Potential for aging electronic components, HVAC system issues (blend doors, blower motors), valve cover gasket leaks, and some suspension wear due to age and mileage. The manual would detail diagnostic procedures for these.
Oil Filter Example:
Nissan/Infiniti Part Number 15208-45300 or equivalent aftermarket (e.g., Wix 51042, Purolator L30001).
Air Filter Example:
Nissan/Infiniti Part Number 16546-45300 or equivalent aftermarket.
