🏷️ Basic Information

Make:

Pontiac

Model:

Grand Prix

Year:

1990

Chassis Code:

W-Body

👋 Introduction

Market Position:

The 1990 Pontiac Grand Prix was a popular mid-size personal luxury coupe/sedan, known for its sporty styling and comfortable interior. This manual targets owners and independent repair shops seeking comprehensive, accurate repair data.

Competitors:

Competed with vehicles like the Ford Taurus, Chevrolet Lumina, and Chrysler LeBaron coupe.

Key Features Of Manual:

Vehicle-specific, factory-issued information, detailed step-by-step instructions, extensive illustrations and diagrams, wiring schematics, diagnostic procedures, and complete A-Z repair coverage.

Value Proposition:

This manual is the definitive resource for maintaining, servicing, diagnosing, and repairing a 1990 Pontiac Grand Prix, empowering owners and technicians with factory-level knowledge to perform any repair correctly and efficiently.

📋 Manual Details

Coverage:

All models and repairs A-Z

Page Count:

Not Specified (assumed comprehensive for a full service manual)

Manual Type:

Factory Service and Repair Manual

Language:

English

Format:

Digital PDF

Zoom And Print:

Images can be blown up and printed in enlarged copies.

Convenience:

Single PDF file, no need to flip through multiple books, print only needed pages.

Download Speed:

Speed Download

📖 Manual Coverage

Engine:

Yes (including maintenance, diagnostics, repair)

Control System:

Yes (ECU, sensors, actuators)

Mechanical:

Yes (detailed mechanical components and procedures)

Fuel System:

Yes (including service specifications)

Emission Control:

Yes

Intake Exhaust Cooling:

Yes

Lube:

Yes (lubrication specifications and procedures)

Ignition Starting Charging:

Yes

Automatic Transmission:

Yes (clutch, transmission operation, repair)

Manual Transmission:

Yes

Transfer Propeller Shaft:

Yes

Drive Shaft:

Yes

Differential:

Yes

Axle Suspension:

Yes

Tire Wheel:

Yes

Brake Control:

Yes

Brake:

Yes

Parking Brake:

Yes

Steering Column:

Yes

Power Steering:

Yes

Air Conditioning:

Yes

Supplemental Restraint System:

Yes (SRS)

Seat Belt:

Yes

Engine Immobilizer:

Yes

Cruise Control:

Yes

Wiper Washer:

Yes

Door Lock:

Yes

Meter Audio Visual:

Yes

Horn:

Yes

Windshield Glass Mirror:

Yes

Instrument Panel:

Yes

Seat:

Yes

Engine Hood Door:

Yes

Exterior Interior:

Yes

Electrical:

Yes (comprehensive coverage including schematics)

Multiplex Can Communication:

Yes (likely covering early multiplexing systems for this era)

Procedures:

Maintenance, Servicing, Diagnosis, Repair, Troubleshooting, Component Replacement, Adjustment, Calibration

Depth:

Factory-level detail, step-by-step instructions, diagrams, illustrations, wiring schematics, specifications

Wiring Schematics Coverage:

Complete and detailed wiring schematics are included for all electrical systems.

Diagnostic Procedures:

Detailed diagnostic procedures for common faults and system malfunctions are provided, often including symptom-to-cause charts.

Body And Interior Coverage:

Includes procedures for body panel alignment, door mechanisms, interior trim removal and installation, glass replacement, and upholstery repair.

📊 Manual Specifications

File Format:

PDF

Printability:

Yes, all pages printable

Binding Type:

N/A (Digital PDF)

Paper Type:

N/A (Digital PDF)

Compatibility:

Windows (Vista 32/64, XP, ME, 98, NT, 2000) and Mac. Requires Adobe PDF Reader and Winzip (free).

File Type:

PDF document

⚙️ Engine Specifications

Engine Options 1990:

3.1L V6 (RPO LHO), 3.4L V6 (RPO LQ1 '3.4 SFI Twin-Cam' - available mid-year or in certain trims)

Engine Power 3 1L:

Approx. 135 hp @ 4400 rpm (varied slightly by year/tune)

Engine Torque 3 1L:

Approx. 180 lb-ft @ 3200 rpm (varied slightly by year/tune)

Fuel System Type:

Fuel Injection (Multi-Port Fuel Injection - MPFI)

3 1L V6 Engine Code:

RPO LHO (2.8L for early W-body, 3.1L for later W-body, specific to 1990 Grand Prix)

3 4L V6 Engine Code:

RPO LQ1 (3.4 DOHC V6, often referred to as 'Twin-Cam')

Cooling System Details:

Covers radiator, water pump, thermostat, hoses, and coolant specifications and replacement procedures.

🔧 Transmission

Transmission Options:

Typically 3-speed Automatic (THM-3T40) or 4-speed Automatic (4T60-E) depending on engine and trim.

Optional Transmission:

Manual transmission was generally not offered on US-market Grand Prix models in 1990, emphasis was on automatics.

Transmission Features:

Features covered include torque converter operation, valve body diagnostics, electronic control (for 4T60-E), fluid service, and rebuild procedures.

📐 Dimensions

Wheelbase:

Approx. 107.7 inches

Curb Weight:

Approx. 3100-3300 lbs (varies by model and options)

🛡️ Safety Features

Safety Ratings Historical:

As a 1990 model, official crash test ratings (like NHTSA's star ratings) were less standardized. However, it featured a robust body structure for its era.

Active Safety Features:

Front-wheel drive, Anti-lock Braking System (ABS) available as an option on certain models.

Passive Safety Features:

Seat belts, padded interior surfaces, energy-absorbing steering column. Supplemental Restraint System (SRS) - airbags were optional or standard on higher trims/late models of this generation, but specific availability for 1990 Grand Prix should be verified against trim level.

Seat Belt Type:

Three-point retractable seat belts for front occupants, lap belts for rear occupants. Manual details adjustment and repair.

💡 Technology Features

Infotainment System:

Standard AM/FM radio, cassette player. Optional premium sound systems, CD players were becoming available. Manual covers system diagnostics and repair.

Driver Assistance Features:

Cruise control was a common convenience feature. ABS was an option. No advanced driver-assistance systems (ADAS) like lane keeping or adaptive cruise control.

Connectivity Features:

Basic connectivity via antenna and wiring for radio. No Bluetooth or Wi-Fi. Manual details all electrical connections.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or 3-6 months, depending on driving conditions. Consult the manual for precise recommendations based on oil type and usage.

Tune Up Interval:

Spark plugs and filters generally recommended at 30,000-60,000 mile intervals, but consult manual for specific component life.

Engine Oil Spec:

Likely API SG or SH certified, SAE 5W-30 or 10W-30 depending on climate. Manual will provide exact specifications and capacities.

Transmission Fluid Spec:

Dexron-II or Dexron-III automatic transmission fluid (ATF). Capacity typically 4-5 quarts for a fluid change. Manual will specify exact type and capacity for service and overhaul.

Common Issues 1990 Gp:

Potential issues include: intake manifold gasket leaks (3.1L V6), coolant leaks, electronic control module (ECM) issues, power window motor failures, and wear on suspension components. Manual provides diagnostic procedures for these and more.

Torque Specifications Availability:

Comprehensive torque specifications for critical fasteners (engine, chassis, brakes, etc.) are included.

Oil Filter Part Number:

Part numbers for filters (oil, air, fuel) are typically listed, but vary by manufacturer. The manual will provide OEM or equivalent part numbers.

📚 Vehicle History

Pontiac Heritage:

Pontiac was known for its performance-oriented image and sporty styling within General Motors. The Grand Prix has been a cornerstone of their lineup since the 1960s.

W Body Generation:

The 1990 Grand Prix is part of the third generation of the W-body platform, which debuted in 1988. This generation offered more aerodynamic styling and improved performance compared to its predecessors.

Production Years:

The W-body Grand Prix was produced from 1988 to 1996 for this generation.