🏷️ Basic Information

Make:

GMC

Model:

Jimmy

Year:

1990

Generation Designation:

Second Generation (GMT400)

Platform Code:

GMT400

👋 Introduction

Target Audience:

DIY enthusiasts, independent repair shops, and GMC Jimmy owners seeking factory-accurate repair information.

Differentiation:

Emphasizes vehicle-specific information identical to dealership technician manuals, differentiating from generic repair guides.

Completeness:

Offers comprehensive, step-by-step instructions, diagrams, illustrations, and schematics for complete vehicle repair.

Digital Convenience:

Provided in a user-friendly PDF format, eliminating the need to handle greasy physical manuals and allowing selective printing.

📋 Manual Details

General Coverage:

All Models & All Repairs A-Z

Specific Systems:

Engine, Control System, Mechanical, Fuel, Emission Control, Intake/Exhaust/Cooling, Lube, Ignition, Starting/Charging, Transmission (Auto/Manual), Transfer Case, Drivetrain, Suspension, Brakes, Steering, Climate Control, Supplemental Restraint System, Seat Belts, Immobilizer, Cruise Control, Wipers/Washers, Door Locks, Instruments, Audio/Visual, Horn, Glass, Interior/Exterior, Electrical, Multiplex/CAN Communication

Page Count Estimate:

Detailed as per factory specifications, often exceeding 1000 pages for comprehensive coverage.

Type:

Factory Service Manual / Repair Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine Management:

Detailed diagnostics, repair, and specifications for fuel injection, ignition, emissions control, and engine mechanical components.

Powertrain:

Comprehensive coverage of automatic and manual transmissions, transfer cases, drive shafts, axles, and differentials.

Chassis Suspension Brakes Steering:

In-depth information on suspension components, brake system hydraulics and diagnostics, power steering systems, and steering column assemblies.

Electrical Electronics:

Extensive wiring schematics, component testing, diagnostics for lighting, instruments, comfort systems, and multiplex communication.

Routine Maintenance:

Oil changes, fluid checks and replacements, filter replacements, lubrication, tire rotation, and general inspection procedures.

Diagnostic Troubleshooting:

Step-by-step diagnostic flowcharts and symptom-based troubleshooting for all major vehicle systems.

Repair Rebuild:

Complete instructions for component removal, disassembly, repair, reassembly, and installation for all major systems.

Component Replacement:

Detailed guides for replacing common wear items and major components like engines, transmissions, alternators, starters, etc.

Diagnostic Capabilities:

Advanced diagnostic procedures leveraging factory-level understanding of system operation and fault detection.

Rebuilding Specifications:

Precision specifications for engine internal clearances, transmission component tolerances, and bearing preloads for complete rebuilds.

Electrical Schematics:

High-quality, printable wiring diagrams with component identification and circuit tracing for all electrical systems.

Diagnostic Tools:

Implicitly covers the use of factory scan tools and specialized diagnostic equipment where applicable for the 1990 model year.

📊 Manual Specifications

File Type:

PDF

Compatibility:

Windows (Vista32/64, XP, ME, 98, NT, 2000) and Mac OS compatible.

Searchability:

Likely includes searchable text for efficient information retrieval.

Printable:

Yes, all pages are printable.

Image Zoom:

Ability to blow up images for enlarged printing.

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format, user determines print media)

Delivery Method:

Speed Download

Software Requirements:

Adobe PDF Reader and Winzip (free online).

⚙️ Engine Specifications

Engine Options:

The 1990 GMC Jimmy, built on the GMT400 platform, was commonly equipped with General Motors' robust V6 and V8 engines. Likely options include the 4.3L V6 (LV3 or similar) and potentially larger V8s depending on trim and configuration.

Horsepower Torque Range:

Performance figures varied by specific engine and configuration. For example, the 4.3L V6 typically produced around 160-165 horsepower and 230-235 lb-ft of torque, while V8 options would offer more.

Injection Type:

The 1990 model year typically featured Electronic Fuel Injection (EFI) or Central Sequential Fuel Injection (CSFI) systems, replacing older carburetor technology.

Identifying Engines:

The manual would provide specific engine codes for accurate identification and component sourcing.

🔧 Transmission

Standard Transmission:

While manual transmissions were available, automatic transmissions were far more common in the GMC Jimmy. The manual would detail both.

Optional Transmission:

Likely options include the 4-speed automatic 700R4 (or its successor, the 4L60) and potentially a manual transmission like the Getrag 5-speed if offered in specific configurations.

Transmission Features:

Coverage includes torque converter operation, valve body diagnostics, clutch pack service, and electronic control unit (ECU) integration for automatic transmissions.

📐 Dimensions

Body Styles:

The 1990 GMC Jimmy was primarily offered as a two-door or four-door sport utility vehicle (SUV).

Wheelbase Range:

Wheelbase varied depending on the two-door or four-door configuration, with typical values around 106.4 inches (2-door) and 111.5 inches (4-door).

Curb Weight Range:

Curb weight varied significantly based on engine, drivetrain, and options, generally ranging from approximately 4,000 to 5,000 lbs.

🛡️ Safety Features

Crash Test Results:

Specific crash test ratings for the 1990 model are not readily available in a standardized format as they are today, but the manual would cover safety systems.

Braking System:

Covers Anti-lock Braking System (ABS) for models equipped with it, including hydraulic modulator and sensor diagnostics.

Seat Belts:

Detailed procedures for seat belt inspection, adjustment, and replacement, including retractors and anchor points.

Supplemental Restraint System:

Coverage for early airbag systems, including component testing, diagnostic codes, and safety precautions during service.

💡 Technology Features

Audio Systems:

Coverage for factory radio/cassette systems, speaker replacement, and antenna systems. Upgrades to modern head units would require separate research but the manual covers wiring basics.

Cruise Control:

Detailed troubleshooting and repair procedures for the cruise control system, including actuator, vacuum lines, and control module.

Multiplex Communication:

While limited by 1990 standards, the manual would cover the early multiplexed communication systems used for certain functions, providing basic wiring and diagnostic insights.

🔧 Maintenance

Oil Change Interval:

Typically recommended every 3,000-7,500 miles or 3-6 months, depending on driving conditions and oil type. The manual will provide exact intervals.

Tune Up Interval:

Spark plug replacement and related services were often recommended at intervals between 30,000 and 100,000 miles, depending on spark plug technology used (e.g., standard, platinum).

Engine Oil Viscosity:

Commonly specified viscosities include 5W-30 and 10W-30, with specific recommendations based on ambient temperature. Dexos or equivalent API-certified oils are recommended.

Transmission Fluid Type:

For the common 4L60 automatic transmission, Dexron-III (or equivalent) automatic transmission fluid (ATF) is typically specified. Manual transmissions and transfer cases would have their own specific fluid requirements.

Coolant Type:

A mixture of ethylene glycol antifreeze and distilled water is standard. Specific GM coolant specifications would be detailed in the manual.

Common Wear Items:

Potential common issues for this era include water pump leaks, alternator failures, exhaust manifold leaks, and issues with the electronic control module (ECM) or sensors.

Drivetrain Wear:

Front and rear axle seals, U-joints on the driveshaft, and transfer case seals can be prone to wear and leaks over time.

📚 Vehicle History

Gmc Legacy:

GMC (General Motors Truck Company) has a long history of producing robust trucks and SUVs, known for their truck-like capabilities and durability.

Gmt400 Platform:

The 1990 Jimmy was part of the second generation (GMT400) platform, a significant redesign for GM's truck and SUV line, introducing more modern styling and engineering.

Manufacturing Locations:

GMT400 vehicles were produced in various General Motors assembly plants across North America.

🏆 Awards & Recognition

Truck Of The Year:

While the Jimmy itself may not have a specific 'Award of the Year' for 1990, the GMT400 platform was well-regarded for its advancements in truck and SUV design.

Consumer Ratings:

Consumer satisfaction and reliability ratings for this era would vary, but the manual's comprehensive nature helps owners maintain and extend the vehicle's lifespan.

Manual Quality:

This manual is described as 'Factory Highly Detailed,' implying it meets rigorous OEM documentation standards.