🏷️ Basic Information

Make:

GMC

Model:

Sonoma

Year:

1999

Platform:

GMT355 (Second Generation)

👋 Introduction

Target Audience:

DIY enthusiasts, independent repair shops, and dealerships seeking accurate, vehicle-specific repair information.

Truck Segment:

Compact Pickup Truck segment.

Differentiation:

Provides exact factory-level information used by dealership technicians, unlike generic repair guides. Offers comprehensive, vehicle-specific data for ease of repair.

Format Advantage:

Single, easy-to-use PDF manual. No need to flip through multiple books. Printable pages for workshop convenience.

Diagnostic Capability:

Empowers users to perform complex diagnostics typically requiring dealership tools, by providing detailed procedures and expected readings.

📋 Manual Details

Primary Coverage:

Service, Maintenance, Diagnosis, and Repair

Model Variants Covered:

All models, including different cab configurations (regular cab, extended cab), bed lengths, and driveline options (2WD, 4WD).

Estimated Pages:

Varies by specific manual publisher, but typically 1000+ pages for comprehensive factory service manuals.

Type:

Factory Service Manual (FSM) / Repair Manual

Language:

English

Digital Format:

PDF

Operating Systems:

Windows Vista (32/64-bit), XP, ME, 98, NT, 2000, and macOS compatible.

Software Requirements:

Adobe PDF Reader and WinZip (both free online).

Zoom Capability:

Allows users to zoom into illustrations and schematics for a closer, more detailed view.

📖 Manual Coverage

Powertrain:

Engine Mechanical, Engine Control System, Fuel System, Emission Control, Cooling System, Lubrication System, Ignition System, Starting & Charging System, Automatic Transmission, Manual Transmission, Transfer Case (if applicable), Drive Shaft, Differential, Axles.

Chassis:

Suspension System, Steering System (including Power Steering), Brake System (including Parking Brake), Wheels & Tires.

Body And Electrical:

Body & Interior (doors, windows, seats, instrument panel, exterior trim), HVAC (Air Conditioning), Supplemental Restraint System (SRS/Airbags), Seat Belts, Cruise Control, Wiper & Washer System, Door Locks, Meter/Audio/Visual Systems, Horn, Windshield/Glass/Mirrors, Electrical System (including wiring schematics, multiplex communication/CAN bus for applicable components).

Interior Systems:

Covers instrument panel, seats, interior trim, door panels, headliner, and all associated components.

Exterior Systems:

Includes front and rear bumpers, fenders, hood, doors, tailgate, exterior lighting, and mirrors.

Maintenance:

Scheduled maintenance, fluid checks and changes, filter replacements, lubrication points.

Diagnostics:

Troubleshooting guides, diagnostic trouble codes (DTCs), component testing procedures, wiring diagram interpretation.

Repair:

Step-by-step repair instructions for all major mechanical and electrical components, component removal and installation, torque specifications, alignment procedures.

Engine Rebuild:

Detailed procedures for engine disassembly, inspection, repair, and reassembly, including specifications for all internal components.

Transmission Service:

Comprehensive guide for both automatic and manual transmission service, including removal, overhaul, fluid changes, and diagnostics.

Suspension And Steering:

Instructions for servicing and replacing suspension components (shocks, struts, control arms, ball joints) and steering system parts (tie rods, power steering pump, rack and pinion).

Brake System Repair:

Detailed procedures for brake pad replacement, rotor service, caliper repair, brake fluid flushing, and ABS system diagnostics.

Electrical Troubleshooting:

Extensive wiring diagrams and diagnostic flowcharts for all electrical systems, enabling efficient troubleshooting of lighting, power windows, starter/charging, and sensors.

Component Replacement:

Detailed guides for replacing all wear items and components, from spark plugs and belts to major assemblies like engines and transmissions.

Emission Control Service:

Information on emission control systems, catalytic converters, oxygen sensors, and related diagnostic procedures.

Depth:

Factory-level, A-Z coverage for all repairs and maintenance. Includes detailed diagrams, illustrations, and wiring schematics.

📊 Manual Specifications

File Type:

PDF

Searchability:

PDF format allows for text searching within the document, expediting the location of specific topics or procedures.

Printability:

All pages are printable. Users can print specific pages or diagrams as needed. Images can be enlarged for detailed viewing before printing.

Binding:

Digital (PDF) - no physical binding. Eliminates issues of greasy or torn paper manuals.

Paper Medium:

N/A (Digital)

⚙️ Engine Specifications

Engine Options:

2.2L 4-Cylinder (L42), 4.3L V6 (LV3)

2.2L I4 Horsepower:

Approximately 118 hp @ 5200 rpm

4.3L V6 Horsepower:

Approximately 150-190 hp @ 4400-4800 rpm (depending on specific configuration)

Fuel Delivery:

Fuel Injection (Multi-Port Fuel Injection - MPFI)

Engine Management:

ECU (Engine Control Unit) based management system.

Engine Code 2 2L:

L42

Engine Code 4 3L V6:

LV3

🔧 Transmission

Standard Transmission:

5-Speed Manual Transmission (NV1500)

Optional Transmission:

4-Speed Automatic Transmission (4L60-E)

Transfer Case Options:

Available for 4WD models (e.g., NP136 or NP236 electronic shift transfer case).

Automatic:

4L60-E

Manual:

NV1500 (5-speed)

📐 Dimensions

Wheelbase Options:

Short Wheelbase (SWB) and Long Wheelbase (LWB) configurations available.

Curb Weight Range:

Approx. 3,100 - 3,800 lbs (depending on configuration).

Gross Vehicle Weight Rating Gvwr:

Varies by configuration, consult manual or vehicle VIN for specific GVWR.

Available Configurations:

Regular Cab, Extended Cab, Fleetside (standard bed), Stepside (narrower bed).

🛡️ Safety Features

NHTSA Ratings:

Information varies by specific crash tests conducted for the model year. Generally offered standard driver and passenger airbags.

Side Impact Ratings:

Information not readily available for this specific year, manual provides diagnostic and repair data for safety systems.

ABS:

Anti-lock Braking System (ABS) available, often standard on higher trims or optional.

Airbags:

Driver and Passenger Frontal Airbags.

💡 Technology Features

Audio System:

Factory radio with AM/FM, cassette, and optional CD player. Speaker configurations vary by trim level.

Cruise Control:

Cruise control was an available option on many models and is covered within the manual's electrical and interior sections.

Multiplex Communication:

The manual covers electrical systems including multiplex/CAN communication, which managed various vehicle functions and diagnostics.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-7,500 miles or 6-12 months, depending on oil type and driving conditions (refer to manual for exact specifications).

Engine Oil:

Refer to manual for specific viscosity grade (e.g., 5W-30 or 10W-30) and API service classification.

Transmission Fluid Auto:

Dexron-III (or equivalent) for 4L60-E automatic transmission.

Transmission Fluid Manual:

GL-4 or GL-5 gear oil (specific viscosity to be confirmed in manual).

Coolant:

Ethylene Glycol based, typically a 50/50 mix with deionized water. Specific type (e.g., traditional green or extended life) to be confirmed in manual.

Brake Fluid:

DOT 3

Power Steering Fluid:

Dexron-III (or equivalent).

Common Sonoma Issues:

Potential for rear main seal leaks (especially on V6), ball joint wear, brake component wear, and occasional electrical gremlins. The manual will guide on diagnosing and repairing these.

📚 Vehicle History

Gm Truck Lineage:

The Sonoma is part of GMC's long-standing tradition of offering compact and mid-size pickup trucks, closely related to the Chevrolet S-10.

Generation:

This manual covers the second generation of the GMC Sonoma, which debuted in late 1997 for the 1998 model year, running through 2004.

Manufacturing Location:

Assembly plants in North America, including Shreveport, Louisiana, and Moraine, Ohio.