🏷️ Basic Information

Make:

GMC

Model:

Sonoma

Year:

1999

Body Style:

Compact Pickup Truck

Platform Code:

GMT355 (second generation)

👋 Introduction

Positioning:

The 1999 GMC Sonoma was a compact pickup truck offering a balance of utility, maneuverability, and available V6 power, positioned as a capable workhorse and daily driver for individuals and small businesses, competing with vehicles like the Ford Ranger and Toyota Tacoma.

Competitors:

Ford Ranger, Chevrolet S-10 (platform sibling), Toyota Tacoma, Nissan Frontier, Mazda B-Series.

Features:

Available in Regular Cab, Extended Cab, and Access Cab configurations; choice of 2WD and 4WD; selection of gasoline engines including a 2.2L 4-cylinder and powerful V6 options; durable construction for work and recreational use.

📋 Manual Details

Primary Coverage:

All aspects of 1999 GMC Sonoma operation, maintenance, and features.

Geographic Coverage:

Primarily U.S. market (reporting safety defects section explicitly U.S. only).

Estimated Page Count:

150-250 (typical for owner's manuals of this era; exact count not specified)

Type:

Owner's Manual

Language:

English

Digital Format:

PDF Download

📖 Manual Coverage

Instrument Cluster:

Gauges, warning lights, indicators (speedometer, tachometer, fuel, temperature, oil pressure, battery voltage, check engine, ABS, airbag).

Entertainment Systems:

Radio operation (AM/FM, cassette, CD options), speaker controls, antenna operation.

Climate Controls:

HVAC system operation (heating, ventilation, air conditioning), fan speed, temperature control, recirculation, air direction.

Lights:

Headlights (low/high beam), parking lights, taillights, brake lights, turn signals, hazard lights, interior lighting, fog lamps (if equipped).

Driver Controls:

Steering wheel functions, ignition system (key positions), wipers and washers (front), turn signal stalk, cruise control (if equipped).

Locks And Security:

Door locks (manual, power), keyless entry system (if equipped), ignition lock, anti-theft system (if equipped).

Seating And Safety Restraints:

Seat adjustment, seat belts (lap and shoulder), airbag system (driver, passenger), child seat LATCH system (if applicable).

Driving:

Starting the engine, shifting gears (automatic/manual), braking, parking, towing information, off-road driving considerations.

Customer Assistance:

Contact information for GMC customer service, warranty information, dealer services.

Reporting Safety Defects:

Procedure for reporting safety-related defects to NHTSA in the U.S.

Cleaning:

Exterior and interior cleaning recommendations, care for upholstery and trim.

Maintenance And Specifications:

General maintenance procedures and technical specifications.

Engine Compartment:

Identification of engine components, fluid level checks, basic checks.

Engine Oil:

Oil type, viscosity, capacity, and checking procedure.

Battery:

Battery type, maintenance, jump starting procedures.

Fuel Information:

Recommended fuel type, octane rating, refueling procedures.

Air Filter:

Location and replacement information for engine air filter(s).

Part Numbers:

Key part numbers for common maintenance items (e.g., filters, spark plugs - specific numbers likely not in owner's manual, but replacement intervals often are).

Refill Capacities:

Fluid capacities for engine oil, coolant, transmission fluid, brake fluid, washer fluid.

Lubricant Specifications:

Recommended types and grades for various lubrication points (e.g., chassis grease, transmission fluid).

Accessories:

Information on factory-installed accessories and their operation.

Routine Maintenance:

Checking fluid levels, tire pressure, wiper blade inspection, basic checks.

Troubleshooting:

Basic troubleshooting guidance for common vehicle issues (e.g., starting problems, warning lights).

Emergency Procedures:

Jump starting, tire changing, safe roadside procedures.

Safety Information:

Detailed information on airbags, seat belts, child restraints, and safe driving practices.

Depth:

Owner-level maintenance and operation. Focuses on user understanding and basic upkeep, not in-depth repair diagnostics or component-level rebuilding.

📊 Manual Specifications

Format:

PDF

Readability:

Requires a PDF reader (e.g., Adobe Acrobat Reader, Foxit Reader).

Quality:

Digital reproduction of original factory manual; quality dependent on original scan but generally expected to be clear for text and diagrams.

Binding:

N/A (Digital Download - No physical binding)

Paper Type:

N/A (Digital Download - No physical paper)

⚙️ Engine Specifications

Engine 1:

2.2L OHV 4-Cylinder (RPO: L43)

Engine 1 Displacement:

2198 cc (134 cu in)

Engine 1 Horsepower:

118 hp @ 4800 rpm (approx.)

Engine 1 Torque:

130 lb-ft @ 2800 rpm (approx.)

Engine 2:

4.3L OHV V6 (RPO: L35)

Engine 2 Displacement:

4300 cc (262 cu in)

Engine 2 Horsepower:

190 hp @ 4400 rpm (approx.)

Engine 2 Torque:

250 lb-ft @ 2800 rpm (approx.)

Fuel Delivery:

Multi-port Fuel Injection (MPFI)

Fuel Requirement:

Unleaded gasoline, 87 octane minimum recommended.

🔧 Transmission

Transmission 4 Cyl:

5-speed manual transmission

Transmission V6:

4-speed automatic transmission (e.g., 4L60-E)

Drive Type:

Rear-Wheel Drive (RWD) or Four-Wheel Drive (4WD)

📐 Dimensions

Wheelbase Short Bed:

108.3 inches (2751 mm)

Wheelbase Long Bed:

111.5 inches (2832 mm)

Bed Length Standard:

72.9 inches (1852 mm)

Bed Length Long:

76.5 inches (1943 mm)

Curb Weight Range:

Approximately 3,000 - 3,700 lbs (1361 - 1678 kg), varying by configuration.

Towing Capacity:

Up to 5,000 lbs (2268 kg) with proper equipment and engine configuration.

🛡️ Safety Features

NHTSA Frontal Impact:

Not specifically rated by NHTSA in a manner directly comparable to modern standards; however, it was designed to meet federal safety regulations of its time.

ABS:

Anti-lock Braking System (ABS) typically standard on rear wheels, optional on all four wheels depending on trim and driveline.

Airbags:

Driver and passenger front airbags standard.

Seat Belts:

Three-point seat belts for front occupants; two-point lap belts for rear occupants in Extended/Access Cabs.

💡 Technology Features

Audio Options:

Factory-installed AM/FM radio with cassette player was standard. Optional upgrades included CD players and premium speaker systems.

Display Type:

Analog gauges with indicator lights. No digital displays or touchscreens.

Cruise Control:

Optional, typically controlled via steering wheel or stalk.

Traction Control:

Not generally available on this model year, especially on base trims or 2WD variants.

Phone Integration:

None. Bluetooth and smartphone integration were not features of this era.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-7,500 miles (5,000-12,000 km) or 6-12 months, depending on driving conditions and oil type. Owner's manual will provide specific guidance.

Engine Air Filter Replacement:

Every 15,000-30,000 miles (24,000-48,000 km) or as needed based on inspection.

Transmission Fluid Change:

Typically every 30,000-60,000 miles (48,000-96,000 km), depending on transmission type and driving conditions.

Engine Oil Viscosity:

Typically SAE 5W-30 for both 4-cylinder and V6 engines, but manual will confirm.

Coolant Type:

Dex-Cool (GM's orange extended-life coolant) or equivalent silicate-free, ethylene glycol-based coolant.

Brake Fluid Type:

DOT 3 brake fluid.

Power Steering Fluid:

Dexron III (or equivalent) automatic transmission fluid is often specified for GM power steering systems of this era.

Common Wear Items:

U-joints, ball joints, tie rod ends, exhaust system components, brake pads/rotors, clutch wear (manual transmission).

Engine Specific Concerns:

The 4.3L V6 can experience intake manifold gasket leaks; the 2.2L 4-cylinder may develop oil leaks or timing chain noise over time.

Transmission Issues:

Automatic transmissions can sometimes develop issues with solenoids or torque converters; manual transmissions are generally robust but clutch wear is normal.

Oil Filter Example:

AC Delco PF1218 or equivalent (typical for 4.3L V6), PF2223 or equivalent (typical for 2.2L 4-cyl). Exact OEM number would be in a parts catalog, owner's manual focuses on type.

Air Filter Example:

AC Delco A1166C or equivalent (typical for 4.3L V6), A1581C or equivalent (typical for 2.2L 4-cyl). Exact OEM number would be in a parts catalog, owner's manual focuses on type.

📚 Vehicle History

Gmc Truck Legacy:

GMC has a long history of building trucks, known for durability and work capability. The Sonoma nameplate replaced the S-15 Jimmy/pickup truck lineage.

Second Generation:

The 1999 Sonoma is part of the second generation of the compact pickup truck, which debuted for the 1998 model year. It shared its platform with the Chevrolet S-10 and featured updated styling and chassis compared to the first generation.

Production Years:

Second generation: 1998-2004.

Manufacturing Locations:

Shreveport, Louisiana; Moraine, Ohio.

🏆 Awards & Recognition

Truck Of The Year:

While not specifically for the 1999 Sonoma, its sibling, the Chevrolet S-10, received multiple 'Truck of the Year' awards in the past from various automotive publications for its generation.

Consumer Reports Reliability:

Reliability ratings varied by year and specific configuration. Owner's manual is essential for proper maintenance to maximize longevity.