🏷️ Basic Information

Make:

GMC

Model:

Sierra 1500

Year:

1999

Generation:

Third Generation (GMT800)

👋 Introduction

Market Position:

Essential diagnostic and repair resource for owners and independent repair facilities of the 1999 GMC Sierra 1500, offering a cost-effective alternative to traditional printed manuals and dealership services.

Competitive Analysis:

Provides a modern, accessible, and constantly updated alternative to older, often harder-to-find printed manuals. Leverages OE (Original Equipment) licensed data for accuracy and completeness, surpassing generic online forums or unofficial guides.

Key Features:

Licensed OE data, web-based accessibility across multiple devices, comprehensive coverage of all major systems, detailed troubleshooting, expert-level repair procedures, cost savings for DIY repairs, one-year access with renewal options.

📋 Manual Details

Coverage Areas:

Comprehensive repair and service information for the 1999 GMC Sierra 1500

Page Count:

Not specified (Software-based with extensive content)

Manual Type:

Service and Repair Manual Software

Language:

English

Format:

Online Software (Web-based access)

📖 Manual Coverage

Systems Covered:

Engine mechanical, engine performance, fuel system, cooling system, exhaust system, transmission (automatic and manual), drivetrain, axles, suspension (front and rear), steering, brakes (front and rear), electrical system (including wiring diagrams), HVAC (heating, ventilation, and air conditioning), body and frame, interior trim, diagnostics, troubleshooting

Procedures Included:

Routine maintenance, scheduled service, component inspection, diagnosis and testing, repair and replacement of all major systems, detailed troubleshooting guides, diagnostic trouble codes (DTCs), component specifications, torque values, alignments, fluid capacities and types

Technical Depth:

Factory-level technical data, including detailed component removal and installation, assembly and disassembly, diagnostic procedures, wiring schematics, and specifications for advanced repairs and rebuilds.

📊 Manual Specifications

File Format:

Web-based application (accessible via browser)

Print Quality:

N/A (Digital access, high-resolution digital content)

Binding Type:

N/A (Digital access)

Paper Type:

N/A (Digital access)

⚙️ Engine Specifications

Primary Engine:

4.8L V8 (Vortec 4800 L31)

Engine Options:

5.3L V8 (Vortec 5300 LM7), 6.0L V8 (Vortec 6000 LQ4 - typically for heavy-duty models but may be referenced for chassis similarities)

Horsepower:

4.8L: ~255 hp @ 5200 rpm; 5.3L: ~270 hp @ 5000 rpm

Torque:

4.8L: ~285 lb-ft @ 4000 rpm; 5.3L: ~315 lb-ft @ 4000 rpm

Fuel System:

Multi-port Electronic Fuel Injection (MPI)

Ignition System:

Distributorless Ignition System (DIS) with coil-on-plug ignition for some engines

Engine Codes:

L31 (4.8L), LM7 (5.3L), LQ4 (6.0L)

🔧 Transmission

Standard Transmission:

4L60-E 4-speed automatic

Optional Transmission:

NV3500 5-speed manual (RPO MW3)

Transmission Features:

Electronic control for 4L60-E, overdrive capability, lock-up torque converter.

📐 Dimensions

Wheelbase:

Varies by cab and bed configuration (e.g., 130 inches for standard cab long bed, 115 inches for regular cab short bed)

Length:

Varies by configuration (e.g., ~230 inches for extended cab short bed)

Width:

~78.5 inches

Height:

~73.4 inches

Curb Weight:

Approximately 4,500 - 5,500 lbs depending on configuration

Payload Capacity:

Up to ~2,200 lbs depending on configuration

Towing Capacity:

Up to ~8,800 lbs with proper equipment and configuration

🛡️ Safety Features

NHTSA Driver Front Impact:

4-star (for models tested, some variations exist)

NHTSA Passenger Front Impact:

4-star (for models tested, some variations exist)

Active Features:

Anti-lock Braking System (ABS) - standard on front wheels, optional on rear wheels

Passive Features:

Driver and passenger airbags, three-point seat belts with pretensioners, reinforced safety cage construction.

💡 Technology Features

Infotainment Features:

Basic AM/FM radio, optional CD player, optional premium sound system, manual climate controls.

Driver Assistance Features:

Cruise control (standard on most trims)

Connectivity Features:

N/A (No factory integrated Bluetooth or advanced connectivity)

🔧 Maintenance

Oil Change Interval:

Typically every 3,000 to 7,500 miles, depending on oil type (conventional vs. synthetic) and driving conditions. Consult the manual for specific recommendations.

Tire Rotation Interval:

Every 5,000 to 7,500 miles

Spark Plug Replacement:

Varies by plug type; typically around 100,000 miles for some extended-life plugs.

Engine Oil:

API SJ or higher, SAE 5W-30 recommended for most conditions (consult manual for specific viscosity based on temperature).

Transmission Fluid:

Dexron III (or equivalent) for 4L60-E automatic transmission. Manual transmission fluid varies by type (e.g., GL-4 or GL-5).

Coolant:

GM Goodwrench/Delco or equivalent, 50/50 mix of ethylene glycol antifreeze and distilled water.

Brake Fluid:

DOT 3

Power Steering Fluid:

GM Type A Suffix A or Dexron III

Known Issues:

Dashboard cracking (common on many GM vehicles of this era), intake manifold gasket leaks, rear main seal leaks, transmission cooler line leaks, fuel pump failures, catalytic converter issues.

📚 Vehicle History

Brand Heritage:

GMC (General Motors Truck Company) has a long history of producing robust and reliable trucks and commercial vehicles, dating back to 1911. Known for their heavy-duty capabilities and professional-grade design.

Model Evolution:

The 1999 Sierra 1500 is part of the GMT800 platform, which represented a significant redesign for GM's full-size trucks, introducing a more modern and aerodynamic exterior, improved interiors, and enhanced chassis dynamics. It replaced the older GMT400 platform.

Production Years:

1999-2006 (GMT800 platform)

Manufacturing Locations:

United States (e.g., Fort Wayne, Indiana; Pontiac, Michigan; Oshawa, Ontario, Canada)

🏆 Awards & Recognition

Recognitions:

The GMT800 platform trucks, including the Sierra, were generally well-received for their performance, ride comfort, and capability. Specific awards for the 1999 model year may include mentions in automotive publications for 'Best Pickup' or similar categories for their class.