🏷️ Basic Information

Make:

Mitsubishi

Model:

Sigma

Years Covered:

1990, 1991, 1992, 1993, 1994, 1995

Platform:

Mitsubishi Sigma (often referred to as the Mitsubishi Diamante in some markets, specifically this generation)

👋 Introduction

Segment:

Full-size luxury/executive sedan positioned against competitors like Toyota Avalon, Buick LeSabre, Ford Taurus, and European sedans of the era.

Key Selling Points:

Known for its comfortable ride, spacious interior, powerful V6 engine options, and distinctive styling. Often praised for value compared to premium European brands.

Manual Value Proposition:

Empowers owners and independent mechanics with factory-level repair information, enabling cost savings on maintenance and repairs, and facilitating informed discussions with technicians.

📋 Manual Details

Market Segment:

Full-size/Large Sedan, Executive Car

Estimated Page Count:

Likely between 1000-2000 pages (typical for comprehensive workshop manuals of this era)

Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Complete engine overhaul, including cylinder head, block, pistons, crankshaft, camshafts, timing systems.

Engine Electrical:

Ignition system, starting system, charging system, engine control unit (ECU), sensors, wiring diagrams.

Emission Control:

EGR system, catalytic converter, evaporative emission control (EVAP), emission control sensors.

Fuel System:

Fuel injection system (MPI), fuel pump, fuel filter, injectors, fuel pressure regulator, fuel tank.

Clutch System:

Clutch operation, clutch master cylinder, slave cylinder, clutch disc, pressure plate, release bearing.

Manual Transaxle:

Gearbox disassembly, assembly, lubrication, shift linkage, internal components.

Automatic Transaxle:

Transmission operation, valve body, torque converter, shift solenoids, hydraulic control, fluid service, diagnostics.

Drivetrain:

Driveshaft, CV joints, differential, wheel bearings, hub assemblies.

Suspension:

Front and rear suspension components, shock absorbers, struts, springs, control arms, ball joints, bushings, alignment specifications.

Steering:

Power steering system, steering rack, tie rods, steering column, wheel alignment.

Restraint System:

Seat belts, airbags (if equipped), SRS system diagnostics and service.

Brake System:

Front and rear brakes (disc/drum), hydraulic system, ABS (if equipped), brake fluid specifications, bleeding procedures, rotor/pad replacement.

Body Interior:

Interior trim removal and installation, seats, dashboard, door panels, carpeting.

Body Exterior:

Exterior trim, bumpers, fenders, hood, trunk, doors, glass, seals.

Body Electrical:

Lighting, power windows, power locks, mirrors, wipers, horn, instrument cluster, audio system wiring.

HVAC:

Heating, ventilation, and air conditioning (HVAC) system, refrigerant, compressor, condenser, evaporator, blower motor, controls.

Maintenance:

Routine maintenance tasks such as oil changes, filter replacements, spark plug changes, fluid checks and top-offs.

Diagnostics:

Troubleshooting guides for common problems, diagnostic trouble codes (DTCs) interpretation, component testing procedures.

Repair:

Step-by-step instructions for component replacement and repair across all major vehicle systems.

Wiring Schematics:

Detailed electrical wiring diagrams for all vehicle circuits.

Specifications:

Torque specifications, clearances, fluid capacities, performance data, and other critical technical data.

Depth:

Comprehensive (covers basic maintenance to major overhauls and diagnostics).

📊 Manual Specifications

PDF Quality:

High resolution, text-searchable for ease of navigation and printing.

Printability:

All pages are printable, allowing users to print specific sections as needed.

Binding:

Digital (PDF) - No physical binding

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Options:

Typically offered with V6 engines. Common variants include the 3.0L (6G72) and 3.5L (6G73) SOHC/DOHC V6.

Horsepower Range:

Approximately 150-220 hp depending on engine and year.

Torque Range:

Approximately 170-230 lb-ft depending on engine and year.

Injection Type:

Multi-Point Fuel Injection (MPI)

🔧 Transmission

Standard Transmission:

Automatic Transaxle (likely 4-speed)

Optional Transmission:

Manual Transaxle (less common, but potentially available on certain trims or markets)

Drive Layout:

Front-Wheel Drive (FWD)

📐 Dimensions

Wheelbase:

Approximately 107.1 inches (2720 mm)

Length:

Approximately 191.7 inches (4870 mm)

Curb Weight:

Approximately 3300-3600 lbs (1500-1630 kg) depending on configuration.

🛡️ Safety Features

Crash Test Data:

Information on crashworthiness specific to these years would be detailed in the manual if available from NHTSA or IIHS for the period.

Active Safety:

Anti-lock Braking System (ABS) likely available or standard on higher trims.

Passive Safety:

Seat belts, potentially driver-side airbag (standard on later models/trims), reinforced safety cage.

💡 Technology Features

Audio System:

Factory AM/FM stereo with cassette player, optional CD player. Speaker configuration varied by trim level.

Driver Aids:

ABS was a key driver assistance feature. Cruise control was also common.

Connectivity Features:

Limited by modern standards; primarily focused on in-car entertainment. Power accessories (windows, locks) were considered advanced features.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles (4,800-8,000 km) or 3-6 months, using appropriate oil viscosity (e.g., 10W-30, 5W-30 depending on climate).

Spark Plug Replacement:

Around 30,000-60,000 miles (48,000-96,000 km), depending on spark plug type (copper vs. platinum/iridium).

Engine Oil Type:

API SG or higher, SAE 10W-30 or 5W-30 (refer to manual for exact specification and capacity).

Coolant Type:

Ethylene glycol based, typically a green coolant. Capacity around 8-10 quarts (7.5-9.5 liters). Refer to manual for exact type and mixture.

Transmission Fluid Type:

ATF SP-II or SP-III for automatic transmissions; Gear oil (e.g., GL-4) for manual transmissions. Refer to manual for exact specification and capacity.

Common Problems:

Potential issues may include wear in suspension bushings, aging rubber components, cooling system leaks, and minor electrical gremlins common in vehicles of this age. Timing belt replacement is critical for interference engines.

📚 Vehicle History

Heritage:

Mitsubishi Motors, a major Japanese automotive manufacturer with a history dating back to the early 20th century, known for robust engineering.

Generation:

This generation (JA/JB series) was a significant evolution, adopting a more aerodynamic and luxurious styling. It shared platform components with other Mitsubishi vehicles of the era.

Manufacturing Location:

Primarily Japan, with potential assembly in other global locations.

🏆 Awards & Recognition

Industry Accolades:

While specific awards for the Sigma are less documented, Mitsubishi models of this era were generally recognized for their value and reliability within their segments.