🏷️ Basic Information

Make:

Audi

Model:

S4

Year:

1993

Chassis Code:

B4

Engine Code Primary:

ABDC

👋 Introduction

Segment:

Performance Sedan (Sport Compact)

Competitors 1993:

BMW 325i, Mercedes-Benz 190E 2.3-16, Ford Sierra Cosworth, Lancia Delta Integrale

Vehicle Focus:

The 1993 Audi S4 represents a significant step in Audi's performance lineage, offering a blend of Quattro all-wheel-drive traction and turbocharged power, targeting enthusiasts who value sophisticated engineering and potent, all-weather performance.

Manual Value Proposition:

This wiring diagram service manual is essential for diagnosing and repairing the complex electrical systems of the 1993 Audi S4, empowering DIY enthusiasts and professional technicians alike with critical visual and diagnostic information.

📋 Manual Details

Scope:

Wiring Diagrams and Electrical Systems

Estimated Pages:

150-250

Type:

Service Repair Manual (Wiring Diagrams Focus)

Language:

English

Format:

PDF Download

📖 Manual Coverage

Electrical Systems:

Engine Control Unit (ECU), Ignition System, Fuel Injection System, Lighting (Headlights, Taillights, Interior), Instruments and Gauges, Audio System, Power Windows, Power Locks, Climate Control, ABS System, Airbag System (if equipped), Wiper/Washer System, Horn, Antennas

Electrical Troubleshooting:

Component location, Circuit diagnosis, Fuse and relay identification, Wire harness routing, Connector pinouts, Voltage drop testing, Continuity testing, Fault finding charts

Depth:

Detailed electrical schematics, Component identification, System descriptions, Troubleshooting procedures for electrical faults

📊 Manual Specifications

Compatibility:

All Versions of Windows & Mac

Readability:

High-resolution, searchable PDF for clear diagram viewing and text extraction

Binding:

N/A (Digital Download)

Paper:

N/A (Digital Download)

Software Requirements:

Adobe PDF Reader

⚙️ Engine Specifications

Engine Type:

Inline 5-Cylinder, turbocharged, intercooled

Displacement:

2.2 Liters (2226 cc)

Horsepower:

227 hp @ 5900 rpm

Torque:

257 lb-ft @ 3000 rpm

Fuel Delivery:

Bosch Motronic Electronic Fuel Injection (EFI)

Turbocharger Details:

Garrett T3 Turbocharger, Air-to-Air Intercooler

ECM:

Bosch Motronic M2.3.2

🔧 Transmission

Transmission Type:

5-Speed Manual

Transmission Type:

4-Speed Automatic (Tiptronic on some later models, but not standard for 1993 S4)

Drivetrain:

Audi Quattro Permanent All-Wheel Drive

Clutch Type:

Hydraulically Actuated Single Dry Plate

📐 Dimensions

Length:

4720 mm (185.8 in)

Width:

1750 mm (68.9 in)

Height:

1420 mm (55.9 in)

Curb Weight:

1530 kg (3373 lbs)

Gross Vehicle Weight Rating:

2010 kg (4431 lbs)

🛡️ Safety Features

Federal Crash Test Rating:

Not comprehensively rated by NHTSA for this era. Emphasis on structural integrity and driver control via Quattro.

Braking System:

Front: Ventilated Discs, Rear: Solid Discs, Anti-lock Braking System (ABS) standard

Airbags:

Driver-side airbag standard

Seatbelts:

3-point inertia-reel seatbelts with pretensioners (front)

Body Structure:

Advanced safety cage construction for the era

💡 Technology Features

Audio System:

Audi Gamma or Concert CD stereo systems, often with amplifier and subwoofer options.

ABS:

Standard Anti-lock Braking System (ABS)

ECU Integration:

Integrated engine and drivetrain management via Bosch Motronic system, crucial for the turbocharged 5-cylinder performance.

🔧 Maintenance

Oil Change Interval:

7,500 miles or 12 months, whichever comes first (synthetic oil recommended)

Timing Belt Replacement:

Recommended every 60,000 miles or 5 years (critical due to interference engine design)

Engine Oil Type:

API SG or SH, SAE 5W-40 or 10W-40 (check owner's manual for precise recommendation)

Coolant Type:

G12 (VW/Audi specific pink coolant) or equivalent silicate-free antifreeze (50/50 mix with distilled water)

Transmission Fluid Type Manual:

API GL-4 SAE 75W-90 (or equivalent)

Differential Fluid Type:

API GL-5 SAE 75W-90 (or equivalent)

Common Wear Items:

Turbocharger seals, intercooler hoses, ignition components (coil packs, spark plug wires), fuel injectors, catalytic converter, suspension bushings, ABS sensors.

Electrical Gremlins:

Common for this era and complexity, particularly related to wiring harness degradation, ground points, and ECU connections. This manual is crucial for addressing these.

Critical Maintenance:

The manual will detail the importance of regular checks and replacement of ignition and fuel system components for optimal performance and reliability of the turbocharged engine. Timing belt replacement is non-negotiable.

📚 Vehicle History

Brand Focus:

Audi has a long history of innovation, particularly with its Quattro all-wheel-drive system, which debuted in rally racing and was later integrated into its production vehicles, defining the brand's performance identity.

Platform:

Audi 80/90 (B4) platform

Performance Variant:

The S4 designation signified the highest performance variant of the Audi 100/A6 family in earlier generations, but for the B4 generation, the 'S4' name was applied to the performance version of the Audi 80/90 sedan, bridging the gap and offering a more compact performance package.

Production Years:

1991-1994 (for the B4 platform S4)

Manufacturing Location:

Ingolstadt, Germany

🏆 Awards & Recognition

Performance Accolades:

While specific awards for the 1993 S4 may be limited, the car inherited the reputation for robust engineering and performance associated with Audi's S-model lineage and the acclaimed Quattro system.

Vehicle Magazine Reviews:

Consistently reviewed positively for its all-weather capability, strong engine performance, and comfortable ride, though sometimes criticized for turbo lag compared to some rivals.