🏷️ Basic Information

Make:

Mercedes-Benz

Model:

S420

Year:

1999

Chassis Code:

W220

Generation Name:

W220 (First Generation)

Generation Years:

1998-2005

👋 Introduction

Market Position:

The 1999 Mercedes-Benz S420 (W220) represented the pinnacle of luxury and technology for its era, competing directly with flagship sedans from BMW (7 Series), Audi (A8), and Lexus (LS Series). It was positioned as a sophisticated and technologically advanced vehicle for discerning buyers valuing comfort, safety, and prestige.

Competitive Analysis:

While competitors offered strong performance and luxury, the W220 S-Class was noted for its innovative technology, refined ride quality (especially with AIRMATIC), and advanced safety features. This manual provides the essential information to maintain and repair these sophisticated systems, distinguishing it from simpler domestic or lower-tier luxury vehicles.

Key Features:

The 1999 S420, powered by a V8 engine, featured advancements like CAN bus data networks, sophisticated electronic stability programs, advanced climate control, and optional features like GPS navigation and adaptive cruise control (Distronic). This manual is crucial for understanding and servicing these complex electronic and mechanical systems.

📋 Manual Details

Coverage Areas:

Engine, Transmission, Drivetrain, Suspension, Steering, Brakes, Electrical System, HVAC, Body, Interior, Diagnostics, Maintenance, Troubleshooting, Specifications, Wiring Diagrams

Page Count:

Estimated 2000+ pages (typical for comprehensive factory service manuals)

Manual Type:

Official Service and Repair Manual Software

Language:

English

Format:

Software (likely PDF or proprietary viewer)

📖 Manual Coverage

Systems Covered:

Engine Mechanical (M112 V6, M113 V8), Engine Management (ME 2.0/2.8), Fuel System, Ignition System, Emission Control, Cooling System, Lubrication System, Intake System, Exhaust System, Automatic Transmission (5G-TRONIC 722.6), Drivetrain (Rear Wheel Drive), Suspension (Front & Rear Independent, AIRMATIC DC optional), Steering System (Hydraulic Power), Brake System (ABS, ESP, SBC optional), Electrical System (12V System, Charging System, Starting System, Lighting, Instrumentation, Body Electronics, CAN Bus Communication), Climate Control (Thermotronic), SRS Airbag System, Interior Systems, Exterior Body Panels, Chassis Components

Procedures Included:

Routine Maintenance (Oil Change, Fluid Checks, Filter Replacements), Component Removal and Installation, System Diagnosis and Troubleshooting, Electrical Component Testing, Engine Rebuilding, Transmission Overhaul, Suspension Component Replacement, Brake System Servicing, HVAC System Repair, Bodywork Repair Procedures, Wiring Diagram Interpretation, Diagnostic Trouble Code (DTC) Analysis and Resolution

Technical Depth:

Comprehensive - from basic scheduled maintenance and fluid changes to in-depth engine and transmission overhaul, complex electrical diagnostics, and body panel repair. Includes torque specifications, tolerances, and detailed assembly/disassembly instructions.

Wiring Diagrams Included:

Yes, comprehensive wiring diagrams for all major electrical systems.

📊 Manual Specifications

File Format:

Digital Software (likely searchable PDF or dedicated application)

Print Quality:

N/A (Digital Format)

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

Completeness:

Full Factory Service Manual equivalent, providing complete diagnostic and repair procedures for all systems.

⚙️ Engine Specifications

Engine Code:

M113 E43

Engine Type:

4.3L (4266cc) SOHC V8

Horsepower:

275 hp @ 5750 rpm

Torque:

295 lb-ft @ 3750 rpm

Fuel Injection:

Electronic Fuel Injection (EFI) - Bosch Motronic ME 2.0/2.8

Fuel Type:

Premium Unleaded Gasoline (91+ Octane)

Bore X Stroke:

97.0 mm x 92.0 mm

Compression Ratio:

10.0:1

Engine Oil Capacity:

8.0 Liters (8.5 US Quarts) with filter change

Engine Oil Specification:

API SJ or ACEA A3/B3, Viscosity SAE 0W-40 or 5W-40 (MB Approved 229.5)

Valve Train:

SOHC (Single Overhead Camshaft) with 3 valves per cylinder (2 intake, 1 exhaust) operated by two spark plugs per cylinder (dual ignition).

Spark Plugs Per Cylinder:

2 (Dual Ignition)

🔧 Transmission

Transmission Type:

5-Speed Automatic (5G-TRONIC)

Transmission Code:

722.6

Transmission Features:

Electronic Control, Adaptive Shift Program (ASP), Torque Converter Lock-up

Shift Modes:

Comfort (C) and Sport (S) modes.

Transmission Fluid Type:

MB Specification 236.10 (ATF 3353) or equivalent approved fluid (e.g., Pentosin ATF1)

Transmission Fluid Capacity:

Approximately 8.0 - 9.5 Liters (for a complete drain and fill, depending on torque converter fill)

📐 Dimensions

Length:

199.4 inches (5065 mm)

Width:

73.7 inches (1872 mm)

Height:

57.4 inches (1458 mm)

Wheelbase:

116.5 inches (2960 mm)

Curb Weight:

Approximately 3900 - 4100 lbs (1769 - 1860 kg)

Gross Vehicle Weight Rating:

Approximately 5400 lbs (2450 kg)

Front Headroom:

Approx. 38.4 inches

Front Legroom:

Approx. 41.7 inches

Rear Headroom:

Approx. 38.0 inches

Rear Legroom:

Approx. 43.1 inches

🛡️ Safety Features

NHTSA Front Impact Rating:

5-Star (Driver and Passenger)

IIHS Front Offset Crash Rating:

Good

Active Safety Features:

Anti-lock Braking System (ABS), Electronic Stability Program (ESP), Traction Control System (TCS), Brake Assist (BAS)

Passive Safety Features:

Front Airbags, Side Airbags (Front and Rear Optional), Seatbelt Pretensioners, Crumple Zones, High-Strength Steel Body Structure

Seat Belt Features:

Pretensioners and force limiters on front seats.

💡 Technology Features

Infotainment System:

COMAND (Cockpit Management and Navigation Display) - Optional, featured CD-based navigation, radio, and climate control interface.

Driver Assistance Features:

Optional Distronic Adaptive Cruise Control, Parking Assist Sensors (front and rear)

Connectivity Features:

Integrated Tele Aid emergency calling system (subscription-based), Optional Mercedes-Benz In-Car Phone

Other Technology:

Keyless Go (Push-button start, optional), Bi-Xenon Headlights (optional), Rain-sensing wipers, Automatic climate control (Thermotronic)

🔧 Maintenance

Oil Change Interval:

Variable (depending on driving conditions, typically 7,500-10,000 miles or 12-18 months, indicated by 'Service A' or 'Service B' on the dashboard).

Transmission Service Interval:

Recommended every 60,000 miles or 4 years for filter and fluid change.

Coolant Service Interval:

Initial change at 100,000 miles, then every 50,000 miles or 2 years thereafter.

Coolant Type:

MB Specification 325.0 (Proprietary Blue Coolant or equivalent)

Brake Fluid Type:

DOT 4 Plus (MB Specification 331.0)

Power Steering Fluid Type:

MB Specification 236.3 (ATF Dexron III compatible, or specific hydraulic fluid)

Known Issues:

Ignition coil failures, Crankshaft position sensor issues, ABS/ESP module failures (especially related to SBC on later models, though less common on '99), Biodegradable wiring harness insulation breakdown, Sunroof drain tube blockage leading to water ingress, Electronic modules (SAM, EIS) glitches, Lower control arm bushings wear, Oil leaks from valve cover gaskets and oil filter housing.

Airmatic Suspension Issues:

Leaking air springs/struts, compressor failure, valve block leaks, control module issues.

📚 Vehicle History

Brand Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, and safety, dating back to the invention of the automobile. The S-Class lineage represents the brand's flagship sedan, consistently pushing the boundaries of automotive technology and comfort.

Model Evolution:

The W220 generation replaced the W140 S-Class, aiming for a more aerodynamic and less imposing design. It introduced significant advancements in electronics, weight reduction (using aluminum extensively), and ride comfort, setting new benchmarks for the luxury sedan segment.

Key Technological Advancements In W220:

All-aluminum multi-link front suspension, AIRMATIC Dual Control air suspension, CAN bus multiplexing, COMAND infotainment system.

Production Years:

1998-2005

Manufacturing Locations:

Germany (Sindelfingen Plant)