🏷️ Basic Information Identification Make: Mercedes-Benz Model: S-Class Model Variant: S550 Year: 2009 Codes Chassis Code: W221 👋 Introduction Market Position Segment: Full-size Luxury Sedan Target Audience: Affluent consumers seeking comfort, performance, advanced technology, and prestige. Competitive Analysis Key Competitors: BMW 7 Series, Audi A8, Lexus LS, Porsche Panamera, Jaguar XJ. Key Features Vehicle Focus: Represents the pinnacle of Mercedes-Benz engineering, comfort, and technology for its era. Manual Purpose: To guide owners on proper operation, maintenance, and understanding of their S550's extensive features. 📋 Manual Details Coverage Areas Primary Focus: Owner's Information and Operation Secondary Focus: Basic Maintenance and Specifications Page Count Estimated Page Count: Approximately 400-500 pages (typical for this model year and complexity) Manual Type Type: Owner's Manual Language Language: English Format Format: Digital PDF 📖 Manual Coverage Systems Covered Powertrain: Engine operation, fuel system, cooling system, exhaust system (overview). Chassis: Braking system operation, suspension overview, steering system operation. Electrical: Lighting systems, power windows, door locks, seat adjustments, infotainment system basics, instrument cluster functionality. Comfort And Convenience: Climate control system operation, seating adjustments, interior features, trunk operation, keyless-go functionality. Safety And Security Safety Restraints: Airbag system, seat belt operation and adjustments, child seat installation guidance. Security Features: Central locking, anti-theft alarm system, immobilizer. Procedures Included Operation: Starting and driving the vehicle, parking, using various vehicle controls and features. Maintenance Basic: Checking engine oil level, checking coolant level, checking tire pressure, windshield washer fluid refill, basic cleaning procedures. Emergency Procedures: Changing a flat tire (if applicable and basic steps), jump-starting the vehicle (overview), warning indicator explanations. Technical Depth Depth: Designed for the end-user to understand and operate the vehicle safely and effectively. Covers fundamental maintenance tasks and system operation, not in-depth repair diagnostics or procedures. 📊 Manual Specifications File Format Format: PDF Readability: Requires PDF reader (e.g., Adobe Acrobat Reader, Foxit Reader). Searchability: Likely contains searchable text content for efficient information retrieval. Print Quality Quality: Digital reproduction of factory original, expected to be high quality for clarity of text and images. Binding Type Type: N/A (Digital Download) Paper Type Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Code: M273 (likely) Engine Type: Naturally Aspirated V8 Displacement: 5.5 Liters (5461 cc) Performance Horsepower: 382 hp @ 6000 rpm Torque: 391 lb-ft @ 2800-4000 rpm Fuel System Fuel Delivery: Electronic Fuel Injection (EFI) Fuel Type: Premium Unleaded Gasoline (91 Octane or higher recommended) 🔧 Transmission Standard Transmission Type: 7-speed Automatic (7G-TRONIC) Optional Drivetrain: Rear-Wheel Drive (RWD) standard, 4MATIC All-Wheel Drive (AWD) optional. Features Shifting Modes: Comfort (C) and Sport (S) modes. 📐 Dimensions Exterior Length: 200.0 inches Width: 73.7 inches Height: 57.7 inches Wheelbase: 117.7 inches Weights Curb Weight: 4,550 - 4,790 lbs (depending on RWD/4MATIC) Gross Vehicle Weight Rating: Approx. 5,840 lbs 🛡️ Safety Features Ratings NHTSA Front Crash Test: 5-Star (for comparable model years and safety equipment, specific rating for 2009 may vary by configuration) IIHS Top Safety Pick: Likely a Top Safety Pick for its year, reflecting advanced safety engineering. Active Features Stability Control: Electronic Stability Program (ESP) Braking Systems: Anti-lock Braking System (ABS), Brake Assist (BAS), Electronic Brake-force Distribution (EBD). Passive Features Airbags: Front, side, curtain, and knee airbags (driver and passenger). Seat Belts: 3-point inertia-reel seat belts with pre-tensioners and force limiters. 💡 Technology Features Infotainment Infotainment System: COMAND APS (Cockpit Management and Navigation Display) with hard-drive navigation, radio, CD/DVD changer, and SD card slot. Audio System: Harmon Kardon Logic 7 surround sound system often standard or optional. Driver Assistance Adaptive Cruise Control: DISTRONIC PLUS (optional feature for adaptive cruise control with enhanced distance sensing). Parking Assistance: PARKTRONIC parking assist system (front and rear sensors) often standard, rearview camera optional. Lane Keeping: LANE KEEPING ASSIST (optional) and BLIND SPOT ASSIST (optional). Connectivity Phone Integration: Bluetooth interface for hands-free calling and audio streaming. 🔧 Maintenance Service Intervals Oil Change Interval: Typically every 10,000 miles or 12 months, whichever comes first (as per Flexible Service System, actual may vary based on driving conditions). Major Service Interval: Major services (e.g., spark plugs, transmission fluid, brake fluid) are usually scheduled at higher mileage intervals (e.g., 40,000-60,000 miles). Fluid Specifications Engine Oil Specification: MB 229.5 (e.g., Mobil 1 0W-40 Synthetic, Castrol Syntec 0W-40) Engine Oil Capacity: Approximately 8.5 US quarts (with filter) Coolant Specification: MB 325.0 (Antifreeze/Coolant Concentrate, typically a silicate-based, long-life formulation). Brake Fluid Specification: DOT 4 Plus (MB 331.0) Transmission Fluid Type: MB 236.14 (ATF for 7G-TRONIC transmissions) Air Filter Part Number: Refer to specific dealer or parts catalog (e.g., Bosch F026400009, Mann-Filter C30120/1-2 are common aftermarket equivalents). Known Issues Common Issues Early W221: Potential issues with ABC (Active Body Control) suspension, EIS (Electronic Ignition Switch) failures, SBC (Sensotronic Brake Control) system faults (though SBC was phased out by 2009 in favor of conventional hydraulic brakes assisted by ESP), COMAND system glitches, and oil leaks from valve...