🏷️ Basic Information Identification Make: Mercedes-Benz Model: S550 Year: 2009 Codes Chassis Code: W221 Engine Code: M273.961 👋 Introduction Market Position Segment: Full-size Luxury Sedan Competitive Analysis Key Competitors: BMW 7 Series, Audi A8, Lexus LS, Porsche Panamera Key Features Luxury Appointments: Premium materials, advanced comfort features, sophisticated styling Technology Integration: Advanced driver assistance systems, sophisticated infotainment, innovative comfort technologies Target Audience Demographic: Affluent consumers seeking premium performance, comfort, and cutting-edge technology 📋 Manual Details Coverage Areas Coverage Scope: Comprehensive service and repair Page Count Estimated Pages: Thousands (typical for full factory service data) Manual Type Type: Official Factory Service and Repair Manual Software Language Language: English Format Format: Software (Digital) 📖 Manual Coverage Systems Covered Powertrain: Engine (M273), Transmission (722.9 7G-TRONIC PLUS), Drivetrain (4MATIC AWD optional) Chassis: Suspension (AIRMATIC DC), Steering (Electro-hydraulic), Brakes (ABS, ESP, SBC - if applicable, though W221 primarily uses Sensotronic Brake Control variants or conventional hydraulic systems depending on build date/options) Electrical Electronics: Body Control Module (BCM), CAN Bus Communication, Lighting Systems, Infotainment (COMAND APS), Navigation, Climate Control (THERMATIC/THERMOTRONIC), Instrument Cluster, Keyless-Go, Power Seats, Power Windows, Power Sunroof, Parking Assist (PARKTRONIC) Body Exterior: Body panels, doors, hood, trunk, bumpers, glass, mirrors, convertible top (if applicable - not for S550 sedan), convertible drive system (if applicable) Body Interior: Interior trim, upholstery, airbags, seat belts, HVAC ducting, dashboard, center console Procedures Included Maintenance: Scheduled maintenance (oil changes, filter replacements, fluid checks), brake pad/rotor replacement, battery service, spark plug replacement, belt replacement Diagnostics: Troubleshooting guides, DTC (Diagnostic Trouble Code) lookup and interpretation, wiring diagrams, component testing Repair Rebuild: Engine component repair, transmission overhaul, suspension component replacement, brake system repair, electrical component repair, body panel repair Calibration Adaptation: Throttle body adaptation, steering angle sensor calibration, suspension height calibration, module programming/coding (requires Mercedes-Benz diagnostic tools) Technical Depth Depth: Expert level: Covers detailed diagnostic procedures, component-level repair, electrical schematics, torque specifications, and factory procedures for all major systems. 📊 Manual Specifications File Format File Type: Proprietary software or PDF bundle Print Quality Print Option: Printable (high-resolution diagrams and text) Binding Type Binding: N/A (Digital Software) Paper Type Paper: N/A (Digital Software) ⚙️ Engine Specifications Primary Engine Engine Type: Naturally Aspirated V8 Displacement: 5.5 Liters (5461 cc) Bore X Stroke: 98.0 mm x 90.5 mm Compression Ratio: 10.7:1 Performance Horsepower: 382 hp @ 6000 rpm Torque: 391 lb-ft @ 2800-4500 rpm Fuel System Induction: Multi-point Fuel Injection (MPI) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Engine Management ECU: ME 9.7 🔧 Transmission Standard Type: 7-speed Automatic (7G-TRONIC PLUS) Gear Ratios: 4.377 / 2.859 / 1.926 / 1.370 / 1.000 / 0.745 / 0.695 (Rear) Optional Drive Type: 4MATIC All-Wheel Drive (Optional) Features Modes: Comfort (C), Sport (S), Manual (M) Fluid Specifications Fluid Type: MB 236.14 Automatic Transmission Fluid 📐 Dimensions Exterior Length: 206.5 in (5245 mm) Width: 74.9 in (1902 mm) Height: 58.1 in (1476 mm) Wheelbase: 124.6 in (3165 mm) Weights Curb Weight: 4674 lbs (2120 kg) RWD, 4784 lbs (2169 kg) AWD Gross Vehicle Weight Rating: 6283 lbs (2850 kg) 🛡️ Safety Features Ratings NHTSA Front Impact: 5-Star NHTSA Side Impact: 5-Star IIHS Top Safety Pick: Yes Active Features Brake Assist Plus: Standard Esp: Electronic Stability Program Adaptive Cruise Control: DISTRONIC PLUS (Optional) Lane Departure Prevention: LANE KEEPING ASSIST (Optional) Passive Features Airbags: Front dual-stage, front side-impact, rear side-impact, front and rear head curtain airbags Seat Belts: Pre-tensioners, force limiters, automatic height adjustment 💡 Technology Features Infotainment Head Unit: COMAND APS (Cockpit Management and Navigation) Navigation: Hard-drive based GPS navigation system Audio System: Harman Kardon LOGIC 7 surround sound system (Optional) Driver Assistance Parking Assist: PARKTRONIC (Optional) Blind Spot Monitoring: BLIND SPOT ASSIST (Optional) Night Vision: NIGHT VIEW ASSIST (Optional) Connectivity Bluetooth: Bluetooth interface for hands-free calling and audio streaming Auxiliary Input: Yes (AUX input for external audio devices) Comfort Features Climate Control: THERMATIC (Dual-zone) or THERMOTRONIC (Multi-zone) automatic climate control Seats: Heated and ventilated front seats, optional multi-contour seats with massage function Lighting Headlights: Bi-Xenon Adaptive Headlights with LED Daytime Running Lights 🔧 Maintenance Service Intervals Oil Change Interval: Every 10,000 miles or 12 months (whichever comes first), using synthetic oil meeting MB 229.5 specification. Air Filter Replacement: Every 30,000 miles or 3 years. Cabin Filter Replacement: Every 15,000 miles or 2 years. Spark Plug Replacement: Every 100,000 miles for iridium spark plugs (specific part numbers in manual). Fluid Specifications Engine Oil Capacity: Approx. 8.5 liters (8.9 US quarts) Coolant Type: Mercedes-Benz Approved Antifreeze/Coolant (e.g., MB 325.0 or MB 326.0) Brake Fluid Type: DOT 4 Plus Known Issues Airmatic Suspension: Potential for air strut leaks, compressor failure, or sensor malfunctions over time. Manual covers diagnosis and repair. Ignition Coils: Some M273 engines can experience ignition coil failures, leading to misfires. Manual provides diagnostic steps. Cooling System: Water pump and thermostat failures can occur. Manual details replacement...