Segment:
Full-size luxury sedan
Target Audience:
Affluent consumers seeking advanced technology, comfort, and performance.
Key Competitors:
BMW 7 Series, Audi A8, Lexus LS, Porsche Panamera, Jaguar XJ
Distinguishing Features:
Advanced driver assistance systems (PRE-SAFE, DISTRONIC PLUS), innovative suspension technology (AIRMATIC/ABC), luxurious interior appointments, powerful engine options, sophisticated COMAND infotainment.
Manual Purpose:
To provide official, detailed procedures for diagnosing, servicing, and repairing the 2012 Mercedes-Benz S-Class W221.
Powertrain:
Engine (all variants), Transmission (automatic), Drivetrain (rear-wheel drive, 4MATIC all-wheel drive)
Chassis:
Suspension (AIRMATIC, ABC), Steering, Brakes (including SBC/BAS/ABS/ESP), Wheels and Tires
Electrical And Electronics:
Body Control Module (BCM), Powertrain Control Module (PCM), Chassis Control Module (CCM), Infotainment System (COMAND), Navigation, Audio, Climate Control (THERMOTRONIC), Lighting (Bi-Xenon, LED), Instrument Cluster, CAN Bus diagnostics, Telematic systems
Body And Interior:
Exterior body panels, Doors, Hood, Trunk, Interior trim, Seats, Airbags, Seatbelts, Sunroof, Convertible top (if applicable)
Maintenance:
Scheduled maintenance (oil changes, filter replacements, fluid checks/changes), Inspection points, Lubrication
Diagnostics:
Troubleshooting guides, Diagnostic Trouble Codes (DTCs), Electrical schematic interpretation, Component testing, Sensor calibration
Repair:
Component removal and installation, Major overhauls, Specific repair procedures for all major systems, Engine rebuild, Transmission service, Suspension component replacement, Brake system repair
Technical Data:
Torque specifications, Lubricant specifications, Electrical component data, Measurement specifications
Depth:
Comprehensive, from basic fluid checks and filter changes to complete engine and transmission overhauls, advanced diagnostics, and electrical system troubleshooting.
File Type:
Portable Document Format (PDF)
Quality:
High-resolution scans of original factory documentation, ensuring clarity of diagrams, schematics, and text.
Binding:
Not applicable (Digital download)
Paper Quality:
Not applicable (Digital download)
Searchability:
Likely text-searchable PDF allowing for quick access to specific topics.
Accessibility:
Instant download to computer, tablet, or other compatible digital devices.
Expiry:
No expiry dates (one-time purchase)
Additional Fees:
No extra fees
Engine Family:
M272 (V6), M273 (V8), OM642 (V6 Diesel), M156/M159 (V8 AMG - may not be covered in standard manual)
S550 Engine:
4.7L (or 5.5L depending on specific model year variant within 2012) V8, approx. 382-429 hp, 391-516 lb-ft torque
S350 Bluetec Engine:
3.0L V6 turbodiesel (OM642), approx. 210 hp, 400 lb-ft torque
S63 Amg Engine:
5.5L Biturbo V8 (M157), approx. 536 hp, 590 lb-ft torque (check manual for specific AMG coverage)
Injection Type:
Sequential Multi-Port Fuel Injection (MPI) / Direct Injection (DI) depending on engine variant
Fuel Type:
Premium Unleaded Gasoline (91+ octane), Diesel for BlueTEC models
Coolant Type:
Mercedes-Benz approved blue coolant (e.g., G48 or equivalent)
Oil Type:
MB 229.5 or MB 229.51 approved synthetic engine oil (e.g., Mobil 1 0W-40, 5W-40 for diesel)
Type:
7G-TRONIC (722.9) 7-speed automatic transmission
Drivetrain Options:
4MATIC all-wheel drive (standard on some models)
Transmission Fluid:
MB 236.14 approved ATF (e.g., Shell ATF 134)
Torque Converter Lockup:
Electronically controlled torque converter lockup for improved efficiency
Length:
Approx. 5079-5208 mm (199.9-205.0 in)
Width:
Approx. 1871 mm (73.7 in)
Height:
Approx. 1473-1479 mm (58.0-58.2 in)
Wheelbase:
Approx. 3035-3165 mm (119.5-124.6 in) (standard and long wheelbase)
Curb Weight:
Approx. 1800-2050 kg (3968-4519 lbs)
Gross Vehicle Weight Rating:
Varies by model and options, typically around 2500-2700 kg
Trunk Volume:
Approx. 560 liters (19.8 cu ft)
NHTSA Rating:
Not directly applicable as tested in individual markets, but designed to high safety standards.
Braking Systems:
ABS, EBD, BAS (Brake Assist System), SBC (Sensotronic Brake Control - early W221), ESP (Electronic Stability Program)
Driver Assistance:
DISTRONIC PLUS (Adaptive Cruise Control), LANE KEEPING ASSIST, BLIND SPOT ASSIST, PARKTRONIC, NIGHT VIEW ASSIST
Airbags:
Frontal airbags (driver & passenger), Side airbags (front & rear), Window curtain airbags, Knee airbags (driver)
Pre Safe System:
PRE-SAFE anticipatory safety system that prepares occupant restraints and seating positions in potential collision scenarios.
Seatbelts:
3-point inertia-reel seatbelts with belt tensioners and force limiters
System Name:
COMAND (Cockpit Management and Navigation)
Features:
Navigation system, Radio (AM/FM/SiriusXM), CD/DVD player, MP3 compatibility, Bluetooth connectivity, auxiliary input.
Adaptive Cruise Control:
DISTRONIC PLUS provides automatic speed control based on traffic ahead.
Parking Assistance:
PARKTRONIC parking sensors with visual and audible alerts.
Telematics:
Optional Mercedes-Benz Tele Aid system for emergency assistance.
Climate Control:
THERMOTRONIC automatic climate control with multi-zone operation.
Lighting:
Bi-Xenon headlamps with Active Curve Illumination, LED daytime running lights, ambient interior lighting.
Oil Change Interval:
Typically every 10,000-15,000 miles or 12-24 months, depending on driving conditions and specific engine oil used (refer to Flexible Service System - ASSYST PLUS).
Transmission Service Interval:
Mercedes-Benz recommends checking transmission fluid level and condition periodically. Replacement intervals are often based on mileage (e.g., 60,000-80,000 miles) or ASSYST PLUS prompts, but can be debated by independent specialists.
Brake Fluid Change Interval:
Every 2 years
Power Steering Fluid:
MB 345.0 approved hydraulic fluid (often green)
Coolant Capacity:
Approx. 9-10 liters depending on engine
Air Suspension Struts:
Leaking air springs, compressor failures (common on many W221s with AIRMATIC or ABC).
Oil Cooler Seals:
Failure of oil cooler seals leading to coolant leaks into the oil system, potentially causing engine damage (especially on M272/M273 engines).
Intake Manifold Flaps:
Worn or seized intake manifold tumble flaps (M272 engines) can affect performance and cause check engine lights.
Parking Brake:
Malfunctions of the electronic parking brake actuator.
O2 Sensors:
Premature failure of oxygen sensors, leading to emissions issues and reduced fuel economy.
Award Category:
Luxury Sedan Segment
Common Accolades:
Frequently recognized for comfort, quietness, advanced technology, and build quality by automotive journalists and publications like Car and Driver, MotorTrend, and Edmunds.
Manufacturer Standards:
Adheres to Mercedes-Benz's rigorous internal quality and safety standards.
