🏷️ Basic Information Identification Make: Mercedes-Benz Model: W126 SEC Model Year: 1989 Codes Chassis Code: W126 Body Style Code: C126 (Coupé) 👋 Introduction Market Position Vehicle Segment: Luxury Grand Tourer Coupé Target Audience: Discerning individuals seeking a sophisticated and powerful personal luxury vehicle. Competitive Analysis Key Competitors: BMW 6 Series (E24), Jaguar XJ-SC, Aston Martin Virage. Key Features Vehicle Attributes: Elegant styling, powerful V8 engines, high-quality interior appointments, advanced engineering for its time, comfortable ride. Manual Utility Benefit For Owner: Empowers owners to perform maintenance and repairs accurately, reducing reliance on external service providers and preserving vehicle value. Accuracy Claim: Exact manual used by dealership technicians, ensuring vehicle-specific accuracy. 📋 Manual Details Coverage Areas Primary Coverage: 1989 Mercedes-Benz W126 SEC Coupé Model Variants Covered: All 1989 W126 SEC models, including all engine and trim variations specific to the 1989 model year. Page Count Estimated Page Count: Likely 800-1200 pages (typical for comprehensive factory service manuals of this era, though exact count not provided). Manual Type Type: Factory Service and Repair Manual Language Language: English Format Format: Digital (PDF) 📖 Manual Coverage Systems Covered Engine Systems: Engine mechanical, fuel system, ignition system, lubrication, cooling system, emission control, intake and exhaust. Transmission Systems: Automatic transmission (likely 4-speed 722.3/722.4 for SEC models), clutch (where applicable for auxiliary systems), manual transmission (unlikely for SEC, but listed as potential coverage if any variations exist). Drivetrain Systems: Transfer case/propeller shaft, drive shafts, differential, axle suspension, wheels and tires. Brake Systems: Brake control, hydraulic braking system, parking brake. Steering Systems: Steering column, power steering. Electrical Systems: Starting and charging system, lighting, instrumentation, power windows, central locking, power seats, power mirrors, cruise control, wipers/washers, horn, multiplex/CAN communication (early forms). Climate Control Systems: Air conditioning system, heating. Body And Interior Systems: Engine hood/doors, exterior trim, interior trim, seats, windshield/glass/mirrors, instrument panel, supplementary restraint system (SRS - airbags, seatbelt pre-tensioners), seat belts. Safety And Security Systems: Engine immobilizer (if equipped), supplementary restraint system (SRS), seat belts, door locks. Procedures Included Maintenance Procedures: Scheduled maintenance, fluid level checks, filter replacements, lubrication, tune-ups, pre-delivery inspections (PDI). Diagnostic Procedures: Troubleshooting guides, diagnostic flowcharts, identification of common faults, specific component testing procedures. Repair Procedures: Step-by-step instructions for component removal, disassembly, repair, reassembly, and installation for all covered systems. Electrical Repair Procedures: Wiring schematic interpretation, component testing, troubleshooting electrical circuits, connector diagnosis. Specification Data: Torque specifications, clearances, tolerances, fluid capacities, pressure specifications, electrical resistance values. Technical Depth Depth: Factory-level, comprehensive A-Z coverage for all repairs and maintenance. Detail Level: High detail with step-by-step instructions, diagrams, illustrations, and wiring schematics. 📊 Manual Specifications File Format File Type: PDF Readability: Searchable text (typical for professional PDFs), allows zooming for detail. Print Quality Printability: Fully printable, allowing users to print specific sections or diagrams as needed. Binding Type Binding: Digital (no physical binding) Paper Type Paper Quality Simulated: Printable on any standard paper; original factory manuals were printed on high-quality paper stock. ⚙️ Engine Specifications Primary Engine Engine Type: M117 V8 (SOHC) Displacement: 5.0 Liters (M117.968) Performance Horsepower: Approximately 238 hp (DIN) @ 4750 rpm (for 500 SEC, European spec; US spec may vary slightly due to emissions). Torque: Approximately 405 Nm (299 lb-ft) @ 2750 rpm (for 500 SEC, European spec). Fuel System Fuel Delivery: Bosch KE-Jetronic (CIS-E) Fuel Injection (K-Jetronic with electronic control). Fuel Type: Unleaded Premium Gasoline (91+ octane recommended). Cooling System Coolant Type: Mercedes-Benz specification coolant (e.g., MB 325.0 / G48, typically a glycol-based antifreeze with corrosion inhibitors). Lubrication System Oil Type: API SG or higher, SAE 10W-40 or 10W-30 (depending on climate, consult manual for precise W126 specifications). Maintenance Oil Change Interval: Typically 10,000 km or 6,000 miles / 12 months, whichever comes first (consult manual for exact interval). 🔧 Transmission Standard Type: 4-speed Automatic Transmission Model Code: 722.3XX or 722.4XX (e.g., 722.364 for 500 SEC). Features Control: Hydraulic control with electronic feedback (KÜMBA system). Fluid Specifications Fluid Type: MB 236.1 specification Automatic Transmission Fluid (ATF), typically Dexron IIE or equivalent approved fluid. Maintenance Fluid Change Interval: Typically 50,000 km or 30,000 miles (consult manual for exact interval). 📐 Dimensions Exterior Length: Approx. 4960 mm (195.3 in) Width: Approx. 1798 mm (70.8 in) Height: Approx. 1387 mm (54.6 in) Weights Curb Weight: Approx. 1750 - 1850 kg (3858 - 4079 lbs), depending on equipment. 🛡️ Safety Features Ratings Crash Safety Design: Designed with advanced crumple zones and safety cage for its era. Active Features Brake System: Anti-lock Braking System (ABS) - standard on SEC models. Passive Features Airbags: Driver-side airbag was becoming standard or optional around this period; manual will detail its presence and servicing. Seat Belts: Front and rear seat belts, potentially with pre-tensioners depending on specific US vs. European market configuration for 1989. 💡 Technology Features Infotainment Audio System: Factory fitted premium sound system, potentially with cassette player and external amplifier....