🏷️ Basic Information Identification Make: BMW Model: 850i Chassis Code: E31 Year: 1991 Codes Product Name: 1991 BMW 850i E31 Wiring Diagram Product Description: BMW 850i E31 Wiring Diagram 👋 Introduction Market Position Positioning: The BMW 850i (E31) was a flagship luxury grand tourer, representing BMW's pinnacle of automotive engineering and design in the early 1990s. Competitive Analysis Competitors: Competed with high-end coupes such as the Mercedes-Benz SEC, Porsche 928, and Jaguar XJS. Key Features Design: Striking 'shark nose' styling, pop-up headlights, pillarless hardtop coupe design. Powertrain: Initially featured the V12 engine, a testament to BMW's engineering prowess. Technology: Advanced for its time, including electronic throttle control, self-leveling headlights, and sophisticated onboard diagnostics. Manual Value Proposition Utility: This wiring diagram manual is indispensable for owners and technicians working on the complex electrical systems of the 1991 BMW 850i E31. Target Audience: Enthusiasts, vintage BMW specialists, and independent repair shops. 📋 Manual Details Coverage Areas Wiring Diagrams: Complete Electrical System Page Count Estimated Pages: High (Detailed Diagrams) Manual Type Type: Wiring Diagram Manual Language Language: English Format Format: PDF on CD 📖 Manual Coverage Systems Covered Engine Management: Full wiring for DME (Digital Motor Electronics), ignition, fuel injection, sensors, actuators. Powertrain Control: Wiring for transmission control (e.g., automatic transmission control unit), shift interlocks. Chassis Electrical: Wiring for lighting (headlights, taillights, interior), wipers, washers, horn, power windows, mirrors, locks. Comfort And Convenience: Wiring for climate control (HVAC), power seats, heated seats, sunroof, central locking, cruise control. Instrumentation: Wiring for instrument cluster (speedometer, tachometer, fuel gauge, temperature gauge), warning lights, OBC (On-Board Computer). Audio And Navigation: Wiring for radio, speakers, antenna, and early navigation systems if applicable. Safety Systems ABS: Wiring for ABS (Anti-lock Braking System) control unit and sensors. Airbags: Wiring for airbag system components (control unit, sensors,SRS warning light). Procedures Included Troubleshooting: Diagnostic routing for electrical faults, component identification. Component Location: Diagrams indicating the location of electrical components and connectors. Connector Pinouts: Detailed pin assignments for various electrical connectors. Fuse And Relay Identification: Identification and location of fuses and relays within the vehicle's electrical system. Technical Depth Level Of Detail: Comprehensive, factory-level detail suitable for professional diagnostics and repairs. Diagnostic Aid: Essential for tracing electrical circuits, identifying shorts, open circuits, and ground faults. 📊 Manual Specifications File Format Format: PDF Searchability: Likely searchable text within the PDF for component names and circuit descriptions. Print Quality Quality: High-resolution scans for clear readability of diagrams. Binding Type Binding: Not Applicable (CD-ROM) Paper Type Type: Not Applicable (CD-ROM) ⚙️ Engine Specifications Primary Engine Engine Code: M70B50 Engine Type: Naturally Aspirated V12 Displacement: 4988 cc (5.0 Liters) Performance Horsepower: 296 hp @ 5200 rpm Torque: 332 lb-ft @ 4100 rpm Fuel System Induction: Multi-point Fuel Injection (Bosch Motronic DME 3.3) Fuel Type: Premium Unleaded Gasoline Cooling System Coolant Type: BMW Blue Long-Life Antifreeze (e.g., BMW Part No. 82 14 9 407 006 or equivalent ethylene glycol based with silicate inhibitors) 🔧 Transmission Standard Transmission Type: 4-speed Automatic (ZF 4HP-24) Optional Transmission Type: 6-speed Manual (Getrag 630G) Features Adaptive Control: Automatic transmission featured adaptive shift logic. Fluid Specification Automatic Transmission Fluid: Dexron III or equivalent (e.g., ZF TE-ML 04D, 14A) Fluid Capacity Automatic Transmission Capacity: Approximately 7.5 Liters (15.8 US quarts) for a complete refill. 📐 Dimensions Exterior Length: 193.5 inches (4915 mm) Width: 71.7 inches (1821 mm) Height: 52.4 inches (1331 mm) Wheelbase: 107.4 inches (2728 mm) Weights Curb Weight: Approx. 4060 lbs (1842 kg) for automatic Gross Vehicle Weight Rating: Approx. 5137 lbs (2330 kg) 🛡️ Safety Features Ratings NHTSA Crash Test: Data not readily available for this era's specific crash test rating format. Active Features ABS: Standard Anti-lock Braking System (ABS). Traction Control: Optional ASC (Automatic Stability Control) available on some models. Passive Features Airbags: Driver and passenger airbags (SRS - Supplemental Restraint System) standard. Seatbelts: 3-point inertia-reel seat belts with pretensioners. 💡 Technology Features Infotainment Audio System: BMW Bavaria C Business RDS or similar high-fidelity sound systems. Driver Assistance Cruise Control: Electronic cruise control. Onboard Computer: BMW On-Board Computer (OBC) providing various vehicle status and trip information. Connectivity Early Systems: While rudimentary by modern standards, early forms of vehicle network communication and diagnostics were present, relying on specific wiring pathways. 🔧 Maintenance Service Intervals Oil Change: Typically every 7,500 - 10,000 miles (12,000 - 16,000 km) or annually, depending on usage and oil type, as indicated by the vehicle's oil service indicator. Major Service Items: Spark plugs (every 60,000 miles), coolant flush (every 2-3 years), transmission fluid and filter service (per manual recommendations, often around 60,000 miles). Fluid Specifications Engine Oil: SAE 5W-30 or 5W-40 synthetic oil meeting BMW Longlife-98 specification or equivalent. Engine Oil Capacity: 7.5 Liters (7.9 US Quarts) Brake Fluid: DOT 4 Low Viscosity (LV) or DOT 5.1 Known Issues Electrical Gremlins: Due to the complexity and age, electrical...