This comprehensive troubleshooting manual is specifically designed for the 1991 BMW 850i (E31) model. It is your essential guide to understanding and resolving electrical issues within your vehicle. The manual features a detailed index that provides quick access to critical information. You'll find an introduction outlining the scope of the manual and a comprehensive symbol guide to help you interpret the diagrams and instructions.

The manual dives into the specifics of electrical systems, starting with a power distribution chart, fuse charts, fuse details, and ground distribution maps. This allows you to trace the flow of electricity and identify potential points of failure. It also covers the data link system, crucial for understanding and troubleshooting electronic components.

The manual then focuses on key electrical systems like the engine control system, charging system, start system, electronic transmission control, supplement restraint system, slip control ABS, power mirrors, central locking module, power windows, power seats, heated seats, power sunroof, horn, wiper/washer module, headlight washer, and windshield washer jet heaters.

Moving onto the interior and lighting systems, the manual offers a thorough breakdown of the instrument cluster, multi-function clock, light switch details, headlights/fog lights, turn hazard lights, park/tail/underhood lights, license plate/luggage compartment lights, backup lights, brake lights, interior lights, glove box light/cassette box/ashtray lights/charging socket, crash control module, park/ventilation with HKR, rear window defogger, integrated climate regulation, radio/CD player, radio/hi-fi, cellular telephone, cruise control (Tempomat), anti-theft system, and on-board computer.

The manual concludes with a component location chart, component location views, splice location views, and connector views, allowing you to easily identify and locate specific electrical components within your vehicle. This detailed information significantly simplifies the process of diagnosing and repairing electrical problems in your 1991 BMW 850i (E31).

The BMW 850i (E31) is a luxurious grand tourer produced by BMW from 1989 to 1999. It was the flagship model of BMW's lineup at the time, known for its elegant styling, powerful engine, and advanced technology. The 850i was designed to compete with other high-end grand tourers like the Mercedes-Benz S-Class Coupe and the Jaguar XJS. It featured a sleek, aerodynamic body with a low-slung profile, a spacious and luxurious interior, and a powerful 5.0-liter V12 engine producing 300 horsepower. The 850i was also notable for its advanced technological features, including a four-wheel independent suspension, anti-lock brakes, traction control, and an optional electronic stability control system.

While the 850i was a technological marvel for its time, its complex electrical system can present challenges for owners and technicians. This electrical troubleshooting manual is designed to assist with diagnosing and resolving electrical issues commonly encountered in the BMW 850i (E31). It covers a wide range of electrical components, including the engine management system, the lighting system, the climate control system, and the various electronic modules and sensors. This manual provides detailed information about each component's operation, troubleshooting procedures, wiring diagrams, and common fault codes. The information is presented in a clear and concise manner, with step-by-step instructions and diagrams to guide users through the troubleshooting process. With the help of this manual, owners and technicians can confidently diagnose and repair electrical problems in the BMW 850i (E31) and ensure its continued smooth operation.