This manual covers the 3 Series (E46) models produced between 1999 and 2005. Known for embodying a driving philosophy, the E46 is celebrated for its refined engineering, engaging driving dynamics, and robust performance. This generation introduced significant advancements over its predecessor, solidifying its position in the premium compact executive segment and earning multiple "10Best" awards. The vehicle is available in various body styles, including Sedan, Coupe, Convertible, and Wagon, and is powered by a range of engines, from the 1.9L M43TU to the potent 3.0L M54 and the high-performance S54 found in the M3 variants. This comprehensive service and repair manual provides detailed information for all major mechanical and electrical systems of the 3 Series E46. It covers engine mechanicals, cooling and lubrication systems, fuel injection, ignition, emission control, and diagnostics for engines such as the M52TU and M54. The manual also details transmission overhaul for both Getrag manual and ZF automatic gearboxes, drivetrain components, chassis systems including suspension and brakes, and the complete electrical system with wiring diagrams. It includes step-by-step maintenance procedures, troubleshooting guides for common issues, and in-depth repair instructions, making it an invaluable resource for DIY enthusiasts, independent mechanics, and professional technicians.