The 2001 BMW 3 Series, designated by the chassis code E46, represents a significant iteration in BMW's renowned compact executive vehicle line. Building on a heritage of exceptional engineering and driving dynamics, the E46 distinguished itself in the premium segment with its balanced chassis, precise steering, and the availability of potent inline-six engines, including the 2.5L M54B25. This generation offered a compelling blend of performance, comfort, and sophisticated design, directly competing with established luxury brands and frequently earning accolades for its class-leading handling. The 2001 model year signifies a period within the E46's lifecycle that incorporated styling updates and technological advancements, further solidifying its reputation for quality and driver engagement across its various body styles, such as the sedan, coupe, convertible, and touring. This comprehensive factory service repair manual provides in-depth guidance for all mechanical and electrical systems of the 2001 BMW 3 Series (E46). It covers a vast array of components and procedures, including detailed information on engine mechanicals, engine management systems, fuel and cooling systems, transmissions, drivetrain, suspension, steering, brakes, and all aspects of the chassis electrical system. The manual details routine maintenance, scheduled servicing, component removal and installation, diagnostic procedures, troubleshooting, and repair strategies. With its factory-level detail, including color-coded wiring diagrams and special tool identification, this manual is an indispensable resource for professional automotive technicians, service departments, and advanced DIY enthusiasts seeking to maintain, repair, and understand their E46 vehicle.