The Mazda 3, model code BK, represents the first generation of Mazda's popular compact car, produced from 2003 to 2009, with the 2007 model year being a notable example. This vehicle is renowned for its sporty handling, stylish design, and reliable performance, often praised for its engaging driving dynamics and above-average interior quality. Available in both sedan and hatchback body styles and offered in various trim levels such as i Sport, i Touring, s Sport, s Touring, and s Grand Touring, the Mazda 3 was designed to appeal to youthful buyers and families seeking economical yet spirited transportation. Its engineering, built on the Ford C1 platform, contributed to its solid reputation, including multiple safety accolades like IIHS Top Safety Pick status and a Car and Driver 10Best recognition. This comprehensive workshop service and repair manual is designed to provide detailed guidance for the maintenance, diagnosis, and repair of the Mazda 3 (BK) across all its trims and body styles. It covers a wide array of systems, including engine mechanicals and management, transmissions (manual and automatic), drivetrain, suspension, steering, brakes, and the complete electrical system, from basic components to complex wiring diagrams. The manual includes step-by-step procedures for routine maintenance, detailed troubleshooting charts, diagnostic trouble code interpretation, and specific repair instructions for components and systems. Furthermore, it provides essential technical specifications, torque values, fluid capacities, and information on using diagnostic tools, making it an indispensable resource for owners, mechanics, and technicians aiming to ensure the optimal performance and longevity of their Mazda 3.