The 2003 Subaru Legacy Service Repair Manual is a comprehensive guide designed for Subaru service professionals, providing detailed information and procedures for maintaining and repairing 2003 Subaru Legacy vehicles. This manual encompasses a vast array of topics, covering everything from routine maintenance to intricate component repairs and diagnostics. The manual's General Information section sets the stage with essential information, including a foreword, instructions on using the manual, detailed vehicle specifications, important safety precautions, notes for clarity, vehicle identification procedures, recommended materials, pre-delivery inspection guidelines, and a comprehensive periodical maintenance schedule. The Engine sections delve into the intricate workings of three engine variants – the H4SO, H6DO, and H4DOSTC. These sections provide detailed information on fuel injection systems, emission control systems, intake and exhaust systems, mechanical components, cooling systems, lubrication systems, speed control systems, ignition systems, starting/charging systems, and thorough engine diagnostics. The Transmission section covers both automatic and manual transmissions, addressing control systems, detailed diagnostics, manual transmission and differential operations, and the clutch system. The Chassis section focuses on the vehicle's underpinnings, offering comprehensive information on front and rear suspensions, wheel and tire systems, differentials, transfer cases, drive shaft systems, Anti-lock Braking Systems (ABS), Vehicle Dynamics Control (VDS), braking systems, parking brakes, power-assisted systems, and in-depth diagnostics for both ABS and VDS systems. The Body section dives into the vehicle's structure and associated systems, encompassing HVAC systems, airbag systems, seat belt systems, lighting systems, wiper and washer systems, entertainment and communication systems, glass, windows, and mirrors, body structure, instrumentation and driver information displays, seats, security and locking systems, sunroofs, T-tops, convertible tops, exterior and interior trim, exterior body panels, cruise control systems, and immobiliser diagnostics. Finally, the Wiring System section provides detailed information on the vehicle's electrical system, offering comprehensive diagrams and explanations of the intricate wiring configurations.

The 2003 Subaru Legacy is a mid-size sedan and wagon produced by the Japanese automaker Subaru from 2002 to 2004. It represented the fourth generation of the Legacy line, a model known for its all-wheel-drive capability, rugged construction, and reliable performance. The 2003 Legacy saw a significant redesign from its predecessor, featuring a more rounded, aerodynamic body style with a larger grille and a prominent hood scoop on the higher-trim GT models. Inside, the cabin offered spacious interiors with comfortable seating and a user-friendly dashboard design. Under the hood, the 2003 Legacy came equipped with a range of engine options, including the 2.5-liter naturally aspirated four-cylinder engine, a more powerful 2.5-liter turbocharged four-cylinder engine, and a 3.0-liter naturally aspirated six-cylinder engine. All engines were mated to either a five-speed manual transmission or a four-speed automatic transmission with Subaru's renowned symmetrical all-wheel-drive system. The Legacy's versatile drivetrain, combined with its independent suspension and precise steering, provided a comfortable and capable ride on both paved roads and unpaved surfaces. Its reputation for reliability and durability, coupled with its spacious interiors and distinctive styling, made the 2003 Subaru Legacy a popular choice among car buyers seeking a dependable and practical vehicle.