This manual covers the Mitsubishi Eclipse and Eclipse Spyder, produced during the Third Generation (3G) era, specifically focusing on the 2003 model year. These vehicles, assembled in Normal, Illinois for the North American market, represent Mitsubishi's entry into the compact sports coupe and convertible segment, competing with models like the Honda Civic Si and Toyota Celica. The Eclipse and Eclipse Spyder are characterized by their sporty styling and front-wheel-drive platform, offering accessible performance with engine options including a 2.4L 4G64 SOHC, a 3.0L 6G72 SOHC V6, and a potent 3.0L 6G72-T Twin-Turbocharged V6 for GT models. They feature a 4-seat configuration, with distinct trunk volumes for the coupe and Spyder variants. This comprehensive factory service repair workshop manual, written in English, is designed to be an indispensable resource for owners, mechanics, and technicians. It details maintenance procedures, troubleshooting guides, technical specifications, and safety guidelines essential for the upkeep and repair of the Mitsubishi Eclipse and Eclipse Spyder. The manual covers all major systems, including the engine (2.4L 4G64 and 3.0L 6G72 V6 variants), transmissions (5-speed manual and 4-speed automatic), brakes, suspension, electrical systems, fuel and cooling systems, HVAC, interior components, and body and frame. With factory-level detail, including exploded views, torque specifications, and wiring diagrams, this manual provides step-by-step instructions for disassembly, reassembly, diagnostics, and repair.