This technical guide provides comprehensive service and repair information for a range of iconic Citroën models, including the GS, CX, BX, Xantia, and C5. These vehicles, originating from France, are celebrated for their innovative engineering and distinctive automotive design. This manual aims to cover the diverse technological advancements and model evolutions across these generations, offering insights into their unique features and performance characteristics. The Technical Guide serves as an essential resource for DIY enthusiasts, independent repair shops, and professional technicians. It details general maintenance procedures, troubleshooting common faults, and in-depth engine and transmission service and repair. The manual also covers critical systems such as brakes, electrical systems, suspension, steering, cooling, and fuel systems, along with bodywork and interior components. With clear instructions, diagnostic procedures, and wiring diagrams, this guide empowers users to effectively maintain and repair their vehicles.