A common rail diesel injection system is a crucial part of modern diesel engines, responsible for delivering high-pressure fuel to the engine’s injectors. In this system, fuel flows from the pre-filter and fuel filter to the high-pressure pump, which increases fuel pressure and sends it to the common rail. From the common rail, fuel is distributed evenly to the injectors. Key components include the rail pressure sensor, PCV valve, throttle pedal, and sensors for the crankshaft and camshaft, all managed by the Powertrain Control Module (PCM). The fuel path is often depicted in diagrams using a yellow line, highlighting the flow of fuel throughout the system.