The sensors and electrical components on a 2003–2004 5.9L Cummins are essential for monitoring engine performance and communicating with the ECM (Engine Control Module). These parts work together to ensure efficient operation, proper fuel delivery, and emissions control.

Key sensors include the MAP (Manifold Absolute Pressure) sensor, IAT (Intake Air Temperature) sensor, coolant temperature sensor, crankshaft and camshaft position sensors, and oil pressure sensor. They provide real-time data to the ECM, which adjusts timing, fuel injection, and turbo boost accordingly.