This engine speed sensor monitors the rotational speed of the engine crankshaft or camshaft and sends the signal to the engine control unit. It is mounted on the engine block, typically near the flywheel or timing gear. The sensor uses a magnetic or Hall-effect element to detect passing ferrous teeth on a target wheel; the resulting pulse train allows the ECU to calculate engine RPM and synchronize fuel injection timing. A failing sensor produces intermittent or no tachometer reading, may cause hard starting, and can trigger fault codes for a missing or implausible speed signal. As an original AGCO-manufactured component, the sensor body and tip geometry match the original housing bore and air gap specification, so no shimming or adapter is required during installation. Clean the mounting surface and apply the specified torque to the retaining bolt on reinstall.