Circuit Description

The DTC P0340 Camshaft Position (CMP) Sensor Circuit diagnostic monitors the output of the CMP sensor. The CMP sensor is located in the distributor and consists of a signal generator and a signal rotor. As the signal rotor turns, a magnetic flux from the magnet is applied to the hall element repeatedly. The hall element generates a voltage that is proportional to the magnetic flux. This voltage signal is wave-shaped and is modified into a digital pulse by the comparator and sent to the Powertrain Control Module (PCM). The PCM uses this pulse/revolution signal to determine the engine speed and the position of each cylinder. The PCM uses this signal to control the fuel injectors and the ignition timing.