Camshaft Position Sensor
The Camshaft Position Sensor (CMP) is mounted to the rear of the cylinder head. See Fig 1 or Fig 2 . The CMP sensor also acts as a thrust plate to control camshaft endplay. The PCM sends approximately 8 volts to the Hall Effect sensor. This voltage is required to operate the Hall Effect chip and the electronics inside the sensor. A ground for the sensor is provided through the sensor return circuit. The input to the PCM occurs on a 5-volt output reference circuit. A target magnet attaches to the rear of the camshaft and indexes to the correct position. See Fig 3 . The target magnet has four different poles arranged in an asymmetrical pattern. As the target magnet rotates, the CMP sensor senses the change in polarity. See Fig 4 . The sensor output switch switches from high (5.0 volts) to low (0.5 volt) as the target magnet rotates. When the north pole of the target magnet passes under the sensor, the output switches high. The sensor output switches low when the south pole of the target magnet passes underneath.