Theory Of Operation

The 3.6L has four separate Camshafts that the Powertrain Control Module (PCM) requires positional information from. There are two Camshaft Position (CMP) Sensors on the 3.6L, each CMP Sensor consists of four circuits. The sensors are located on the top end of each valve cover, closest to the transmission side of the engine. The CMP Sensor is an integrated circuit sensing device and on the end of each Camshaft is a magnetic encoder that is programmed with a magnetic pattern. The PCM provides a 5-Volt supply and a sensor ground circuit to the CMP Sensor and the CMP Sensor provides two Camshaft positional signals, the intake and exhaust camshaft position, to the PCM. The sensor detects the magnetically encoded information, a series of magnetic peaks and valleys, from the encoder. As each Camshaft rotates, the magnetic encoded pattern passes by the CMP Sensor creating a changing magnetic field at the sensor face. The changing magnetic field is interpreted by the sensor electronics and a digital output, ON/OFF or HIGH/LOW pattern, is produced. The length of the pulse widths generated by the CMP varies in size based on the velocity of the Camshaft. The PCM decodes the digital pattern to identify the Camshaft position. The information from each individual Camshaft along with the Crankshaft information is used to control and sequence the Variable Valve Timing (VVT) system and fuel injection events.