Two CMP sensors are only used on 2006 and earlier models, while four VVT sensors are utilized on 2007 and later models. The camshaft position sensor determines the position of the camshaft for sequential fuel injection to each cylinder, with one sensor located at the end of each cylinder head. A problem in the camshaft sensor circuits will set a diagnostic trouble code. To check the camshaft sensor, disconnect the electrical connector at the sensor and probe the two terminals with an ohmmeter to check the resistance of the camshaft position sensor installed on the cylinder head. Ensure the ignition key is in the OFF position. To access the sensor on the rear cylinder head, remove the fuel injection V-bank cover and the air cleaner hose. Disconnect the harness connector, remove the mounting screws, and take out the camshaft sensors from the cylinder heads. Installation is the reverse of the removal procedure.