The Variable Valve Timing-intelligent (VVT-i) system is installed in all models; it varies the intake camshaft timing with V6 models ranging from 0 to 50 degrees and four-cylinder engines ranging from 0 to 35 degrees, depending with the driving condition. This system works with the help of the pressure of the engine oil for controlling the major part of the controller that is installed on the intake camshaft. For V6 models there are Two VVT-i sensors, Powertrain Control Module (PCM), Two oil control valves and Two actuator assembly while for the four-cylinder models there is CMP sensor, One oil control valve and One actuator. The elements included in the design of each V6 controller are a timing rotor, an impeller-type vane housing assembly, a lock pin, and a timing chain sprocket. Oil pressure controls the rotation of the vane and change the position of the valve. During the OFF state, the intake cam is positioned in a retarded manner to facilitate easier engine starting mechanism and a lock pin removes noise until oil is pumped into it. The operation entails the altering of the position of the camshaft in relation to the oil flow, while the PCM regulates the oil control valves in accordance with the load on the engine. The camshaft position actuator, which is commanded by the PCM, is an electrically-controlled solenoid that regulates the flow of oil to the desirable passages; a spring-loaded spool valve controls the flow of oil based on the engine's speed. For the V6 models, now are two VVT sensors mounted on the cylinder head, and its replacement is done by disconnecting the battery, removing the engine cover and air filter housing, and then accessing the sensors. On the camshaft timing oil control valve the same procedure is performed with the only additional intervention being related to electrical connection, which is disconnected along with the removal of the mounting bolt. Regarding the four-cylinder models, you require disconnecting the electrical connectors and, consequently, the mentioned mounting bolts, which can be used for
Camshaft Position Sensor and timing oil control valve removing and, in its turn, the installation is conducted pursuant to the described above removal process.