From models manufactured in 2001, Variable Valve Timing (VVT) is incorporated in the assembly, with the control valve being affiliated to the oil system, the oil filter, or the intake
Camshaft sprocket/actuator of either cylinder head. The VVT system controls intake camshaft position by regulating the pressure of oil to improve torque, fuel consumption, exhaust emission. Part include PCM; the Oil control valves (OCVs); the oil filters; the intake camshaft sprocket/actuator. The PCM expends signal data from different sensors to regulate the OCV, which disseminates oil pressure to modify the position of the camshaft. Within the sprocket/actuator assembly, there is an internal hub with set vanes which is rotated with the help of oil pressure for the adjustment of up to 21°. In different loads of the engine, the system changes the camshaft timing to increase performance and more efficiency. Problems in the VVT system arise from the OCVs and filters requiring service often. Occasionally, certain OCV filters become clogged which can cause issues, that means the filter needs to be checked and preferably cleaned. It is necessary to check the OCV, for doing this you must measure the resistance across its terminals; if the value is out of the range it should be replaced. For replacement, unplug the electrical connector, and unscrew the hold-down bolt in addition to installing a new O-ring. The camshaft sprocket/actuator assembly thus needs to be well handled, s accepting that it must remain locked at idle conditions. Relatively, the advance side oil port if cleaned and subjected to air pressure, the actuator should move freely; if it fails to do so, replacement is mandatory. In case of replacing the assembly, make sure that the lock pin is aligned to the groove, lubricate the seating plane to the assembly, and use a new retaining nut which is retailed to be turned in the opposite direction. Last but not the least, replace back the intake camshaft, timing belt and finally the valve cover.