The CVVT (Continuously Variable Valve Timing) system is installed to the chain sprocket of the exhaust camshaft. There is no variation in valve timing of the exhaust cam because the exhaust camshaft is driven by the timing belt. The timing of the intake cam is varied by the relative operation the CVVT vane to the housing. This system helps the engine decrease exhaust gases and increase engine power and fuel economy by changing the valve open / close timing of the intake camshaft.

This diagnosis checks the camshaft position plausibility whether the expected range plus some margin is not violated that might be caused by a wrong engine repair, or a chain/belt misalignment. DTC P0016 is set when actual camshaft position is too much retarded or advanced than full retard position or full advance position. To continue the adjustment in such case could lead to a damage of the engine by hitting the valves with the piston.