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. The CVVT controller regulates the intake camshaft angle using oil pressure through the OCV(Oil Control Valve). As result, the relative position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, exhaust emissions decrease 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.
Item
Detecting Condition
Possible Cause
DTC Strategy
Check Camshaft Signal Switching
Abnormal installation of camshaft
Abnormal installation of crankshaft
Abnormal installation of tone wheel
Enable Conditions
6V < Battery voltage < 16V
CVVT control state : Full retard postion or Control
Threshold Value
Camshaft switching out of 109 ~ 141° CRK in full retard position, 70° ~ 140° CRK during CVVT control
Diagnostic Time
8 Sec.
Mil On Condition
2 Driving Cycles
Fig.1) The square wave signal should be smooth and without any distortion.
Fig.2)The CMPS falling(rising) edge is coincided with 3rd~5th tooth of the CKP from one longer signal(missing tooth)