The CVVT (Continuously Variable Valve Timing) system is installed to the chain sprocket of the intake camshaft. This system controls the intake camshaft to provide the optimal valve timing for every driving condition. The ECM controls the Oil Control Valve(OCV), based on the signals output from mass air flow, throttle position and engine coolant temperature. The CVVT controller regulates the intake camshaft angle using oil pressure through the OCV. As result, the relative position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, exhaust emissions decrease under overall driving conditions.
If there is a delay between the target angle and the real angle over 5 times,ECM sets DTC P0014.
Item
Detecting Condition
Possible Cause
DTC Strategy
Slow response check
Poor connection
Contamination of Oil / Clog of Oil path
OCV
CVVT
Enable Conditions
Time after | target VVT angle –VVT angle | > 6 deg(2 sec)
Time after engine start > 10 ~ 60 sec
Engine oil temperature : 32~266?(0~130?)
1000 < rpm < 6600rpm
Threshold value
Counter of delayed following target valve timing > 5 times
Diagnosis Time
-
MIL On Condition
2 Driving Cycles
Specification
Coil Resistance (?)
6.7 ~ 7.7 (20?)
Fig.1) Normal waveform of OCV & EX-CMPS at idle.
Fig.2) Normal waveform of OCV & EX-CMPS at acceleration with load.