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.
The deviation of the camshaft position from the target point is evaluated during stable driving condition. The PCM accumulates this deviation for a certain period and sets DTC P0011 when the accumulated deviation is too high. The target camshaft position is predetermined value depending on engine speed and throttle angle in the PCM.
Item
Detecting Condition
Possible Cause
DTC
Strategy
case1
Monitor deviation between camshaft position setpoint and actual value
Faulty Oil leak
Faulty Oil pump
Faulty Intake valve control solenoid
case2
Deviation between actual CAM position and CAM setpoint position in case of changing setpoint (slow response of actuator)
Enable
Conditions
No relevant failure
11V < Battery voltage < 16V
CVVT control : enabled
Holding position adaptation not active
Camshaft setpoint moved more than 5 times for this Driving Cycle
Stable camshaft set-point moving by more than 1.125°CRK moving
Camshaft position setpoint-actual > 5°CRK
600rpm < Engine speed < 5000rpm
20?(68?) < Engine oil temperature < 100?(212?)
CVVT control active
Camshaft set-point moving by more than 20°CRK
Camshaft set-point moved more than 5 times since engine start
600 rpm < Engine speed < 5000 rpm
20 ?(68?) < Oil temperature < 110 ?(230?)
Threshold Value
Integral of Camshaft position setpoint - Camshaft position actual value > 150°CRK/sec.
CAM position movement < 2.6 °CRK within 0.7 sec. (with CAM set-point moving by 20 °CRK)
Diagnostic Time
Approx. 38~300 seconds depending on CAM deviation
350 sec.
Mil On Condition
2 Driving Cycles
Intake OCV
Normal Parameter
Insulation Resistance (?)
Above 50 ?
Fig.1) Normal OCV (-) duty ratio with idle : Approx. 12~20%
Fig.2) Normal OCV (-) duty ratio with maintaining 2000RPM : Approx. 30~50%