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 PCM 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.
PCM detects CAM phasing average rate while cam offset is available. If the CAM phasing rate is failure in 12 times out of 15 CAM phasing test PCM determines that a fault exists and a DTC is stored.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● Determines if the phaser is moving at an expected rate | ● Excessive phasing system leakage ● Insufficient Oil Pressure (ex. Blockage in OCV filter) ● Faulty PCM |
Enable Conditions | ● Cam Offset is available | |
Threshold value | ● Cam phasing average rate is out of threshold programmed in PCM | |
Diagnosis Time | ● Continuous (12 tests failure for 15 cam edge tests) | |
MIL On Condition | ● 2 driving cycles |
