Different from the existing fixed cam phase angle type, CVVT(Continuously Variable Valve Timing) is the device which varies cam phase angle continuously to be optimum. And with engine oil pressure, it operates. CVVT consists of OCV(Oil Control Valve) and cam phaser. OCV, mounted on cylinder head, controlls the amount and direction of oil delivered to cam phaser by oil valve which is connected to a solenoid. Cam phaser, rotating cam phaser rotor with pressure and amount of oil produced by OCV, rotates cam shaft forcefully for or against the rotating direction and finally, cam shaft phase changes. With the appliance of CVVT, engine power,fuel efficiency and the quality of exhaust gas are improved.
When ECM detects short to power in OCV control circuit, ECM sets DTC P0077.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Circuit continuity check, high | 1. Poor connection 2. Short to battery in control circuit 3. OCV |
Enable Conditions |
•
Coolant temperature > -5℃
•
Time after engine start > 3.5s | |
Threshold Value |
•
Short circuit to battery | |
Diagnostic Time |
•
Continuous | |
MIL ON Condition |
•
3 driving cycle |
Item | Specification |
Coil Resistance (Ω) | 6.9 ~ 7.9 [20 ℃ 68 ℉] |
The ECM controls OCV by duty value.
