Component Location
General Description
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(intake advance/exhaust retard) or against(intake retard/exhaust advance) 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.
DTC Description
When ECM detects short to power in OCV(Exhaust) control circuit, ECM sets DTC P0077.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Circuit continuity check, high.
| Poor connection. Short to battery in control circuit. OCV (Exhaust) |
Enable Conditions | -
|
Threshold Value | Short circuit to battery.
|
Diagnostic Time | Continuous.
|
MIL ON Condition | 3 driving cycle.
|
Specification
Item | Specification |
Coil Resistance (O) | 6.9 ~ 7.9 [20 ? 68 ?] |
Diagnostic Circuit Diagram
Signal Waveform & Data
Fig.1) Normal waveform of OCV at idle.