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.
When the enable condition is satisfied The PCM checks that high and low outputs (Voltage level) are observed when OCVs are commanded. When a OCV output failure is detected, the appropriate fail counter is incremented.
If the failure threshold is exceeded 5 seconds during one diagnostic test(10 second), the test is failed and DTC is stored. MIL(Malfunction Indicatin Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● Detects a short to ground or open | ● Poor Connection ● Open in Power Circuit ● Open or short to ground in control circuit ● OCV ● PCM |
Enable Conditions | ● No disabling Faults Present ● Engine Running ● 11V ≤ Ignition Voltage ≤ 16V | |
Threshold value | ● Short to ground or open circuit | |
Diagnosis Time | ● Continuous (More than 5 seconds failure for every 10 seconds test ) | |
MIL On Condition | ● 2 Driving Cycles |
Resistance (Ω) | 6.7 ~ 7.7 at 20℃(68℉) |
