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 ECM detects short to power in OCV(Bank 2-EX) control circuit, ECM sets DTC P0086.
Item
Detecting Condition
Possible Cause
DTC Strategy
Power stage diagnosis(Exhaust)
Poor Connection
Short to battery in control circuit
OCV
Enable Conditions
-
Threshold value
Short circuit to battery
Diagnosis Time
Continuous
MIL On Condition
NO MIL
Specification
Resistance (?)
6.7 ~ 7.7 at 20?(68?)
Fig.1) Normal waveform of OCV at idle.
Fig.2) Normal waveform of OCV at acceleration.