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 monitors CAM phaser error while CMP signal is normally generating and vehicle is driving in 2000 ~ 3000rpm
If the CAM phaser does not move although PCM commands OCV duty cycle PCM determines that a fault exists and a DTC is stored.
Item
Detecting Condition
Possible cause
DTC Strategy
? Determines if the phaser is stuck or has steady-state error
? Engine Oil
? OCV stuck
? CVVT stuck
Enable Conditions
? CAM signal is normally generating
? Vehicle is on driving (2000 ~ 3000RPM) for 5 minutes.
Threshold value
Case 1
? 5 CAD < Cam Actual Position < 50 CAD
? Duty Cycle > 90% or Duty Cycle < 10%
Case 2
? Cam Position error > 15 CAD(Difference between Actual Postion and Desire Position is more than 15°)
? Timing Counter > 80
Diagnosis Time
? Continuous (within 5min.)
MIL On Condition
? 2 Driving Cycles