Outline Of Diagnosis

Detect NG when having either Low NG or High NG.

A variable valve lift diagnosis oil pressure switch is installed for diagnosis. It is possible to determine whether the intake valve is in high mode (increase the amount of lift) or in low mode (suppressing the amount of lift) when the variable valve lift diagnosis oil pressure switch is turned ON or OFF.

• Normal 
  OIL PRESSURE SWITCH POSITION CHART - NORMAL
  
  

  Oil switching solenoid valve duty	Intake valve	Variable valve lift diagnosis oil pressure switch
  Large	High mode	ON
  Minimum	Low mode	OFF

• Low NG 

  When the variable valve lift diagnosis oil pressure switch remains OFF even though the intake valve tried to enter high mode (oil switching solenoid valve duty is large), this is judged as a Low NG.

• High NG 

  When the variable valve lift diagnosis oil pressure switch remains ON even though the intake valve tried to enter low mode (oil switching solenoid valve duty is small), this is judged as a High NG.