Diagnostic Method

Detect the trouble by calculating the response time of the rear oxygen sensor during fuel cut.

Fig 1: Rear Oxygen Sensor During Fuel Cut Graph

Courtesy of SUBARU OF AMERICA, INC.

• Abnormality Judgment 

  Judge as NG when the following conditions are established.

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  Time when rear oxygen sensor voltage changed from 0.5 V to 0.2 V.	> 491 ms

  Time Needed for Diagnosis:  10 seconds

  Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

• Normality Judgment 
  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  Time when rear oxygen sensor voltage changed from 0.5 V to 0.2 V.	≤ 491 ms

  Time Needed for Diagnosis:  10 seconds