Diagnostic Method

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

Fig 1: Rear Oxygen Sensor After 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 0.3 V to 0.5 V.	> 4000 ms

  Time Needed for Diagnosis:  10 seconds

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

• Normality Judgment 

  Judge as OK and clear the NG if the following conditions are established.

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  Time when rear oxygen sensor voltage changed from 0.3 V to 0.5 V.	≤ 4000 ms

  Time Needed for Diagnosis:  10 seconds