Diagnostic Method

Calculate the continuous time from the sticking of sub feedback control amount to rich or lean side and cumulative deviation (sumdelo 2) of rear oxygen sensor voltage and slice level (target voltage).

Judge NG when the malfunction criteria below are completed after 300 seconds have passed continuously.

Fig 1: Threshold Value Table

Courtesy of SUBARU OF AMERICA, INC.

1. Time Needed for Diagnosis: 

   300 seconds

2. Malfunction Indicator Light Illumination: 

   Illuminates when malfunction occurs in 2 continuous driving cycles.

Judge OK and clear the NG when the rear oxygen output is reversed, and during 4 seconds after that, the sub feedback control amount does not stick to rich or lean sides.