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 - Diagnostic Method

Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria	Threshold Value
Time needed for rear oxygen sensor voltage to change from 0.5 V to 0.2 V	> 837 ms

Time needed for diagnosis: 5 seconds

Malfunction indicator light illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.