Diagnosis Method 3 (Mt Model Only)

Change STFT (A/F compensation value) by interruption, and measure the reaction time of λ value. When A/F sensor malfunctions, the reaction time takes longer than at normal condition. In this case, judge as abnormal.

Fig 1: STFT And Sensor Output Graph (Diagnostic Method 3, MT Model Only)

Courtesy of SUBARU OF AMERICA, INC.

Measure reaction time (t1, t2, t3) and reaction time (t4, t5, t6). Use the average value of the reaction time to obtain the diagnostic value.

Fig 2: STFT And Sensor Reaction Time Graph

Courtesy of SUBARU OF AMERICA, INC.

Abnormality Judgment

Judge as NG when the following conditions are established.

JUDGMENT VALUE

Malfunction Criteria	Threshold Value	DTC
(t1 + t2 + t3)/3	> 820 ms (except for PZEV model)	P015A and P015B
	> 800 ms (PZEV model)
and
(t4 + t5 + t6)/3	> 820 ms (except for PZEV model)
	> 800 ms (PZEV model)

Time Needed for Diagnosis: 1000 ms x [1 time(s)/2] + 1000 ms x 3 time(s) + 500 ms

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

Malfunction Criteria	Threshold Value	DTC
(t1 + t2 + t3)/3	≤ 820 ms (except for PZEV model)	P015A and P015B
	≤ 800 ms (PZEV model)
or
(t4 + t5 + t6)/3	≤ 820 ms (except for PZEV model)
	≤ 800 ms (PZEV model)

Time Needed for Diagnosis: 1000 ms x [1 time(s)/2] + 1000 ms x 3 time(s) + 500 ms