Diagnostic Method

After the enable conditions have been established, calculate the front oxygen (A/F) sensor lambda value deviation sum value (Σ |(sglmd_n - sglmd_n-1 )|), and rear oxygen sensor output voltage deviation sum value (Σ|(ro2sad_n - ro2sad_n-1 )|) in every 32 ms x 4 times. If the front oxygen (A/F) sensor lambda value deviation sum value (Σ |(sglmd_n - sglmd_n-1 )|) is the predetermined value or more, calculate the judgment value.

Abnormality Judgment

If the duration of time while the following conditions are met is within the time indicated, judge as NG.

JUDGMENT VALUE CHART

Malfunction Criteria	Threshold Value
Σ \|(ro2sad_n - ro2sad_n-1 )\| / Σ \|(sglmd_n - sglmd_n-1 )\|	> 11 (PZEV model) > 19.5 (AT model except for PZEV) > 16 (MT model except for PZEV)

Time Needed for Diagnosis: 30 - 55 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 continuous time while the following conditions are established is within the predetermined time.

JUDGMENT VALUE CHART

Malfunction Criteria	Threshold Value
Σ \|(ro2sad_n - ro2sad_n-1 )\| / Σ \|(sglmd_n - sglmd_n-1 )\|	≤ 11 (PZEV model) ≤ 19.5 (AT model except for PZEV) ≤ 16 (MT model except for PZEV)

Time Needed for Diagnosis: 30 - 55 seconds