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Diagnostic Method

After the execution criterias are established, calculate the output fluctuation value of front oxygen (A/F) sensor and output fluctuation value of rear oxygen sensor. Calculate the diagnosis value when the front oxygen (A/F) sensor output fluctuation value become the specified value or more. A/F response properties and diagnosis values are parameters for the judgment value.

Judge as NG if the criteria below are met. Judge as OK if the criteria below are not met.

Judgment Value 

JUDGMENT VALUE

Malfunction Criteria Threshold Value
Accumulated variation of rear oxygen sensor output voltage per 32 milliseconds divided by lambda accumulated variation of the front oxygen (A/F) sensor per 32 milliseconds ≥ 12

Time Needed for Diagnosis:  30 - 55 seconds

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