Diagnostic Method
After the execution criteria are established, calculate the output fluctuation value of front oxygen (A/F) sensor (averaged for the right and left) and output fluctuation value of rear oxygen sensor. Calculate the diagnosis value when the front oxygen (A/F) sensor output fluctuation value is more than specified value. A/F response properties and diagnosis values are parameters for the judgment value.
Judge as NG when the malfunction criteria below are met. Judge as OK if the criteria below are not met.
Judgment Value
MALFUNCTION CRITERIA AND THRESHOLD VALUE REFERENCE
| Malfunction Criteria | Threshold Value |
|---|---|
| Accumulated variation of output voltage of rear oxygen sensor per 32 milliseconds x 4 divided by accumulated variation of lambda of front oxygen (A/F) sensor per 32 milliseconds x 4 | ≥ 20 |
Time Needed for Diagnosis: 30 to 55 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.