Diagnostic Method
When the oxygen sensor output voltage changes from 0.55 V (rich) to 0.25 V (lean), calculate the Min. value of response time regarded as judgment value while the output varies from 0.5 V to 0.3 V.
- Abnormality Judgment
- Judge NG when the judgment value is larger than the threshold value after fuel shut-off in deceleration. Response time (Diagnosis value) > Threshold value --> AbnormalNOTE: Variation time of rear oxygen sensor output voltage is short during fuel shut-off in deceleration. Carry out the NG judgment only after the fuel shut-off in deceleration. As for OK judgment, without the condition of fuel shut-off in deceleration, judge OK if the value is below the threshold value.
Judge NG when the malfunction criteria below are completed in 2 seconds after the recovery of fuel shut-off in deceleration which requires 6 seconds or more. - Judge NG when the oxygen sensor voltage after recovery of fuel shut-off in deceleration is large. Judge NG when fuel shut-off in deceleration is also long (6s or more), and although carried out the fuel shut-off in deceleration cut return, when oxygen sensor voltage is large (more than 0.55 V).
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Shortest time change from rich (500 mV O2 output) to lean (300 mV) if voltage reduces from 550 mV to 250 mV. | 0.327 milliseconds |
| Time when more than 550 mV | > 2 seconds |
Time Needed for Diagnosis: 1 time
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
- Normality Judgement
- Judge Normal when the response time (diagnostic value) is smaller than threshold (judgment value) when changing to lean since oxygen sensor voltage.
- A normal judging is not carried out.
Judgment Value
Judge OK when the following standards value are completed.
| Malfunction Criteria | Threshold Value |
|---|---|
| Change of the shortest time from rich (500 mV02 output), when voltage decreases from 550 mV to 250 mV to lean (300 mV). | </= 0.327 seconds |
When the oxygen sensor output voltage changes from 0.25 V (lean) to 0.55 V (rich), calculate the Min. value of response time regarded as judgment value while the output varies from 0.3 V to 0.5 V.
- Abnormality Judgment
- Judge NG when the judgment value is larger than the threshold value after recovery of fuel shut-off in deceleration.
Response time (Diagnosis value) > Threshold value --> Abnormal
- Judge NG when the oxygen sensor voltage after recovery of fuel shut-off in deceleration is small.
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Shortest time change from lean (300 mV O2 output) to rich (500 mV) if voltage reduces from 500 mV to 250 mV. | > 2 seconds |
| Time when less than 250 mV | > 100 seconds |
Time Needed for Diagnosis: 1 time
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
- Normality Judgement
- Judge Normal when the response time (diagnostic value) is smaller than threshold (judgment value) when changing to lean since oxygen sensor voltage.
Response Time (diagnosis value) </= Threshold value --> Normal
- A normal judging is not carried out.
Judgment Value
Judge OK when the following standards value are completed.
| Malfunction Criteria | Threshold Value |
|---|---|
| Change of the shortest time from rich (300 mV02 output), when voltage decreases from 550 mV to 250 mV to lean (500 mV). | </= 2 seconds |