P0140

DTC P0140 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK1 SENSOR2)

1. OUTLINE OF DIAGNOSIS
Detect abnormalities in the rear oxygen sensor output characteristics.

By referring to the intake air amount, engine coolant temperature, main feedback control, deceleration fuel cut and other operating conditions, if the rear oxygen sensor voltage should be moving under these conditions but is showing a low voltage, this is judged as a Low side NG. If the voltage is showing a high voltage, it is judged as a High side NG.

When either Low side or High side is NG, judged as rear oxygen sensor property NG.




2. ENABLE CONDITION

3. GENERAL DRIVING CYCLE
Perform the diagnosis only once after engine warm- up.

4. DIAGNOSTIC METHOD




Abnormality Judgment
When one of the following conditions is established, judged as NG.




Normality Judgment
When the following conditions are established, judged as OK.

5. DTC CLEAR CONDITION
- When the OK idling cycle is completed 40 times in a row
- When "Clear Memory" is performed

6. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle is completed 3 times in a row
- When "Clear Memory" is performed

7. FAIL SAFE
Sub feedback control: Not allowed.

8. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)