When downstream O2 sensor signal output is not detected for pre-defined time, ECM sets DTC P0140.
Item | Detecting Condition | Possible Cause | |
DTC Strategy |
•
Signal monitoring | 1. Poor connector connection 2. Short/open in downstream O2 sensor signal circuit 3. Faulty downstream O2 sensor | |
General Enable Condition |
•
30 sec. elapsed after downstream dew point end detected
•
Battery voltage is higher than 11V
•
Exhaust gas temperature around O2 sensor is higher than 350℃(662℉)
•
No downstream O2 sensor heater error | ||
Enable Condition | Case 1 |
•
Time duration for target lambda(1.12) is 12 sec.
•
Lambda feedback control value is at between 0.95 and 1.05 | |
Case 2 |
•
Time duration for target lambda(0.88) is 12 sec.
•
Lambda feedback control value is at between 0.95 and 1.05
•
Osciliation test not completed | ||
Threshold Value | Case 1 |
•
Downstream O2 sensor voltage is higher than 0.65V | |
Case 2 |
•
Downstream O2 sensor voltage is lower than 0.65V | ||
Diagnostic Time |
•
95 sec. | ||
MIL ON Condition |
•
3 driving cycles | ||
