When the sensor output is out of specification under enable condition, ECM sets DTC P0138 and turns the MIL on.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Signal monitoring | 1. Poor connector connection 2. Short to power 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 |
•
- | |
Threshold Value |
•
Downstream O2 sensor voltage is higher than 1.15V | |
Diagnosis Time |
•
5 sec. | |
MIL ON Condition |
•
3 driving cycles |