If the sensor output signal is over 1.08 V under enable conditions, ECM/PCM sets DTC P0138.
(This DTC might be caused by the malfunction of Heater circuit, so, check the heater circuit first.)
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Signal check, high | 1. Poor connection 2. Short to power in signal circuit 3. HO2S(S2) |
Enable Conditions |
•
Dew point end detected
•
Battery voltage is higher than 11V
•
Exhaust Gas temperature is higher than 350℃ and lower than 800℃
•
No upstream O2 sensor heater error | |
Threshold Value |
•
HO2S(S2) sensor voltage greater than 1.08 V | |
Diagnostic Time |
•
5 sec. | |
Mil On Condition |
•
3 driving cycles |
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor
