If the sensor output signal is over 1.08V under enable conditions, the ECM/PCM sets DTC P0138.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Voltage Range check | 1. Poor connection 2. Short to power in signal circuit 3. HO2S(S2) |
Enable Conditions |
•
10V < Battery voltage < 16V | |
Threshold Value |
•
Downstream O2 Sensor Voltage > 1.2V | |
Diagnostic Time |
•
Continuous | |
Mil On Condition |
•
2 driving cycles. |
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor