If the sensor output is below 0.06 V and the average of voltage difference between loaded and unloaded voltage is below 0.015 V under enable conditions, the ECM sets DTC P0137.
Item | Detecting Condition | Possible Cause | |
Case 1 | DTC Strategy |
•
Signal check, low by Load pulse | 1. Poor connection 2. Short to ground in signal circuit 3. S2 |
Enable Conditions |
•
Duration of down O2S < 0.06V for more than 3 sec.
•
Load pulse : End of 3rd pulse | ||
Threshold Value |
•
Average of voltage difference between loaded and unloaded voltage < 0.015 V | ||
Diagnostic Time |
•
3 sec. | ||
Case 2 | DTC Strategy |
•
Signal check, low | |
Enable Conditions |
•
Short term FT < 1.25 (upper limit)
•
B+ > 10.7 V
•
Heat quantity from exhaust gas
•
Around downstream O2S > 1~312 kJ | ||
Threshold Value |
•
Downstream O2S voltage < 0.06 V | ||
Diagnostic Time |
•
40 sec. | ||
MIL ON Condition |
•
2 driving cycles | ||
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor
