If ECM/PCM detects short to ground in signal circuit, ECM/PCM sets DTC P0137.
( This DTC might be caused by the malfunction of Heater circuit, so, check the heater circuit first. )
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case 1 |
•
Signal check, low by Load pulse | 1. Poor connection 2. Short to ground in signal circuit 3. Downstream O2S |
Case 2 |
•
Signal check, low | ||
Enable Conditions | Case 1 |
•
[Duration of down O2S < 0.06V] > 3 sec.
•
Load pulse : End of 3rd pulse | |
Case 2 |
•
Short term FT < 1.25 (upper limit)
•
Battery voltage > 10.7V
•
Heat quantity from exhaust gas around downstream O2S > 1~312kJ | ||
Threshold Value | Case 1 |
•
Average of voltage difference between loaded and unloaded voltage < 0.015V | |
Case 2 |
•
Downstream O2S voltage < 0.06V | ||
Diagnosis Time |
•
- | ||
MIL On Condition |
•
2 trips | ||
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor
