PCM/ECM sets DTC P0138 if the HO2S(B1S2) voltage remains excessively high for a predetermined time.
| Item | Detecting Condition | Possible Cause | 
| DTC Strategy | 
										•
									 Voltage range check(short circuit to battery) | 1. Short to Battery in signal harness 2. Poor connection or damaged harness 3. Faulty Heated O2 Sensor (HO2S) | 
| Enable Conditions | 
										•
									 10V< Battery voltage <16V | |
| Threshold Value | 
										•
									 1.2V< HO2S(B1S2) | |
| Diagnostic Time | 
										•
									 1sec. | |
| Mil On Condition | 
										•
									 2 Drive Cycles |