If the signal output satisfies the threshold value under enable conditions, ECM sets DTC P0134.
( 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 | 1. Poor connection 2. Open or short in signal circuit 3. S1 | 
| Enable Conditions | 
										•
									 Dew point end detected 
										•
									 Fuel feed back control active 
										•
									 Battery voltage > 11V 
										•
									 Exhaust Gas temperature = 280℃~800℃ 
										•
									 No injector error 
										•
									 No upstream O2 sensor heater error | |
| Threshold Value | 
										•
									 Sensor voltage : 0.4~0.6V | |
| Diagnostic Time | 
										•
									 5 sec | |
| MIL ON Condition | 
										•
									 3 driving cycle | 
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor