Checking output signals from HO2S under detecting condition, if the HO2S's response time is too long, ECM/PCM sets P0139.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case 1 |
•
Transient time monitor (Rich to Lean) | 1. Poor connection 2. Downstream O2S 3. ECM/PCM |
Case 2 |
•
Transient time monitor (Lean To Rich) | ||
Enable Conditions | Case 1 |
•
Battery voltage > 11.0V
•
1200rpm < Engine speed < 3520rpm
•
Exhaust Gas temperature around downstream O2S > 425 ℃
•
Intergrated Exhaust gas mass flow > 0.2 kg/h
•
Exhaust gas mass flow > 10 kg/h
•
-150kg/h < Delta Exhaust gas mass flow < 150kg/h
•
Fuel system status : Fuel cut off
•
Downstream O2S voltage before fuel cut > 0.63V | |
Case 2 |
•
Battery voltage > 11.0V
•
1200rpm < Engine speed < 3520rpm
•
Exhaust Gas temperature around downstream O2S > 425 ℃
•
Intergrated Exhaust gas mass flow > 0.2 kg/h
•
Exhaust gas mass flow > 8 kg/h
•
-30kg/h < Delta Exhaust gas mass flow < 50kg/h
•
Fuel system status : After a fuel cut off
•
Downstream O2S voltage before fuel cut < 0.25V | ||
Threshold Value | Case 1 |
•
Transient time(average) > 0.30 sec. | |
Case 2 |
•
Transient time(average) > 0.45 sec. | ||
Diagnosis Time |
•
- | ||
MIL On Condition |
•
2 trips | ||
