Checking the fuel trime value under detecting condition, if its average exceeds the limit over certain period, PCM sets P0171. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
Monitoring deviation of short term fuel trim control | 1. Air leakage 2. Improper fuel pressure 3. PCV valve stuck 4. Clogging of injector |
Enable Conditions |
•
No Failure detection for DTCs | |
Threshold value |
•
Short term trim value at MAX Limit for more thin 40sec of total monitoring time
•
short term trim ＞ +50% | |
Diagnosis Time |
•
90 sec | |
MIL On Condition |
•
2 Driving Cycles |
