Checking the fuel trime value under detecting condition, if its average exceeds the limit over certain period, PCM/ECM sets P0172. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
| Item | Detecting Condition | Possible Cause | 
| DTC Strategy | 
										•
									 Monitor the fuel trim value | 1. Blocking of intake system 2. Fuel leakage in injector 3. Improper fuel pressure | 
| Enable Conditions | 
										•
									 Lambda control active 
										•
									 Engine coolant temperature > 163F | |
| Threshold Value | 
										•
									 Short term trim value at MIN Limit for more thin 40sec of total monitoring time 
										•
									 Short term trim > -30% | |
| Diagnostic Time | 
										•
									 90 sec | |
| Mil On Condition | 
										•
									 2 Drive Cycles |