If the lambda controller reaches the maximum or minimum threshold, then feedback control is no longer possible and emissions will be increased. The PCM/ECM sets DTC P2191 if no proportional post catalyst fuel trim adaptation occurs for a defined time after the lambda controller has reached its maximum threshold at part load.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Monitoring deviation of long term fuel trim control in part load | 1. Air leakage in intake,exhaust or EVAP system 2. Faulty PCV system 3. Faulty sensor signals 4. Fuel system |
Enable Conditions |
•
No relevant failure
•
Lambda adaptation active
•
Coolant Temp. > 73℃(163℉) | |
Threshold Value |
•
Part load long term fuel trim > +25% | |
Diagnostic Time |
•
90 sec. | |
MIL On Condition |
•
2 Driving Cycles |
