If the lambda controller reaches the maximum or minimum threshold, then feedback control is no longer possible and emissions will be increased. The PCM 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 Drive Cycles |
