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 the deviation of short term fuel trim | 1. Poor Connector Connection 2. Air leakage or restriction in Intake or Exhaust System 3. Defected Upstream O2 Sensor 4. Defected MAP Sensor 5. Defected Fuel System 6. Defected EVAP System 7. Faulty Sensor Signals |
Enable Conditions |
•
Engine Coolant Temp. higher than 163.4℉(73℃)
•
Part Load Lambda adaptation active conditions : ▶ Engine speed higher than 900 RPM and lower than 4000 RPM ▶ Mass Fuel Flow(MFF) higher than 0.014 g/rev and lower than 0.066 g/rev | |
Threshold Value |
•
Part Load long term fuel trim equal to 25% | |
Diagnostic Time |
•
90 sec. | |
MIL On Condition |
•
2 Driving Cycle |
