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 P2188 if no proportional post catalyst fuel trim adaptation occurs for a defined time after the lambda controller has reached its minimum threshold at idle.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Monitoring the deviation of short term fuel trim | 1. Poor Connector Connection 2. Air restriction in Intake or Exhaust System 3. Dirty Engine Oil or Oil Level Too High 4. Defected Upstream O2 Sensor 5. Defected MAP Sensor 6. Defected Fuel System 7. Defected EVAP System 8. Faulty Sensor Signals |
Enable Conditions |
•
Engine Coolant Temp. higher than 163.4℉(73℃)
•
Idle Lambda adaptation active conditions : ▶ Engine speed lower than 900 RPM ▶ Mass Fuel Flow(MFF) lower than 0.032 g/rev | |
Threshold Value |
•
Idle long term fuel trim equal to -0.007 g/rev | |
Diagnostic Time |
•
90 sec. | |
MIL On Condition |
•
2 Driving Cycle |
