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 deviation of long term fuel trim control in Idle | 1. Air restriction in intake or exhaust system 2. Front HO2S or MAFS contamination 3. Faulty sensor signals 4. EVAP system 5. Fuel system |
Enable Conditions |
•
No relevant failure
•
Lambda adaptation active | |
Threshold Value |
•
Idle long term fuel trim has reached Max. Limit for more than 20 sec. within 90 sec ＜ -0.005 g/rev( -2.5mg/stk) | |
Diagnostic Time |
•
90 sec. | |
MIL On Condition |
•
2 Drive Cycles |
