DTC P0125: EXCESSIVE TIME TO ENTER CLOSED LOOP Kia Optima I

Uses same test as P0116. See DTC P0116: ENGINE COOLANT TEMPERATURE (ECT) SENSOR RANGE/PERFORMANCE MALFUNCTION, OR DTC P0125: INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL .

Diagnostic Aids

DTC P0128 will set when engine coolant temperature at engine start takes longer than a predetermined amount of time.

Check for following possible problems

1. ECT sensor malfunction.
2. Poor connections between ECT sensor and Engine Control Module (ECM).
3. Thermostat stuck open.