DTC P0128: Coolant Thermostat (Engine Coolant Temperature Below Thermostat Regulating Temperature): Notes
WARNING: This page is about a different variant/trim than selected.
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
- Thermostat remains open.
- Coolant temperature rises slowly.
CAUTION:
After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to
OPERATION
, Clear Memory Mode and Inspection Mode Ref. to
PROCEDURE
, Inspection Mode.
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK FOR ANY OTHER DTC ON DISPLAY. | Is any other DTC displayed? | Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . | Go to step 2 |
| 2 CHECK ENGINE COOLANT. | Is the check result OK? | Go to step 3 | Refill the engine coolant. Ref. to ENGINE COOLANT |
3 CHECK RADIATOR FAN.
|
Does the radiator fan continuously rotate for 3 minutes or more during idling? | Repair radiator fan circuit. Ref. to RADIATOR FAN AND FAN MOTOR ASSEMBLY | Go to step 4 |
| 4 CHECK ENGINE COOLANT TEMPERATURE SENSOR. Check the engine coolant temperature sensor. Ref. to INSPECTION , Engine Coolant Temperature Sensor. |
Is the check result OK? | Replace the thermostat. Ref. to THERMOSTAT . | Replace the engine coolant temperature sensor. Ref. to ENGINE COOLANT TEMPERATURE SENSOR |