DTC P0128 Coolant Thermostat (Engine Coolant Temperature Below Thermostat Regulating Temperature)
WARNING: This page is about a different car, the 2006 Subaru Outback. However, it is still accessible from the selected car via links, so may be relevant.
DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault
- GENERAL DESCRIPTION < Ref. to DTC P0128 COOLANT THERMOSTAT (ENGINE COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE) , Diagnostic Trouble Code (DTC) Detecting Criteria. >
TROUBLE SYMPTOM:
Thermostat remains open.
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode < Ref. to
OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to
PROCEDURE , Inspection Mode. >.
DTC P0128 COOLANT THERMOSTAT (ENGINE COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE) - DIAGNOSTIC PROCEDURE
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK VEHICLE CONDITION. | Was the vehicle driven or idled with the engine partially submerged under water? | In this case, it is not necessary to inspect DTC P0128? | Go to step 2. |
| 2 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 3. |
| 3 CHECK ENGINE COOLANT. | Are coolant level and mixture ratio of cooling water to antifreeze solution correct? | Go to step 4. | Replace the engine coolant. < Ref. to REPLACEMENT , Engine Coolant. > |
4 CHECK RADIATOR FAN.
|
Does the radiator fan continuously rotate for more than 3 minutes during idling? | Repair radiator fan circuit. < Ref. to RADIATOR MAIN FAN AND FAN MOTOR . > and < Ref. to RADIATOR SUB FAN AND FAN MOTOR . > | Replace the thermostat. < Ref. to THERMOSTAT . > |