DTC Diagnosis Procedure
1.
CHECK DTC PRIORITY
If DTC P0128 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
Is applicable DTC detected?
Perform diagnosis of applicable. Refer to
DTC Index
.
.
2.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Check the engine coolant temperature sensor. Refer to
Component Inspection
.
Is the inspection result normal?
.
Replace engine coolant temperature sensor. Refer to
Exploded View
.
3.
CHECK THERMOSTAT
Check the thermostat. Refer to
Removal and Installation
.
Is the inspection result normal?
INSPECTION END
Replace thermostat.