DTC Detection Logic
NOTE:
If DTC P0128 is displayed with DTC PP0300, P0301, P0302, P0303 or P0304, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to
"DTC LOGIC ".
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough.
This is due to a leak in the seal or the thermostat stuck being open.
DTC DETECTING CONDITION CHART
| DTC No. | Trouble diagnosis name | DTC detecting condition | Possible cause |
|---|---|---|---|
| P0128 | Thermostat function | The engine coolant temperature does not reach to specified temperature even though the engine has run long enough. |
|