DTC Detection Logic
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P306, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306. 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 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. |
|