On Board Diagnosis Logic
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to
[P0300, P0301, P0302, P0303, P0304 MISFIRE
].
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 being stuck open.
DTC DETECTING CONDITION CHART
| DTC No. | Trouble diagnosis name | DTC detecting condition | Possible cause |
|---|---|---|---|
| P0128 0128 |
Thermostat function | The engine coolant temperature does not reach to specified temperature even though the engine has run long enough. |
|