DTC Detection Logic
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble diagnosis for 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 being stuck open.
| DTC No. | CONSULT screen terms (Trouble diagnosis content) |
DTC detecting condition | Possible cause |
|---|---|---|---|
| P0128 | THERMSTAT FNCTN [Coolant thermostat (coolant temperature below thermostat regulating temperature)] |
The engine coolant temperature does not reach to specified temperature even though the engine has run long enough. |
|