DTC Detection Logic
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P0306, first perform the trouble diagnosis for 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 being stuck open.
| DTC No. | Trouble diagnosis (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. |
|