P0128

DTC P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

Wiring Diagram

Wiring Diagram:

DTC Detecting Condition and Trouble Area

DTC Detecting Condition And Trouble Area:

DTC Confirmation Procedure

WARNING:
^ When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during testing to avoid occurrence of an accident.
^ Road test should be carried out with 2 persons, a driver and a tester, on a level road.

NOTE: Check to make sure that the following conditions are satisfied when using this "DTC Confirmation Procedure".
^ Intake air temperature at engine start: -7 °C (19 °F) to 200 °C (392 °F)
^ Intake air temperature: -10 °C (14 °F) to 200 °C (392 °F)
^ Engine coolant temperature at engine start: between -10 °C (14 °F) and 56 °C (132 °F)
^ The following DTCs are not detected: DTCs related to MAF sensor and ECT sensor (other than P0128)

1. With ignition switch OFF, connect scan tool.
2. Turn ON ignition switch, clear DTC.
3. Drive vehicle more than 40 mph (65 km/h) for 20 min. or more.
4. Check DTC and pending DTC.

DTC Troubleshooting

Step 1-3:

Step 4-6: