P0128

DTC P0128 COOLANT THERMOSTAT (COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE)

1. OUTLINE OF DIAGNOSIS
Detect malfunctions of the thermostat.
Judge as NG when the engine coolant temperature is lower than the estimated engine coolant temperature and the difference between them is large. Judge as OK when the engine coolant temperature becomes to 75 degrees C (167 degrees F), and the difference is small, before judging NG.




2. COMPONENT DESCRIPTION




3. ENABLE CONDITIONS

4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.

5. DIAGNOSTIC METHOD




Abnormality Judgment
Judge as NG when the continuous time until completing the malfunction criteria becomes 23 second or more.




Normality Judgment
Judge as OK and clear the NG when the malfunction criteria are met.

6. DTC CLEAR CONDITION
- When the OK idling cycle is completed 40 times in a row
- When "Clear Memory" is performed

7. MALFUNCTION INDICATOR LIGHT CLEAR CONDITIONS
- When the OK driving cycle is completed 3 times in a row
- When "Clear Memory" is performed

8. FAIL SAFE
None

9. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)