P0128

DTC P0128 THERMOSTAT FUNCTION




On Board Diagnosis Logic

DTC Confirmation Procedure

NOTE: If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

TESTING CONDITION:
- For best results, perform at ambient temperature of -10 °C (14 °F) or higher.
- For best results, perform at engine coolant temperature of -10 °C (14 °F) to 71 °C (160 °F).

WITH CONSULT-II
1. Replace thermostat with new one. Use only a genuine NISSAN thermostat as a replacement. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch ON.




3. Select "COOLAN TEMP/S" in "DATA MONITOR" mode with CONSULT-II.
4. Check that the "COOLAN TEMP/S" is above 71 °C (160 °F).
If it is below 71 °C (160 °F), go to following step.
If it is above 71 °C (160 °F), cool down the engine to less than 71 °C (160 °F), then retry from step 1.

5. Drive vehicle for 10 consecutive minutes under the following conditions.

VHCL SPEED SE: 80 - 120 km/h (50 - 75 MPH)

If 1st trip DTC is detected, go to "Diagnostic Procedure" below.

WITH GST
Follow the procedure "WITH CONSULT-II".

Step 1:

Diagnostic Procedure

Component Inspection

ENGINE COOLANT TEMPERATURE SENSOR







1. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.
2. If NG, replace engine coolant temperature sensor.