2019 Infiniti M35 V6-3.5L (VQ35HR) Diagnostic and Repair Information Page 252
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P0306, first perform the trouble diagnosis for DTC P0300,
P0301, P0302, P0303, P0304, P0305, P0306. See: P Code Charts/P0300.
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 CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
- For best results, perform at ambient temperature of ?10锟紺 (14锟紽) or higher.
- For best results, perform at engine coolant temperature of ?10锟紺 (14锟紽) to 56锟紺 (133锟紽).
- Before performing the following procedure, do not add fuel.
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select "COOLAN TEMP/S" in "DATA MONITOR" mode with CONSULT-III.
5. Check the indication of "COOLAN TEMP/S".
If it is below 56锟紺 (133锟紽), go to the next step.
If it is above 56锟紺 (133锟紽), cool engine down to less than 56锟紺 (133锟紽). Then go to next step.
6. Start engine and drive vehicle for 10 consecutive minutes under the following conditions.
7. Check 1st trip DTC.
With GST
Follow the procedure "With CONSULT-III" above.
Is 1st trip DTC detected?
YES - Go to See: P Code Charts/P0128.
NO - INSPECTION END
Diagnosis Procedure
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
See: P Code Charts/P0128.
Is the inspection result normal?
YES - INSPECTION END
NO - Replace engine coolant temperature sensor.
Component Inspection
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
