Nissan Murano: Dtc/circuit Diagnosis / P0128 Thermostat Function

DTC Description

DTC DETECTION 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.

The engine coolant temperature does not reach to specified temperature even though the engine has run long enough.

POSSIBLE CAUSE

• Thermostat

• Leakage from sealing portion of thermostat

• Engine coolant temperature sensor

FAIL-SAFE

Not applicable

NOTE:

Never refuel before and during the following procedure.

CHECK DTC PRIORITY

If DTC P00128 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 and P0306.

Is applicable DTC detected?

Perform diagnosis of applicable.

• DTC P0300: Refer to DTC Description.

• DTC P0301: Refer to DTC Description.

• DTC P0302: Refer to DTC Description.

• DTC P0303: Refer to DTC Description.

• DTC P0304: Refer to DTC Description.

• DTC P0305: Refer to DTC Description.

• DTC P0306: Refer to DTC Description.

GO TO 2.

PRECONDITIONING-I

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.

GO TO 3.

PRECONDITIONING-II

With CONSULT

1. Turn ignition switch ON.

2. Check the following conditions:

   Ambient temperature	−10°C (14°F) or more
   A/C switch	OFF
   Blower fan switch	OFF

3. Select “DATA MONITOR” mode of “ENGINE” using CONSULT.

4. Check the following conditions:

   COOLANT TEMP/S

   −10°C – 46°C (14 – 114°F)

Is the condition satisfied?

GO TO 4.

1. Satisfy the condition.

2. GO TO 4.

PERFORM DTC CONFIRMATION PROCEDURE-I

With CONSULT

1. Start engine.

2. Drive the Nissan Murano vehicle until the following condition is satisfied.

   CAUTION:

   Always drive vehicle at safe speed.

   1. STEP 1

      Drive the Nissan Murano vehicle under the conditions instructed below until the difference between “COOLANT TEMP/S” and “FUEL T/TMP SE” becomes at least 24°C (75°F).

      COOLANT TEMP/S	65°C (149°F) or less
      FUEL T/TMP SE	Less than the value calculated by subtracting 25°C (45°F) from “COOLANT TEMP/S”.*

      *: Example

      COOLANT TEMP/S	FUEL T/TMP SE
      70°C (158°F)	45°C (113°F) or less
      65°C (149°F)	40°C (104°F) or less
      60°C (140°F)	35°C (95°F) or less

   2. STEP 2

      Drive the Nissan Murano vehicle at 50 km/h (32 MPH) or more with the difference between “COOLANT TEMP/S” and “FUEL T/TMP SE” maintained at 24°C (75°F) or more.

      NOTE:

      Keep the accelerator pedal as steady as possible during cruising.

   3. STEP 3

      Drive the Nissan Murano vehicle at 50 km/h (32 MPH) or more until “COOLANT TEMP/S” increases by 6°C (43°F).

      NOTE:

      Keep the accelerator pedal as steady as possible during cruising.

Is the condition satisfied?

GO TO 5.

GO TO 1.

PERFORM DTC CONFIRMATION PROCEDURE-II

With CONSULT

1. Drive the Nissan Murano vehicle until the following condition is satisfied.

   COOLANT TEMP/S

   65°C (149°F) or more

   CAUTION:

   Always drive Nissan Murano vehicle at safe speed.

2. Check 1st trip DTC.

Is 1st trip DTC detected?

Proceed to Diagnosis Procedure.

To check malfunction symptom before repair: Refer to Intermittent Incident.

Confirmation after repair: INSPECTION END

CHECK DTC PRIORITY

If DTC P00128 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 and P0306.

Is applicable DTC detected?

Perform diagnosis of applicable.

• DTC P0300: Refer to DTC Description.

• DTC P0301: Refer to DTC Description.

• DTC P0302: Refer to DTC Description.

• DTC P0303: Refer to DTC Description.

• DTC P0304: Refer to DTC Description.

• DTC P0305: Refer to DTC Description.

• DTC P0306: Refer to DTC Description.

GO TO 2.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Check engine coolant temperature sensor. Refer to Component Inspection.

Is the inspection result normal?

GO TO 3.

Replace engine coolant temperature sensor.

CHECK THERMOSTAT

Check thermostat. Refer to Removal and Installation.

Is the inspection result normal?

INSPECTION END

Replace thermostat. Refer to Removal and Installation.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

1. Turn ignition switch OFF.

2. Disconnect engine coolant temperature sensor harness connector.

3. Remove engine coolant temperature sensor. Refer to Exploded View.

4. Check resistance between engine coolant temperature sensor terminals as per the following.

   

Is the inspection result normal?

INSPECTION END

Replace engine coolant temperature sensor. Refer to Exploded View.