Nissan Sentra Service Manual: P0127 IATSensor

DTC Logic

DTC DETECTION LOGIC

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:

This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test is expected to be easier, it is unnecessary to lift the vehicle.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT

1. Wait until engine coolant temperature is less than 96В°C (205В°F)

• Turn ignition switch ON.
• Select “DATA MONITOR” mode of “ENGINE” using CONSULT.
• Check the engine coolant temperature.
• If the engine coolant temperature is not less than 96В°C (205В°F), turn ignition switch OFF and cool down engine.

NOTE:

Perform the following steps before engine coolant temperature is above 96В°C (205В°F).

2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode of “ENGINE” using CONSULT
4. Start engine
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.

CAUTION:

Always drive vehicle at a safe speed.

6. Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT” above.

Is 1st trip DTC detected? YES >> Proceed to EC-205, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.CHECK INTAKE AIR TEMPERATURE SENSOR

Check the intake air temperature sensor. Refer to EC-206, "Component Inspection".

Is the inspection result normal? YES >> Check intermittent incident. Refer to GI-39, "Intermittent Incident".

NO >> Replace mass air flow sensor (with intake air temperature sensor). Refer to EM-25, "Exploded View".

Component Inspection

1.CHECK INTAKE AIR TEMPERATURE SENSOR

1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor harness connector and reconnect it again.
3. Turn ignition switch ON.
4. Select “DATA MONITOR” mode with CONSULT.
5. Check that the indicated value of “INT/A TEMP SEN” is almost the same as intake air temperature.

Is the inspection result normal? YES >> INSPECTION END

NO >> Replace mass air flow sensor (with intake air temperature sensor). Refer to EM-25, "Exploded View".

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