Nissan Sentra Service Manual: P0127 IATSensor
DTC Logic
DTC DETECTION LOGIC
| DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
| P0127 | IAT SENSOR-B1 (Intake air temperature too high) | Rationally incorrect voltage from the sensor is sent to ECM, compared with the voltage signal from engine coolant temperature sensor. |
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
- Turn ignition switch OFF and wait at least 10 seconds.
- Turn ignition switch ON.
- 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
- 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).
- Turn ignition switch ON.
- Select “DATA MONITOR” mode of “ENGINE” using CONSULT
- Start engine
- Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
CAUTION:
Always drive vehicle at a safe speed.
- 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
- Turn ignition switch OFF.
- Disconnect mass air flow sensor harness connector and reconnect it again.
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT.
- 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".
P0125 ECT Sensor
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P0125 is displayed with P0116, first perform the trouble
diagnosis for DTC P0116. Refer to EC-
196, "DTC Logic".
If DTC P0125 is displ ...
P0128 Thermostat function
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304,
first perform the trouble
diagnosis for P0300, P0301, P0302, P0303 or P0304. Refer to ...
Other materials:
The steering switch (meter control switch) is inoperative
Description
If any of the following malfunctions is found for the steering switch (meter
control switch) operation.
All switches are inoperative
The specified switch cannot be operated
Diagnosis procedure
1.Check steering switch signal circuit
Check the steering switch signal circuit. ...
Ecm branch line circuit
Diagnosis Procedure
1.CHECK CONNECTOR
Turn the ignition switch OFF.
Disconnect the battery cable from the negative terminal.
Check the terminals and connectors of the ECM for damage, bend and loose
connection (unit side and
connector side).
Is the inspection result normal?
YES > ...
P0171 Fuel injection system function
DTC Logic
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture
ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the
A/F sensors 1. The ECM calculates
the necessary compensation to correct th ...