P0127

P0127 IAT SENSOR

Description






The intake air temperature sensor is built-into mass air flow sensor (bank 1) (1). The sensor detects intake air temperature and transmits a signal to the ECM.
The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise.





[Reference data]







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

1.Wait until engine coolant temperature is less than 90�C (194�F)
-Turn ignition switch ON.
-Select "DATA MONITOR" mode with CONSULT.
-Check the engine coolant temperature.
-If the engine coolant temperature is not less than 90�C (194�F), turn ignition switch OFF and cool down engine.
NOTE:
Perform the following steps before engine coolant temperature is above 90�C (194�F).
2.Turn ignition switch ON.
3.Select "DATA MONITOR" mode with 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.
Is 1st trip DTC detected?
YES- Go to "Diagnosis Procedure" .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK GROUND CONNECTION

1.Turn ignition switch OFF.
2.Check ground connection M95. Refer to Ground Inspection in "Circuit Inspection" Circuit Inspection.
Is the inspection result normal?
YES- GO TO 2.
NO- Repair or replace ground connection.

2. CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to "Component Inspection" .
Is the inspection result normal?
YES- GO TO 3.
NO- Replace mass air flow sensor (with intake air temperature sensor) (bank 1). Refer to "Exploded View" Exploded View.

3. CHECK INTERMITTENT INCIDENT

Refer to "Intermittent Incident" Intermittent Incident.
- INSPECTION END


Component Inspection


1. CHECK INTAKE AIR TEMPERATURE SENSOR

1.Turn ignition switch OFF.
2.Disconnect mass air flow sensor (bank 1) harness connector.
3.Check resistance between mass air flow sensor (bank 1) terminals as follows.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace mass air flow sensor (with intake air temperature sensor) (bank 1). Refer to "Exploded View" Exploded View.