P0127

P0127 IAT Sensor

Component Description
The intake air temperature sensor is built into mass air flow sensor (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]






CAUTION: Never use ECM ground terminals when measuring input/output voltage.Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

P0127:

DTC Confirmation Procedure

CAUTION: Always drive vehicle at a safe speed.

NOTE: If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

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.

WITH SDT
1. Wait until engine coolant temperature is less than 90 °C (194 °F)
a. Turn ignition switch ON.
b. Select Data list mode with SDT.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90 °C (194 °F), turn ignition switch OFF and cool down engine.
- Perform the following steps before engine coolant temperature is above 90 °C (194 °F).

2. Start engine.
3. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to [P0127 IAT Sensor].

WITH GST
Follow the procedure With SDT above.

Diagnosis Procedure

Step 1-3:

Component Inspection

INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor (1) terminals 5 and 6 under the following conditions.






2. If NG, replace mass air flow sensor (with intake air temperature sensor).