DTC P0127: IAT Sensor: 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.

NOTE: ECM uses only the intake air temperature sensor (bank 1) for engine control and self-diagnosis. It does not use the intake air temperature sensor (bank 2).

Fig 1: Identifying Mass Air Flow Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.

< Reference data >

VOLTAGE CHART

Intake air temperature °C (°F)

Voltage⁽¹⁾ V

Resistance kΩ

25 (77)

3.3

1.800 - 2.200

80 (176)

1.2

0.283 - 0.359

⁽¹⁾	These data are reference values and are measured between ECM terminal 67 (Intake air temperature sensor) and ground.

CAUTION: Do not 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.

Fig 2: Resistance And Temperature Graph

Courtesy of NISSAN MOTOR CO., U.S.A.