DTC P0127: IAT Sensor: Description

WARNING: This page is about a different car, the 2011 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.

The intake air temperature sensor is built-into the 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 rise in temperature.

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.

TEMPERATURE RESISTANCE REFERENCE 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 terminals 67 (Intake air temperature sensor) and 68 (Sensor ground).

Fig 2: Intake Air Temperature Resistance Graph

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