The intake air temperature sensor (IAT Sensor), built-in type in the MAP sensor, is a resistor-based sensor which detects the intake air temperature. According to the intake air temperature information from the sensor, the ECM will control the necessary amount of fuel injection.
The MIL is ON or the DTC is displayed on the HI-SCAN under the following condition;
When the intake air temperature is detected below -40°C or higher than 120°C.
Check item | Data display | Check conditions | Engine state | Test specification |
Intake air temperature sensor | Air temperature | Ignition switch : ON or engine running | When 0°C (32°F) | 4.0 ~ 4.4V |
When 20°C (68°F) | 3.3 ~ 3.7V | |||
When 40°C (104°F) | 2.5 ~ 2.9V | |||
When 80°C (176°F) | 1.0 ~ 1.4V |
Using a multimeter, measure the IAT sensor resistance between terminals 3 and 4.
IG. SW. ON | Temperature °C | Resistance (kΩ) |
0 (32) | 4.5 ~ 7.5 | |
20 (68) | 2.0 ~ 3.0 | |
40 (104) | 0.7 ~ 1.6 | |
80 (176) | 0.2 ~ 0.4 |
If the resistance deviates from the standard value, replace the intake air temperature sensor assembly.
