The ambient air temperature (AAT) sensor is a thermistor that measures the temperature of the outside air. The AAT sensor is located in the front bumper of the vehicle.
The AAT sensor is used by the engine control module (ECM) to calculate the intake air temperature. The intake air temperature is used by the ECM to adjust the fuel mixture and ignition timing.
If the AAT sensor fails, the ECM will default to a fixed intake air temperature value. This can cause the engine to run rich or lean, and may also cause the engine to stall.
Symptoms of a bad AAT sensor
The following are some of the symptoms of a bad AAT sensor:
* Engine running rich or lean
* Engine stalling
* Poor fuel economy
* Check engine light on
How to test the AAT sensor
You can test the AAT sensor using a multimeter. To do this, follow these steps:
1. Disconnect the electrical connector from the AAT sensor.
2. Set the multimeter to the ohms setting.
3. Connect the positive lead of the multimeter to one terminal of the AAT sensor and the negative lead to the other terminal.
4. The multimeter should display the resistance of the AAT sensor. The resistance should be between 100 and 10,000 ohms.
5. If the resistance of the AAT sensor is not within the specified range, the sensor is bad and should be replaced.
How to replace the AAT sensor
To replace the AAT sensor, follow these steps:
1. Locate the AAT sensor in the front bumper of the vehicle.
2. Disconnect the electrical connector from the AAT sensor.
3. Remove the AAT sensor from the vehicle.
4. Install the new AAT sensor in the vehicle.
5. Connect the electrical connector to the AAT sensor.
