Intake Air Temperature Sensor — checking and replacing (Mazda Capella GF)

Examination

1. The air temperature sensor is a thermistor that changes its resistance depending on the temperature. When the resistance of the thermistor changes, the value of the voltage removed from it also changes. As the temperature decreases, the sensor's resistance increases, and as the temperature increases, it decreases. A faulty air temperature sensor is detected by the diagnostic system, and a corresponding code is stored in its memory.

4-cylinder engines and various U-6 engines produced since 1998

2. The sensor is screwed into the air cleaner (see figure 1.1, a). Measure the resistance of the sensor. To do this, disconnect its electrical connector.

3. Measure the resistance at the sensor contacts. It should be in the range of 35.5-39.2 kOhm at room temperature (20°C). Start the engine or remove the sensor and heat it with a hair dryer. The sensor resistance should drop to 7-8 kOhm at 60°C. If the test yields different results, replace the sensor. If the engine was running with the connector disconnected, be sure to clear the fault code that occurred in this case.

V-shaped engines produced from 1993 to 1997

4. Disconnect the air flow sensor electrical connector. Connect an ohmmeter to the IAT and GND terminals (see Figure 5.3,b). The resistance should be between 2-3 kOhm at room temperature (20°C). Start the engine or remove the sensor and heat it with a hair dryer. The sensor's resistance should drop to 400-700 ohms at 60°C. If the test yields different results, replace the sensor. If the engine was running with the connector disconnected, be sure to clear the fault code that occurred in this case.

Replacement

5. Disconnect the negative cable from the battery.

Caution: If your vehicle's audio system is equipped with a theft-deterrent feature, make sure you have the unlock code before disconnecting the battery.

(Text taken from an online platform: «Mazbook»)