Contents: Examination ⇊ Replacement ⇊
Examination
1. The IAT sensor is a thermistor (a resistor whose resistance depends on temperature). A change in resistance causes a change in the amplitude of the sensor signal voltage, and the HIGHER the temperature, the LOWER the resistance, and vice versa. Sensor failures result in the recording of the P0112 or P0113 fault code in the self-diagnostic system memory.
2. Check the resistance of the IAT sensor. Disconnect the electrical connector of the sensor located on the intake manifold.
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3. Using an ohmmeter, measure the resistance between the two terminals on the sensor. The resistance of the sensor depends on the temperature and at 20°C should be approximately 2500÷3500 Ohm. Start the engine (or remove the sensor and warm it up with a hair dryer). At 83°C, the resistance of the sensor should drop to 250÷350 Ohm. If the test results are negative, replace the IAT sensor.
Note: If the engine was running with the sensor disconnected, be sure to clear the self-diagnostic system memory (see Section On-Board Diagnostics (OBD) System - Operating Principle and Error Codes).
Replacement
1. Disconnect the negative cable from the battery.
Warning! If the car stereo system is equipped with a security code, make sure you have the correct combination to activate the audio system before disconnecting the battery!
2. Disconnect the wiring from the IAT sensor.
3. Remove the sensor from the intake air duct plenum housing.
4. Installation is carried out in reverse order.