1. Check the IAT Sensor: Locate the IAT sensor, which is usually positioned in the intake manifold or air intake hose. Inspect it for any visible damage or corrosion. If it appears damaged, it may need to be replaced.
2. Test the IAT Sensor: Disconnect the IAT sensor connector and use a multimeter to test its resistance. Compare the readings with the manufacturer's specifications to determine if the sensor is within range.
3. Inspect the Wiring: Check the wiring harness that connects the IAT sensor to the engine control unit (ECU) for any signs of damage, loose connections, or corrosion. Repair or replace any damaged wiring as needed.
4. Check ECU Communication: Use a diagnostic scan tool to check if the ECU is receiving a signal from the IAT sensor. If the ECU is not receiving a signal or the sensor reading is incorrect, the ECU may be faulty or the communication circuit may have a problem.
5. Clean the Intake: If the IAT sensor appears clean and functional, the issue might lie in the intake system. Clean the air intake and the throttle body to ensure unrestricted airflow.
6. Check for Vacuum Leaks: Inspect the intake manifold and vacuum hoses for any leaks. A vacuum leak can cause the air-fuel mixture to be incorrect, which can lead to IAT sensor errors.
7. Consult a Professional: If the issue persists after performing these checks and the IAT sensor readings remain incorrect or the check engine light stays on, it's advisable to consult with a qualified Audi technician or mechanic who can perform further diagnostic tests and address the problem more accurately.
Remember that trouble codes can be complex, and the exact steps for troubleshooting may vary depending on the specific model and year of your Audi. Refer to the vehicle's repair manual or technical documentation for more specific instructions and recommendations related to your vehicle.
