Some models of the Audi A4 are equipped with a tire pressure monitoring system that uses sensors to track the air pressure in each tire. If the computer detects a drop in tire pressure in one or more of the tires, a warning message lights up on the instrument cluster. After you correct the low pressure, you need to reset the system so it can accurately track the pressure in each tire. The system may also need to be reset if you rotate or replace the tires.
Park the A4 on a level surface.
Fill each tire to the appropriate air pressure. The recommended pressure is printed on the sidewall of each tire. Use a tire pressure gauge to make sure the pressure is correct.
Drive the A4 at above 25 miles per hour for approximately 10 to 15 minutes. Once the computer has received enough information from the sensors, the warning light will reset.