Step 1: Use the Change Oil light?
The Low Tire Pressure light next to the Change Oil light also does not really know if one tire is low. It makes a secondary measurement that is usually explained by low tire pressure. It compares the number of revolutions each tire makes. If a tire is low, it has a smaller effective diameter and must turn more times per minute to keep up with the fully inflated tire on the opposite side of the car. My Low Tire Pressure light has remained "on" since a mechanic worked on the braking system a couple of years ago.