Most modern cars have a tire pressure monitoring system (TPMS) that most people don't even know about. A TPMS is a system that is intended to recognize early signs of underinflated or deflated tire pressure. It has many sensors on each tire that can send out a warning light to your dashboard whenever it reads a dangerous pressure. The TPMS light looks like a horseshoe or tire with an exclamation symbol in the middle of it. Whenever you see this light on your dash, it means you require maintenance and to do a manual pressure reading.   The TPMS light essentially means that there's something wrong with your tires, that something is causing them to be underinflated. The best thing you can do when you see this light is pull over to a safe spot. Using a pressure gauge, you should manually check each tire. Most gas stations have a tire pressure station where you can measure and fill your tires.   Tire pressure is measured in two units: psi (pound-force per square inch) and kPa (Kilopascal). In the US, we use psi. To find how many psi your tires require, you should examine the sticker on the driver's door frame. If you can't find it, you can always refer to your owner's manual. You should never exceed the recommended psi because overinflation of tires can be just as bad as underinflated tires. Overinflating your tires will lead to insufficient tire traction and premature wear; your tires will be prone to wear only on the center. On the other hand, underinflated tires will cause wear on the outer portions of the tire.    Other TPMS Behavior If the TPMS illuminates on your dash and suddenly turns off while driving, it shouldn't be a cause for concern. If it turns off subsequently, it's usually related to changes in tire temperature.  If the TPMS light flashes repeatedly, it is a sign that the light itself is malfunctioning. It would be best if you got this light fixed soon. If you require TPMS repairs, please do not hesitate to come by Rainier Automotive!