Seven Things to Know About Tire Pressure Monitoring Systems

Its Fall and time once again for your car’s equivalent of Seasonal Affective Disorder, your Tire Pressure Monitoring System or TPMS. If equipped, one of the two TPMS warning indicators shown will soon attempt to get your attention (Drivers most commonly describe the lights as horseshoes with exclamation points or arrows in them but they are actually a “slice” of a tire). Here are seven things you should know about TPMS.

Tire Pressure Monitor Symbol1) Unlike any other yellow/amber or red light, these indicators do not normally point to a problem with the car. Rather they are meant to inform. It may be annoying, but the light is doing its job and alerting you to the risk of low tire pressure.


Rare Tire Pressure Light w/Arrows2) The light comes on (first) in the fall primarily because air shrinks when it cools. So as autumn takes hold and the weather cools, the air in your tires will shrink causing the pressure in your tires to go down. If you are fortunate enough to have a system that also shows the actual pressure in your tires, you will be able to see that they have all “lost” the same amount of pressure.

3) No air has actually been lost – it is simply that the existing air is no longer capable of filling the same space! In colder climates, you will likely be prompted to add air to your tires two or three times before the onset of spring. Note that tires will warm while driving, and so the light may resolve itself after a few miles. You will see the light again once the tires cool down. Also, if you garage your vehicle at night, you may only see the light while out and about in the cool air, which can be confusing.

TPMS Malfunction Indicator4) The text indicator, TPMS, is a Malfunction Indicator only. If your vehicle is equipped with this additional tell tale and it remains lit, the Tire Pressure Monitoring System is not operating and needs to be checked by a qualified repair facility.

5) If your vehicle has only the picture symbols AND there is a malfunction, the indicator will flash. Have it checked by a qualified repair facility.

6) Do not ignore the possibility that one tire may have picked up a nail or other object and is actually leaking air. This will activate the same warning light. Make a visual inspection of your tires any time the light comes on. A leaking tire will quite likely look “flatter” than the other three. Get to your favorite service department fast!

7) No other system in your car requires attention due to the season! Fortunately, the cure is relatively simple, and while service departments dislike the annoyance of constant calls regarding TPMS light “trouble” in the fall, most will check and refill your tires at no cost. After all, they will and should be happy to have you available for additional service!

And finally, if your car is NOT equipped with a Tire Pressure Monitoring System, your tires will still need some seasonal help. Check your tire pressures!

Related posts and videos:

Tire Pressure Monitoring System Indicators


TPMS video.

And this one, helping you fill your tires!


At, we developed two Mobile Apps to help drivers with the most common questions asked of service departments everywhere: “What is this light on my dashboard?” And “My car says ‘Key Not Detected’. How do I get into and start my push-button start car?” With these two apps, we have your six. Check them out here.

Mobile Apps


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