Be Ready for your Car’s Seasonal Tire Pressure Check

Tire Pressure Monitor SymbolRare Tire Pressure Light w/ArrowsWe are just past mid-August, the days are getting shorter and a little autumn crispness can be felt in the air in the early morning. At least, north of the Equator! This brings to mind your car’s equivalent of Seasonal Affective Disorder, your Tire Pressure Monitoring System or TPMS.

TPMS Malfunction IndicatorIf equipped, one of the two TPMS warning indicators shown above (or a text version – TPMS) will soon do its best to get your attention.  (Drivers most commonly describe the images in the two lights above as horseshoes with exclamation points or arrows in them but they are actually a “slice” of a tire.)


Why does TPMS become active with the season? Because air shrinks when it cools. Thus 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.

In truth, 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.

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 be happy to have you available for additional service!

Three other points are worth making. First, having this warning light come on can in fact be annoying to drivers as well, but it only rarely indicates a system problem. The light is doing its job and alerting you to the risk of low tire pressure.

Second, do not ignore the possibility that one tire may have picked up a nail or other object and is actually leaking air, which will also activate the 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!

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 another on filling the 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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