What Does the TPMS Indicator Mean?

The gauge cluster on the dashboard of a vehicle is the normal location for the warning lights that indicate whether the tyre pressure is too low or too high. Warning lights are often yellow or amber in color and shaped like a tyre cross-section with an exclamation mark and/or the initials “TPMS” on them. When there is a significant drop in air pressure, this indicator light will turn on. If the warning light for low tyre pressure turns on, you shouldn’t ignore it since you could be about to get a flat tyre.

A leak might be the cause of low pressure, but it could also simply be a result of a tyre’s natural propensity to lose around one pound of pressure each month. Even if your tyres are adequately filled throughout the summer months, by the time winter rolls around, they may have lost enough pressure to trigger the tyre-pressure alert.

Likewise, if a light comes on when it’s still chilly in the morning, it could turn off later in the day if the surrounding temperature is warm enough to put the pressure on the tyres back to where they should be. The fact that tyres warm up while you drive, which raises their pressure by around 3 psi, is another reason why the wireless tyre pressure monitor alert can be on first thing each morning but turn itself off eventually in the day.

In either case, if a warning light for low tyre pressure appears on your dashboard, it is time to check the pressure in your tyres using a tyre-pressure gauge, which can be purchased for as little as $5. Checking the pressure in all of your tyres once a month can help you maintain them somewhere at optimal inflation level and therefore will allow you to pinpoint slow leakages early on possibly before the pressure falls enough for a warning light to turn on. 

If your tyre pressure monitoring system (TPMS) alert light does turn on, locate the nearest gas station or garage and assess the pressure of all the tyres (as well as the spare, if possible). Add air to any tyres that have a pressure that is lower than the range that is listed on a sticker located within the driver’s door.

After you have driven several miles with the tyres having the correct amount of air in them, the warning light should turn off. If the indicator does not turn off automatically after about 10 kilometres, the Tyre Pressure Monitoring System (TPMS) might need to be recalibrated by the instructions provided in the owner’s handbook for the vehicle.

If the warning light turns on but none of your tyres’ pressures is outside of the permissible range, it’s possible that the sensor that monitors your tyre pressure is faulty and has to be replaced. If the tyre-pressure warning light comes on, pay attention to it; not only will this make you safer, but it will also help you prevent damage to your tyres if the problem turns out to be something else.

the authorBerryMcewen