Bridgestone Team | 5 min read 

When the Tire Pressure Monitoring System (TPMS) warning light turns on, it means that at least one tire is significantly under- or over-inflated. The purpose of this system is to alert you to potential unsafe driving conditions. Modern TPMS uses sensors inside your tires to continually monitor their pressure and transmits this data to your car’s electronic control unit (ECU). When the system detects potentially hazardous pressure, it activates the tire pressure light warning on your dashboard.

If you see the TPMS light illuminated, it’s important to recognize what really matters—your safety and your tires’ health. In this guide, you’ll learn what it means and the clear steps to take when this crucial warning appears.

Overinflation and underinflation can both result in premature treadwear and increase the risk of tire failure. When they’re overinflated, tires lose their grip, wear out faster, and aren’t able to absorb bumps. 

Overinflated tires will typically wear in the center. 

Underinflated tires will respond sluggishly, lose fuel efficiency, produce more heat, and risk overload. You’ll notice underinflated wear mostly at the shoulders or sides.

If you’re learning about tire pressure sensors for the first time, finding the TPMS indicator on your dashboard is simple. It’s a horseshoe-shaped light with an exclamation point in the center. 

In many newer vehicles, the dashboard screen doesn’t just show the TPMS warning light—it also displays a message or graphic indicating which tire is low, along with the exact pressure readings for each wheel.

When you see the low tire pressure TPMS symbol light up, it means that at least one tire is significantly under- or over-inflated.

1. The first thing to do is manually check your tire pressures with a gauge.
2. Add air until the pressures reach the vehicle manufacturer specification. (You’ll find the correct pressure on the driver’s door jamb or in the owner’s manual, not on the sidewall of the tire- that’s the tire’s maximum pressure.)
3. Reset TPMS if required (see manual for steps)
4. If light stays on, have the system inspected by a professional.

Keep in mind, your TPMS does not replace routine tire pressure maintenance.  It’s an alert, but a tire may be below spec before the warning appears. The TPMS light comes on if the pressure is too low or too high.

If your tire pressures are close to the alert level, fluctuating temperatures can cause the TPMS light to go on and off. Typically, you’ll see the light if pressure drops overnight with the cold, and it’ll go off as the pressure rebounds later in the day as the car warms up. 

If the light flashes for approximately 60 to 90 seconds every time you start your car and then remains illuminated, this means the TPMS isn’t functioning properly and you should take it to an automotive service center for an inspection. Until repaired, the TPMS is out of order and is not able to warn you of low tire pressure. In both cases, check the air pressure of all of the tires with a gauge and add air to the tires that need it.

No! Understanding what a TPMS warning light means and what to do when it lights up is an important part of a driver’s responsibility. But it shouldn’t be a replacement for regular tire pressure checks. Why? Depending on the situation, the TPMS may have limitations such as:

• The TPMS warning light may be set to illuminate below the tire pressure needed to carry the load in the vehicle.
• The sensor(s) may not be accurately transmitting tire pressure data to the on-board computer.
• The system may not be able to accurately determine if a tire is too low if other tires are losing pressure at the same rate.

Therefore, even with TPMS, you should check tire pressure once a month, and before a long trip or when carrying extra load. Regularly inspecting and maintaining proper tire pressure is the simplest way to stay safe, save fuel, and extend the life of your tires.