Perhaps even more so than the check engine light, the tire pressure monitoring system (TPMS) light is the most common warning light on a modern vehicle.
The TPMS light indicates that your car or truck’s tire pressure is above or below the minimum threshold set by the manufacturer.
TPMS has been legally required in the United States since the 2008 model year and is very reliable. When it does have problems, it’s usually a tire pressure sensor issue.
The most common reasons the TPMS light won’t go out are over or under-inflated tires or a tire pressure sensor-related issue.
How Tire Pressure Monitoring Systems Work
There are two main types of tire pressure monitoring technology.
Direct
Direct tire pressure monitoring systems come on virtually all new vehicles. They use sensors in each wheel to monitor tire pressure directly.
The sensors are wireless and transmit data to a receiver; if the data from any of these sensors indicate that your vehicle’s tire pressure is too low (usually 25% under the recommended pressure), the TPMS light will come on.
Indirect (a very uncommon setup)
Indirect tire pressure monitoring takes data from the wheel speed sensors. It uses this data to report if the tire pressure is low. If a tire gets too low, it’ll turn minutely faster than a full tire. The wheel speed sensors pick up on this and report it to the PCM.
What Should You Do if the TPMS Light is On?
Check and fill all the tires. Once you know the tire pressure checks out, the TPMS light stops becoming a safety concern, even if it doesn’t turn off.
99% of the time, if the TPMS light is on, getting the tire pressure back to the recommended pressure will turn it off.
You should check all the tires simultaneously to avoid going through this process again in a few weeks (tires without leaks lose pressure at about the same rate).
Check the Tire Pressure
Check the tire pressure on all four wheels with a tire pressure gauge. Verify that they match the manufacturer’s recommended psi. Overinflated tires can be just as dangerous as underinflated tires.
Add Air
Use the sticker on the inside of your vehicle’s door. It has the manufacturer’s recommended tire PSI and size.
If the tires are underinflated, add air. If the tires are overinflated, let some air out. Most gas stations have an air compressor that you can use to add air. Some service stations will let you program the air pressure, while others only have an air hose.
If you need help filling a tire, there’s a section on inflating tires at the end of this article.
What if adding air didn’t help?
If the TPMS warning light stays on after you’ve verified that the tire pressure is correct, jump down to the next section.
TPMS Light Staying On Causes
1. You Haven’t Driven Since Airing Your Tires
Most tire pressure monitoring systems want the vehicle to move a bit before they report that the tire pressure is better.
If you are reading this and haven’t moved your vehicle around, try driving it and see if the tire TPMS light turns off.
2. Incorrect Tire Pressure
The tire pressure is below the required level: If one or more of your tires has a pressure lower than recommended, your TPMS light will come on and stay lit until the pressure returns to the appropriate level.
If you’ve recently added pressure to your vehicle’s tires, it could be that you put TOO MUCH air in, which will keep the TPMS light on.
3. Faulty TPMS Sensor
The TPMS is likely reporting that the tire pressure is still too low. A faulty TPMS sensor can cause your light to come on. The defective sensor may need to be replaced or reset.
You may get a “service tire pressure monitoring system” warning or flashing TPMS light.
4. Low Battery in the TPMS Sensor
If the battery of your TPMS sensor is low, it can cause the light to come on. You may need to replace the battery for the light to turn off.
5. Damaged TPMS Valve Stem
The valve stem that transmits information from your tire to the TPMS system can become damaged or clogged, causing the light to come on. You may need to replace or clean this valve.
6. Issues After Rotating the Wheels
If you have recently rotated your wheels, the TPMS system may need reset.
Common Questions
Can you drive with the TPMS light on?
If your tire pressure light is on even after manually checking your vehicle’s tire pressure, it is entirely safe to drive with the TPMS light on. Just keep an eye on the tire pressure from time to time.
Driving with low tire pressure is not advisable. When your vehicle’s tire pressure is too low, it can cause damage to the sidewall, which can damage the integrity of the tire even after you inflate it.
Overinflation causes a tire to lose its ability to take impact from a bump. It also decreases the contact surface with the road and will show this by wearing more in the center (where it’s making contact with the road).
How do you check tire pressure?
Your vehicle may give you tire pressure data. But, even if it does, it’s better to verify all four wheels with a tire pressure gauge manually.
- Unscrew the valve stem cap.
- Push the tire pressure gauge down onto the valve stem.
- Observe the tire pressure/
What should your vehicle’s tire pressure be?
A sticker inside your vehicle’s driver door jamb should tell you the exact pressure for the front and rear wheels.
How long do TPMS sensors last?
The life expectancy of a TPMS sensor typically ranges from 5-10 years, depending on the type of sensor and the environment it is exposed to.
If one of the tire pressure sensors becomes damaged or its battery runs out of power before its expected lifespan, it can cause the TPMS light to come on in your vehicle’s dashboard.
Why is my TPMS light blinking?
The tire pressure light blinks to warn you that there is an issue with the tire pressure sensor (either defective or has a low battery) or the receiver is malfunctioning.
Conclusion
Most of the time, the TPMS will go off if you add air to the tires. If it doesn’t go off, it’s likely that there is an issue with one of the wheel pressure sensors.