Key takeaways
A solid TPMS light means at least one tire is significantly underinflated, typically 25 percent or more below the carmaker's recommended cold pressure. A light that flashes for 60 to 90 seconds at startup and then stays on means the monitoring system itself has a fault. Either way, check every tire with a gauge and fill it to the pressure on the driver's door placard.
- 01Cold snaps are a common trigger. Michelin says tires lose about 1 PSI for every 10°F drop, so a light that shows up on a frosty morning still means you need air.
- 02Federal rules have required TPMS on new cars, SUVs, pickups and vans since the 2008 model year, yet AAA testing found some systems don't warn until a tire is more than 25 percent low.
- 03Many cars clear the light on their own after you inflate the tires. Others need a reset button, a menu calibration or a sensor relearn after a rotation or new tires.
- 04Sensor batteries are sealed inside the sensor and usually last 5 to 10 years, so a dead battery means a new sensor.
This guide belongs to our OBD2 guide: dashboard warning lights section, which covers the wider topic.
The TPMS light is the amber symbol that looks like a horseshoe with an exclamation point inside. A solid light means at least one tire is significantly underinflated. A light that flashes for 60 to 90 seconds at startup and then stays on means the system has a malfunction, as NHTSA's tire safety guidance explains.
The fix is often simple: a gauge, an air pump and the pressure on your door placard. This guide covers what triggers the light, what federal rules require, how to reset it on Toyota, Honda, Ford, GM, Hyundai and Kia models, and what sensors cost.
The tire pressure warning is one of the amber lights in our dashboard warning lights explained guide, which explains what each symbol's color means and how soon to act. Amber means you can keep driving carefully, but deal with this one the same day.
TPMS Light Meanings at a Glance
How the light behaves tells you which problem you have.
| What you see | What it usually means | What to do |
|---|---|---|
| Solid light | A tire is about 25% or more below recommended cold pressure | Check every tire with a gauge and add air today |
| Flashes 60 to 90 seconds at startup, then stays on | System fault, such as a dead sensor battery | Have it checked, and check pressures by hand meanwhile |
| On during a cold morning, off after driving | Pressure is hovering near the warning point | Add air to the placard pressure anyway |
| Comes back soon after you add air | Possible puncture or slow leak | Have the tire inspected |
| On after a rotation, new tires or the spare | Sensors need a relearn, or a wheel has no sensor | Follow the reset steps in your manual |
Based on NHTSA, FMVSS No. 138, Bridgestone, Continental Tire and the Honda, Hyundai and Kia owner's manuals.
What Is TPMS and When Does the Light Turn On?
A tire pressure monitoring system watches your tire pressures and turns on a warning when one falls well below the carmaker's recommended cold pressure. NHTSA says every passenger car, light truck and van from the 2008 model year on must have one.
The requirement comes from the TREAD Act, which Congress passed on November 1, 2000. NHTSA's 2012 TPMS effectiveness study says the final rule followed in 2005 and applied to every vehicle built on or after September 1, 2007. NHTSA notes that some 2006 and 2007 models have TPMS too.
The rule itself is federal safety standard FMVSS No. 138. It covers vehicles with a gross vehicle weight rating of 10,000 pounds or less, except those with dual wheels on an axle. The warning must come on within 20 minutes of driving once a tire is 25 percent below the recommended cold pressure, or at a set minimum, whichever is higher.
The 25 percent rule in real numbers
Continental Tire's TPMS guide says a tire that calls for 35 PSI triggers the light at around 26 PSI or lower, and that tires can be 5 to 20 percent low without setting it off. The standard also sets a floor by tire type, and the warning must come on by that pressure at the latest.
| Tire type | Minimum activation pressure |
|---|---|
| P-metric, standard load | 20 PSI |
| P-metric, extra load | 23 PSI |
| Load Range C | 29 PSI |
| Load Range D and E | 35 PSI |
From Table 1 of FMVSS No. 138 (49 CFR 571.138).
Why the warning can come late
The 25 percent mark is a legal limit, not a precise trigger. In AAA's 2023 TPMS research on 11 vehicles from the 2022 to 2024 model years, five lit the warning at 75 percent of posted pressure and five of the others waited until 70.3 to 72.9 percent. One gave no warning even at 65 percent.
The displayed readings were accurate, within 3.3 percent at worst. Bridgestone adds that a system may miss a low tire if the other tires are losing pressure at the same rate. AAA's advice is to check pressure monthly with a gauge, even when the light is off.
The bulb check at startup
FMVSS No. 138 requires the light to come on as a lamp check when you switch the ignition on. If it never lights during that check, the warning may not be working. That's why our used car inspection checklist has buyers watch every warning light come on and then go out once the engine runs.
Solid vs Flashing TPMS Light: What Each One Means
A solid light means low tire pressure. A light that flashes for about a minute at each startup and then stays on means the system has found a fault.
Under FMVSS No. 138, a light that handles both warnings must flash for 60 to 90 seconds, then stay on for as long as the fault exists, repeating at every startup. The Hyundai, Kia and 2023 Toyota GR Corolla manuals all describe the flash as lasting about one minute.
The Chevrolet warning light guide says a light that stays on means a tire is significantly underinflated, while one that keeps flashing at startup means the system might need service.
Don't shrug off a flashing light just because your tires seem fine. Bridgestone's TPMS light guide warns that a malfunctioning system can't warn you about low pressure until it's repaired.
When the tires are fine but the light stays on
If every tire checks out at the placard pressure, the fault is usually in the system itself.
- A dead sensor battery, which is sealed inside the sensor.
- A sensor damaged during tire mounting, a risk Bridgestone lists for direct systems.
- A sensor that needs a relearn, or a wrong or misprogrammed replacement sensor, both faults Schrader links to the blinking warning.
- A spare or replacement wheel with no working sensor.
- Signal interference. Kia's 2024 owner's manual names power supply cables, radio transmitters such as those at airports and broadcasting stations, snow chains, laptops, mobile chargers and remote starters.
Direct vs Indirect TPMS
Direct systems put a pressure sensor inside each wheel, which on Hyundai models sits behind the valve stem. Indirect systems have no pressure sensors and use the ABS wheel-speed sensors to spot a tire that rolls differently because it has lost air.
| Feature | Direct TPMS | Indirect TPMS |
|---|---|---|
| How it detects low pressure | Sensor in each wheel | Wheel-speed sensors compare how each tire rolls |
| Shows which tire is low | On some vehicles | Usually not |
| Battery to wear out | Yes, sealed in each sensor | None |
| After inflating or rotating | May need a relearn, sometimes with a tool | Must be recalibrated |
| Weak spots | Sensors can be damaged during tire service | Less accurate, and a tire size change can throw it off |
From Bridgestone, NHTSA, Continental Tire, Discount Tire and the Honda and Hyundai owner's manuals.
Bridgestone's explainer on how TPMS works says indirect systems cost less and need less upkeep but must be reset after you inflate or rotate the tires. Direct systems give real readings from inside the tire and can cover the spare, but they cost more.
The 2023 Honda CR-V uses an indirect system. Honda's 2023 CR-V TPMS manual pages say it compares the rolling radius of each wheel, doesn't monitor tires at low speed and isn't triggered by overinflation.
Why Is My TPMS Light On?
A solid light points to air pressure: a cold snap, a puncture or months of slow seepage. If every tire is at the right pressure and the light won't clear, look at the system faults listed above, recent tire work or the spare.
Cold weather and overnight temperature drops
Michelin's winter driving tips say tires lose about 1 PSI for every 10°F drop in temperature. Continental's example is a cold snap from 70°F to 30°F cutting pressure by 4 PSI.
That's why the light often appears after a cold night. NHTSA notes it may come on for a short time on cold mornings and then turn off, and Bridgestone says it may clear as the car warms up. AAA still says not to ignore the warning if it goes off after driving.
Our Tire Pressure Calculator estimates what your tires should read after a temperature change and how much air gets you back to the placard number.
Free tool
Tire Pressure Calculator. Enter your placard pressure, the pressure and temperature when you last set the tires, and today's temperature to see the expected reading and how much air to add.
Slow leaks, punctures and natural air loss
AAA Club Alliance's TPMS explainer says tires lose about 1 PSI per month on their own, and Continental puts natural seepage at 1 to 2 PSI per month. Skip a few months of checks and the losses add up.
Continental says a nail, screw or other sharp object in the tread can cause a slow leak, and AAA Club Alliance also lists hitting a pothole or curb. If you suspect a puncture, it advises pulling over to inspect the tire.
What to Do When the TPMS Light Comes On
Check every tire with a gauge as soon as you can safely stop, fill any low tire to the door placard pressure, then drive and see whether the light goes out.
- Note whether it's solid or flashing. Flashing at startup means a system fault, so check the pressures by hand.
- Look at all four tires. Continental says not to keep driving on a visibly flat tire.
- Drive gently to air. Hyundai's 2026 owner's manual says to slow down, avoid hard cornering and allow longer stopping distances.
- Check pressure cold if you can. NHTSA counts tires as cold after at least three hours parked, and says to allow for the extra pressure in warm tires.
- Use the door placard number, not the maximum pressure printed on the sidewall.
- Fill every low tire, and the spare if it's monitored.
- Drive and give the system time. NHTSA says the symbol goes out once the tires are properly inflated, though some cars need a reset first.
- Get help if the light stays on. Bridgestone advises a professional inspection at that point.
Door placard vs sidewall: finding the right PSI
NHTSA says the correct pressure is the one the vehicle maker lists, found on the Tire and Loading Information label on the driver's door edge or doorjamb, or in the owner's manual. Bridgestone points out that the sidewall number is the tire's maximum pressure, not the one to fill to. If front and rear figures differ, set each axle to its own.
Some Chevrolets help you fill. Chevrolet's Tire Fill Alert, which Chevrolet says is available on most 2018 and newer vehicles, flashes the nearest turn signal while you add air and chirps the horn once at the recommended pressure.
How to Reset the TPMS Light by Carmaker
On many cars the light goes out by itself a few minutes after the tires are inflated. Others need a reset button, a menu calibration or a sensor relearn. Either way, set every tire to the placard pressure first, as Honda's manual instructs before calibration.
| Brand | Example from the maker | How the reset works | When it's needed |
|---|---|---|---|
| Toyota | 2015 RAV4, 2023 GR Corolla | Hold SET, or use the TPWS menu, until the light blinks three times | After adjusting pressure, rotating or replacing tires |
| Honda | 2023 CR-V | TPMS calibration in vehicle settings, then about 30 minutes of driving at 31 to 62 mph | After adjusting pressure, rotating or replacing tires |
| Ford | Ford Performance sensor kit | Ignition and brake sequence, then a tool wakes each sensor | New sensors, and rotations where front and rear pressures differ |
| GM | GM relearn procedure | Learn mode by key fob or driver information center, then a tool wakes each sensor | New sensors and rotations |
| Hyundai and Kia | Hyundai and Kia owner's manuals | Automatic within a few minutes of driving | See a dealer if the light stays on |
From Toyota's quick reference guides, the 2023 Honda CR-V manual, Ford Performance kit instructions, Brake & Front End's GM relearn guide and Hyundai and Kia owner's manuals. Your own manual is the final word.
Toyota
The 2015 Toyota RAV4 quick reference guide says to turn the engine switch to ON, hold the SET button until the indicator blinks three times, then wait a few minutes for initialization to finish.
Some newer models use the display instead. The 2023 GR Corolla quick reference guide goes through Vehicle Settings, then TPWS, then Tire Pressure Setting, after which the light slowly blinks three times.
Honda
On the CR-V's 7-inch touchscreen, press Home, then choose Settings, Vehicle settings, TPMS calibration and Calibrate. Calibration finishes on its own during driving. Remove snow chains first, and note that it can't be calibrated with the compact spare on.
Ford
The Ford Performance TPMS kit instructions start training mode with a set sequence of ignition cycles and brake presses, until the horn sounds once and the TPMS light flashes. A tool held at each valve stem then wakes the sensors, left front, right front, right rear and left rear, with no more than 2 minutes between tires.
GM vehicles
Brake & Front End's GM relearn guide enters learn mode by holding the fob's LOCK and UNLOCK buttons, or through the driver information center, with the ignition on. The horn sounds twice, then a TPMS tool wakes each sensor in the same order, with a chirp for each. Waiting more than two minutes cancels the process.
A dedicated tool isn't the only option. Some scan tools in our roundup of the best OBD2 scanners list TPMS among their service resets.
Hyundai and Kia
Hyundai's 2026 manual says the light goes off within a few minutes of driving once the sensor-equipped wheel is inflated and refitted. Kia's manual section on tire replacement with TPMS says the same and adds that a spare's sensor must be activated by a professional workshop.
Check before you use tire sealant
Kia's manual says never to use tire sealant on a vehicle with TPMS, because liquid sealant can damage the pressure sensors, and not to use any puncture repair agent Kia hasn't approved.
Tire Rotation, New Tires and Spare Tire Sensors
After a rotation or new tires, the system may need a reset or relearn. Check the TPMS light before you leave the shop. The federal standard has owner's manuals tell drivers to check the malfunction light after replacing any tire or wheel.
Toyota and Honda call for a reset after a rotation or new tires. Ford's instructions require retraining after a rotation when front and rear pressures differ, and the GM guide says shops should reset sensor positions after a rotation. Discount Tire adds that indirect systems need calibrating after tire service or air adjustments, and Continental says some vehicles relearn sensor positions on their own within 10 to 50 miles of driving.
Schrader's guide to serviceable TPMS parts says to replace the valve service kit, the serviceable valve parts that on most sensors include the stem, every time a tire comes off the wheel, because skipping it can lead to slow leaks.
Spare tires and TPMS
FMVSS No. 138 doesn't require the spare to be monitored. Ford's TPMS support page says its system leaves the spare out, and Hyundai's manual says its spare has no sensor, so the light stays on while it's fitted.
Some vehicles do monitor the spare. Continental suggests checking it if the light comes on with no obvious cause, and NHTSA says to check every tire, spare included, at least monthly.
Is It Safe to Drive With the TPMS Light On?
It's usually fine to drive a short distance at low speed to reach air, as long as no tire is visibly flat. Driving for days on a low tire isn't, because an underinflated tire can overheat and fail.
The federal standard requires every owner's manual to carry that overheating warning, and NHTSA counted 511 deaths in tire-related crashes in 2024. Continental says a brief drive under 5 miles at low speed is reasonable, and that tires should be checked and inflated within 24 hours. Ford says to stop and check your tires as soon as possible.
With a flashing light, the car may drive normally, but nothing will warn you if a tire goes low. Keep checking pressures by hand until it's fixed.
Stop driving if you notice any of these
Pull over safely if a tire looks flat, you hear thumping or flapping, the steering turns very heavy, other warning lights come on, or you smell burning rubber. Continental lists each one as a reason to stop immediately.
TPMS Sensor Battery Life and Replacement Cost
Sensor batteries are sealed inside the sensor, and most sources put their life at 5 to 10 years. When one dies, the whole sensor is replaced, which Continental prices at $50 to $150 per sensor, installed.
Schrader's TPMS sales guide gives an average battery life of five to 10 years, Continental also says 5 to 10 years and Bridgestone says about a decade. Discount Tire says 6 to 10 years or 90,000 to 120,000 miles. Schrader's driver leaflet is the outlier at 3 to 5 years.
| Service | Typical cost | Source |
|---|---|---|
| TPMS diagnosis and reset at a shop | $50 to $150 | Continental Tire |
| One sensor replaced, installed | $50 to $150 | Continental Tire |
| All four sensors replaced | $200 to $600 | Continental Tire |
| Valve stem and service kit, per wheel | $10 to $20 | Continental Tire |
| Average TPMS sensor replacement | $314 to $368 | Kelley Blue Book |
| TPMS check, air and light reset | Free | Discount Tire and America's Tire |
From Continental Tire's TPMS guide, Kelley Blue Book's TPMS sensor cost page and Discount Tire's TPMS facts page.
The price sources disagree. Kelley Blue Book's TPMS cost guide puts the average at $314 to $368 without breaking out parts and labor, well above Continental's per-sensor shop figure. Ask for a quote that lists the sensor, programming and service kit separately.
A free check can rule out simple causes first. Discount Tire's TPMS facts page says its stores and America's Tire stores offer free TPMS checks, inflation and light resets.
When to See a Mechanic or Tire Shop
Go to a tire shop or dealer when the light flashes at startup, stays on with every tire at the right pressure, or keeps coming back.
- The light flashes for about a minute at each startup, then stays on.
- Every tire is at placard pressure and the light won't clear. Honda's manual says to have a dealer inspect the car then.
- One tire keeps losing air.
- The light came on after new tires or a rotation, and a reset hasn't cleared it.
- A sensor needs replacing. Continental says that isn't a practical DIY job, since the tire must be dismounted and rebalanced and the sensor programmed.
A Gauge Still Beats the Warning Light
TPMS cuts down on badly underinflated tires, but it doesn't replace a monthly gauge check.
NHTSA's 2012 study of 6,103 vehicles found TPMS cut the likelihood of a severely underinflated tire, 25 percent or more below recommended, by 55.6 percent. Even so, 11.8 percent of 2004 to 2007 vehicles with direct TPMS still had one, against 23.1 percent without it. NHTSA also says only 19 percent of consumers properly inflate their tires.
For rotation intervals, tread depth and tire age limits, see the tires and wheels section of our car maintenance guide.
Treat a solid TPMS light as a same-day job for the air pump and a flashing one as a repair to book soon. A monthly check, with the tires cold and the door placard as your target, keeps you ahead of the warning.
Frequently Asked Questions
Does the TPMS light come on when tires are overinflated?
Sometimes. Federal rules only require a warning for low pressure, but Bridgestone says the light can come on when a tire is significantly over- or underinflated. Not every system works that way, and Honda's 2023 CR-V manual says overinflation does not trigger its indirect system. Bridgestone adds that overinflated tires tend to wear in the center and lose grip, so let air out until you reach the placard pressure.
What's the difference between the TPMS light and the tire pressure light?
On many cars they are the same light: the amber horseshoe symbol with an exclamation point, which means low pressure when solid and a system fault when it flashes for about a minute at startup. Federal rules also let carmakers use a separate malfunction light marked with the letters TPMS. Some Kia manuals also describe position telltales that point to the low tire.
Do I need to replace all four TPMS sensors at once?
You can replace only the failed sensor, but replacing all four together often makes sense. Schrader notes that sensors are usually installed at the same time, so when one battery dies the others tend to follow soon after, and doing them all during a scheduled service saves time and money. Continental puts four sensors at $200 to $600 installed, against $50 to $150 for one.
Can you permanently turn off the TPMS light?
Not through a dealer or repair shop. Federal law, 49 U.S.C. 30122, bars manufacturers, dealers, rental companies and repair businesses from knowingly making inoperative any safety device installed to meet a federal safety standard, and TPMS is required by FMVSS No. 138. The light goes out once the low tire is inflated or the fault is repaired, though some cars need a reset first.
How much does low tire pressure hurt gas mileage?
The federal FuelEconomy.gov site says underinflated tires can lower gas mileage by about 0.2 percent for every 1 PSI drop in the average pressure of all tires. It adds that keeping tires at the proper pressure improves mileage by 0.6 percent on average, and by up to 3 percent in some cases. The site says to use the door-jamb or glove-box sticker, not the sidewall maximum.
Sources and References
- NHTSA. Tire Safety Ratings and Awareness (TireWise)
- NHTSA. Evaluation of the Effectiveness of TPMS in Proper Tire Pressure Maintenance (DOT HS 811 681)
- eCFR (National Archives). 49 CFR 571.138: Standard No. 138, Tire Pressure Monitoring Systems
- Cornell Law School Legal Information Institute. 49 U.S. Code 30122: Making Safety Devices and Elements Inoperative
- FuelEconomy.gov (U.S. Department of Energy and EPA). Keeping Your Vehicle in Shape
- AAA Newsroom. Don't Let Your Tire Pressure Monitoring System Leave You Feeling Flat
- AAA Club Alliance. What Is a TPMS Light, and Why Is It On?
- Continental Tire. TPMS Warning Light: What It Means and What to Do
- Bridgestone Tires. TPMS Light On? What It Means and What You Need to Do
- Bridgestone Tires. What Is TPMS and How Does It Work?
- Michelin. Winter Tire Timing and PSI Tips
- Schrader TPMS Solutions. Selling TPMS at the Counter: Not What But Why
- Schrader TPMS Solutions. Serviceable vs. Replaceable TPMS Components
- Schrader TPMS Solutions. Everything You Need to Know About TPMS (driver education leaflet)
- Discount Tire. What Is TPMS
- Kelley Blue Book. Tire Pressure Monitoring System (TPMS) Sensor Replacement Cost
- Honda. 2023 CR-V Owner's Manual: Tire Pressure Monitoring System (TPMS)
- Toyota. 2015 RAV4 Quick Reference Guide
- Toyota. 2023 GR Corolla Quick Reference Guide
- Ford Performance. M-1180-A TPMS Sensors and Activation Tool Kit Installation Instructions
- Ford. What Is the Tire Pressure Monitoring System?
- Brake & Front End. GM TPMS: The Setup and Relearn Procedures
- Chevrolet. How to Use Tire Fill Alert
- Chevrolet. Identify Warning Lights
- Hyundai. 2026 Hyundai Owner's Manual: Tire Pressure Monitoring System (TPMS)
- Kia. Kia Owner's Manual: Tire Replacement With TPMS
- Kia. 2024 Kia Owner's Manual: TPMS Malfunction Indicator
Written by
CarTipsMentor Team
Researched from the sources listed above and checked against them before publishing. Nobody paid to be mentioned on this page. It is general information, not advice about your own vehicle.
Published . Last updated .
