Tire Pressure Light: What to Do
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The horseshoe-shaped tire pressure light means at least one tire is about 25% below its recommended pressure — or, if it flashes at startup, that the monitoring system itself has a fault. Most of the time the fix is five minutes at an air pump. Here's exactly what to do, in order.
If a tire is visibly flat, the steering pulls, or you hear flapping, don't drive to the pump — fit the spare or call for help; driving on a flat destroys the tire and can damage the wheel. Check pressures when tires are cold (parked 3+ hours) for an accurate reading.
What you'll need
- Tire pressure gauge (a few dollars — keep one in the glovebox)
- Access to an air pump (gas station or portable inflator)
- Driver's door-jamb sticker (your car's pressure spec)
- Owner's manual (for the reset procedure)
The steps
Tap through one step at a time — built for one-handed use at the roadside — or switch to all 7 steps to read ahead or print.
Step 1 of 7: Read the light: steady vs flashing
Step 1: Read the light: steady vs flashing
A light that flashes for about a minute at startup, then stays on, means a TPMS fault (usually a dead sensor battery) — the car can't tell you the pressures. A light that simply comes on and stays on means low pressure in at least one tire. That's the case this guide covers.
Step 2: Find YOUR car's correct pressure
Open the driver's door and find the tire information sticker on the door jamb (or check the fuel flap or owner's manual). It lists the recommended cold PSI for front and rear tires. The number molded into the tire sidewall is the tire's maximum, not the target — don't inflate to it.
Step 3: Check all four tires with a gauge
Unscrew the valve cap, press the gauge squarely onto the valve stem until the hiss stops, and read the pressure. Do all four (and the spare, if full-size) — more than one tire is often low, and the light doesn't tell you which.
Step 4: Inflate to the sticker pressure
Add air in short bursts, re-checking with the gauge, until each tire matches the door-jamb figure for its position. If you overfill, press the valve stem's center pin briefly to let air out. Expect to add 1 PSI for every 10°F the weather has dropped since you last checked.
Step 5: Drive a few minutes — most lights reset themselves
Most systems re-measure once you're rolling and turn the light off within a few minutes of driving above ~20 mph. Give it 10 minutes of normal driving before assuming anything else is wrong.
Step 6: Still on? Use the manual reset
Some cars need a manual reset: a dedicated TPMS button (often under the dash or in the glovebox) held until the light blinks, or a 'calibrate' option in the vehicle settings menu. The procedure varies widely — follow your owner's manual exactly.
Step 7: Light keeps coming back? Find the leak or the bad sensor
A tire that loses pressure again within days has a slow puncture or a leaking valve — have it inspected and repaired. If all pressures hold but the light stays on (or flashes at startup), a sensor battery has died; sensors run $50–$150 each installed and typically last 5–10 years.
Related warning lights
If you see one of these, check what it means and whether you can keep driving before starting any work.
Frequently asked questions
Sources
Where the figures on this page come from. Your owner's manual still wins for your specific vehicle.
- 49 CFR § 571.138 — Standard No. 138; Tire pressure monitoring systemsU.S. Code of Federal Regulations, via Cornell Law School LII. Cited for: S4.2 requires the low tire pressure telltale to light at 25% below the vehicle manufacturer's recommended cold inflation pressure, or the tire-type minimum in Table 1, whichever is higher. Checked .
- Keeping Your Vehicle in ShapeU.S. Department of Energy and U.S. EPA (fueleconomy.gov). Cited for: the proper pressure for a vehicle is the one on the driver's-side door-jamb sticker, the glove box, or the owner's manual — not a figure read off the tire. Checked .