Tire pressure light: what it means and what to do
The tire pressure light tells you that one or more tires has low pressure. A light that flashes and then stays on tells you that the system has a fault.
What the light tells you
FMVSS No. 138 applies to cars, SUVs, pickups and vans with a gross vehicle weight rating of 10,000 lb or less. It does not apply to vehicles with dual wheels on an axle.1
The light comes on when at least one tire is significantly underinflated.2 The standard sets the latest point. The light must come on within 20 minutes when a tire falls to a set pressure. This pressure is 25 percent below the placard pressure, or the minimum for that type of tire. The higher of the two applies.3
| Tire type | Minimum pressure in Table 1 | Source |
|---|---|---|
| Passenger (P-metric), standard load | 20 psi (140 kPa) | 4 |
| Passenger (P-metric), extra load | 23 psi (160 kPa) | 4 |
| Load range C | 29 psi (200 kPa) | 4 |
| Load range D | 35 psi (240 kPa) | 4 |
| Load range E | 35 psi (240 kPa) | 4 |
Steady light or flashing light
- A steady light shows that at least one tire is significantly underinflated.2
- A light that flashes for 60 to 90 seconds and then stays on shows a fault in the system.5
- When the system has a fault, it can fail to detect or show low tire pressure.6
What to do when the light comes on
- Check the tire pressure as soon as possible.2
- Look at each tire for damage.2
- Find the cold pressure on the vehicle placard on the driver's side B-pillar.7
- Add air until each tire has the placard pressure. The light goes off when the tires have the correct pressure.2
- If the light flashes and then stays on, ask your vehicle dealer for a system inspection.2
The light is not a pressure check
“Please note that the TPMS is not a substitute for proper tire maintenance”
The light comes on only when a tire is about a quarter below the correct pressure.8 Check the pressure of each tire, and also the spare, one time each month when the tires are cold.69