Temperature-related pressure loss and a slow leak do not look exactly the same

All four tires are down by a similar amount
Checking the effect of a broad temperature drop

Set pressure when the tires are cold to the vehicle placard value, then watch whether the readings remain stable.

One tire is repeatedly lower than the others
Inspecting for a puncture, bead leak, or valve issue

Repeatedly adding air can hide the pattern without fixing the leak.

The warning flashes before staying on
Checking the owner's manual for a TPMS system fault

A flashing sequence can indicate a sensor or system problem rather than simply low pressure.

Use a repeatable cold-pressure check

  1. 01
    Read the vehicle placard

    Use the recommended cold pressures on the driver's door jamb or owner's manual, which may differ front to rear.

  2. 02
    Measure before significant driving

    Check when the tires have been parked long enough to be near ambient temperature rather than immediately after highway driving.

  3. 03
    Adjust all tires consistently

    Bring each tire to the specified cold pressure and include the spare if the vehicle uses a monitored or serviceable spare.

  4. 04
    Recheck after the next cold soak

    A tire that falls again while the others remain stable deserves a leak inspection.

Safety check

Do not bleed warm tires down to the cold-pressure number

Pressure normally rises as tires warm. Releasing air from a warm tire to match the cold placard can leave it underinflated after it cools. If a tire is visibly damaged or very low, avoid normal-speed driving until it is evaluated.

Useful notes for a tire shop

  • Cold PSI for all four tires
  • Outside temperature when the warning appeared
  • How often the same tire needs air
  • Any recent puncture repair or wheel work
  • Whether the TPMS indicator flashes before staying on