Reset the Tyre Pressure Monitor (TPMS)

Last updated: June 10, 2026

If the tyre-pressure warning has come on in your Subaru Legacy (2014–2019) — the BN B4 — after you’ve adjusted the pressures or changed a wheel, you reset it by setting the pressures and driving. Here’s how.

When to Reset

• After checking or adjusting the tyre pressures.
• After changing wheels or tyres, or fitting winter wheels.

Resetting the System

1. Park level and set all four tyres to the correct cold pressures (placard in the driver’s door shut).
2. Drive the vehicle for about 10 minutes at over 40 km/h (25 mph).
3. The system relearns the corrected pressures and the warning clears.

If the Warning Stays On

• Recheck every tyre — one below spec keeps the warning on.
• Complete the learn drive — short trips may not be enough.
• After a wheel change, make sure pressures are exactly to spec before driving.
• Still showing with correct pressures? A sensor may have a flat battery — look up the code on autodtcs.com.

Frequently Asked Questions

How do I reset the tyre pressure light on a Subaru Legacy?

Set all four pressures correctly, then drive about 10 minutes above 40 km/h to relearn them.

Why won’t the warning clear?

Usually a tyre still below spec, or the learn drive wasn’t long enough.

Do I need a tool?

No for a normal reset; a tool is only needed if a sensor is replaced.

Does adjusting one tyre need a full reset?

Set all four correctly first, then do the learn drive so the baseline is right.

If the warning came on with other lights, decode the code on autodtcs.com.