The horseshoe-with-exclamation light means a tyre may be low. How to check, how to reset, and the MOT rule for cars from 2012.
Looking for more detail? Our full guide covers this topic in depth, with step-by-step advice and sources.
The tyre pressure monitoring system thinks one or more tyres are under-inflated. Flashing then steady usually means a system fault.
What it looks like
A cross-section of a tyre with an exclamation mark. Colour: Amber.
Common causes
- A slow puncture
- Pressure drop in cold weather
- A failed sensor battery (direct systems)
- System not reset after inflating tyres (indirect systems)
What to do
- Check all four tyre pressures when cold against the figures in the door frame or handbook.
- Inflate and follow the handbook to reset the system.
- If one tyre keeps losing air, have it checked for a puncture.
Can I keep driving?
Yes, carefully, to the nearest place you can check pressures, unless a tyre is visibly flat.
MOT
For cars first used from 1 January 2012, a TPMS malfunction is an MOT fail.
Symbols vary slightly between makes. Always check your owner's handbook. General guidance only; if in doubt, call your breakdown provider.
Sources and further reading
Facts checked on 20 October 2026. Spotted an error? Tell us and we will correct it.