Your Tyre Pressure Monitoring System light warns you of under-inflation. Learn why it comes on, how to reset it, and when you need a new TPMS sensor fitted.
Since 2014, all new cars sold in the UK are required to have a Tyre Pressure Monitoring System (TPMS). When that horseshoe-with-exclamation-mark icon lights up on your dashboard, it means one or more tyres are significantly under-inflated — or a sensor has failed.
What Triggers the TPMS Light?
Common causes include:
- A tyre that's 25% below its recommended pressure
- A slow puncture gradually deflating a tyre
- Cold weather causing tyre pressure to drop naturally
- A faulty or dead TPMS sensor battery
- A new tyre fitted without programming the replacement sensor
How to Reset the TPMS Light
If your tyre pressure was genuinely low, inflate all tyres to the correct PSI and drive for a few minutes at over 30mph — the system should self-reset. If the light stays on after correcting pressure, the sensor itself may need attention.
When Do TPMS Sensors Need Replacing?
TPMS sensor batteries are sealed units and typically last 5–10 years. When a battery dies, the sensor must be replaced entirely. Sensors must also be replaced (or reprogrammed) when new tyres are fitted, as the sensor service kit — valve, seal and cap — should be renewed at every tyre change.
Totally Mobile Tyres carries TPMS sensors and programming equipment on every van. We can replace and re-programme sensors on-site at no extra call-out cost.
Don't ignore a TPMS light — under-inflation increases tyre wear, fuel consumption and blowout risk significantly.
