The TPMS warning light, a horseshoe shape with an exclamation mark, tells you a tyre is significantly under-inflated, or that the monitoring system itself has a fault. It's a legally important system: on cars first used from 1 January 2012, a malfunctioning TPMS is an MOT failure.
What TPMS does
Tyre Pressure Monitoring Systems alert you when a tyre loses pressure. There are two types: direct systems use a sensor in each wheel to read actual pressure, while indirect systems infer low pressure from wheel-speed data via the ABS.
Steady light vs flashing light
- Steady light: usually a genuinely low tyre. Check and correct all pressures.
- Flashing then steady: often a system fault, such as a failed sensor or one that needs reprogramming after a tyre change.
What to do
- Check all four pressures when cold and set them correctly.
- Look for a slow puncture if one tyre keeps dropping.
- Remember cold weather can trip the light, top up and it may clear.
- If the light stays on after correct inflation, a sensor likely needs service.
Sensors and tyre changes
Direct TPMS sensors have batteries that eventually die, and they sometimes need reprogramming after a new tyre is fitted. We handle TPMS when we fit tyres at your location across London and Birmingham. Book a check.
