TPMS
Since November 2014 it has been mandatory for all cars registered since then to have a form of TPMS (Tyre Pressure Monitoring System) installed.
The light can be triggered by several factors, a 1puncture. Two or more tyres having incorrect pressure. Temperature (too hot and the tyre expands and the system thinks the tyre is overinflated, cold has the opposite effect and the system can think the tyres are underinflated)
There are two types of TPMS systems:
1: Indirect, where the tyre pressure is calculated by the vehicles ABS system
2: Direct, where a sensor is fitted in the wheel and communicates with the vehicles ECU to calculate the tyre pressure.
With a direct system (usually signified, but not always, with a metal valve fitted in the wheel) parts can corrode or wear out. We carry hundreds of parts to replace most types of valve and even programable sensors to replace worn out of faulty ones.
We have even learnt, over time, how to reset most systems as heaven knows why they haven’t been standardised across all manufacturers!