A tyre can look normal and still be under-inflated. If the tyre pressure light is on but the tyres seem fine, start with a pressure gauge rather than the reset button.
If a tyre is visibly flat, damaged or losing air quickly, or the car’s handling changes, stop somewhere safe and arrange help. A dashboard reset cannot make a damaged tyre safe.
Check the pressures against the right figures
Use the manufacturer’s tyre-pressure label or handbook, including the correct setting for the load you are carrying. Do not use the maximum pressure printed on the tyre sidewall as the car’s target.
Check every road tyre when cold where possible. Michelin’s pressure-check guidance explains that driving warms the tyres and raises the reading. A check immediately after a journey can therefore give a different result from a cold check.
Record the readings before adjusting them. If one tyre loses pressure again, have the tyre, valve and wheel checked rather than repeatedly inflating it.
Is it a pressure warning or a system fault?
Notice what the lamp does when you start the car and read any accompanying message. Schrader’s TPMS guidance distinguishes a steady low-pressure warning from a lamp that flashes before remaining on, which can indicate a malfunction. Check your handbook because the display and sequence vary by vehicle.
A missing pressure reading or a message saying the monitoring system has failed deserves investigation even if a gauge confirms correct inflation. You still need manual pressure checks while the monitoring system is not working.
Not every car has a sensor inside each tyre
Direct TPMS measures pressure using sensors at the wheels. Indirect systems use wheel-speed information to detect changes consistent with pressure loss. Michelin explains the two approaches.
That distinction matters before anyone quotes for four new sensors. A car with an indirect system needs a different investigation from a car whose in-wheel sensor is no longer communicating.
What if it started after new tyres?
Tell the garage when the tyres were fitted and whether wheels were moved or replaced. The next check may involve inflation settings, the correct reset or relearn procedure, or the monitoring hardware fitted to that car.
Follow the vehicle’s handbook after setting the pressures correctly. There is no single reset-button location or driving time that works for every make. Do not repeatedly store a new baseline while a tyre is still losing air.
Will the warning fail an MOT?
A lit TPMS lamp is not automatically an MOT failure. The DVSA inspection manual distinguishes pressure-loss warnings from system malfunctions.
The TPMS check applies to M1 vehicles first used on or after 1 January 2012, with specified exceptions. A system that is malfunctioning or obviously not working is a major defect. If the cause of the lamp is unclear, the manual directs the tester to add advisory information. This does not remove the need to check the tyres themselves.
Tyre and warning-light checks in Medway
Bring your pressure readings and a description of when the light appears. At Medway Vehicle Services, we can start with a tyre inspection and discuss fault finding if the warning points beyond inflation.
Request a check before ordering parts. The aim is to establish whether the tyre is losing air, the system needs its correct setup procedure, or a fault needs repair.
