Tyre pressures are now monitored automatically on all passenger vehicles manufactured after November 2014 by a device known as Tyre Pressure Monitoring System (TPMS) but many older cars also have them fitted. While they are a terrific safety feature, helping the driver know their tyre pressures when they need it most – while on the move – they should not be considered a ‘silver bullet’ to ensuring the vehicle’s tyres are in good condition. Manual checks are still very important.
There are two different types of TPMS. One has sensors mounted on the wheel inside the tyre and sends a signal to the control box updating it in real time with the current pressure, while the other calculates pressure using the Anti-lock Braking System (ABS). You’ll know the difference when you come to adjust your tyre pressures as with the latter system you need to press a button to confirm to the controller that the pressures are set correctly.
Even though both are reliable systems, failures can occur. For instance, the battery in sensors can run out and could potentially leave you unaware you are losing pressure. That’s why they need to be checked and if you see the TPMS light on your dashboard you should have it inspected immediately.
Should a TPMS valve need replacing, never replace it with a standard valve as the system won’t work as it should. That’s not only dangerous but also leaves you liable to fail your MoT, as a fully-functioning TPMS is now required if it was original equipment on a vehicle manufactured after 1st January 2012.
So, to be sure your TPMS is working, you need to carry out regular manual checks – including the air pressure of your vehicle’s tyres. Always use an accurate gauge when you’re checking pressures which can commonly be found for your vehicle:
Inside the vehicle handbook
Inside the fuel filler flap
On a placard located in the door shut
It is not just pressures that need to be checked of course, as drivers should take care to ensure there are no visible cuts, lumps or bumps in the tyre. While you’re checking, use a 20p to check the tread depth is over the minimum legal limit of 1.6mm. Simply insert the 20p at various point across the diameter and circumference of the tyre and look to see if you can see the border of the 20p at any point. If you can, or you’re unsure, have them checked by a tyre specialist.
Find out more on TPMS and tyre safety at www.tyresafe.org