Could Tyre Pressure Monitoring Systems cause you to fail your MOT?

If your car was manufactured after 2014, it will have been fitted with a Tyre Pressure Monitoring System (or TPMS for short). If your car is a bit older than that, it may still have been fitted with a TPMS, as they were also introduced in 2012 to new model vehicles in Europe, before being included as a standard on all new cars in 2014.

Tyre Pressure Monitoring Systems utilise a pressure sensor, which is installed in each of your tyre’s air valves. It diligently monitors your tyres for any drop in pressure, letting you know when it senses any pressure imbalances or low pressure. You can find out more about how TPMS work on our Tyre Pressure Monitoring Systems information page.

Your car’s tyre pressure monitoring system is incredibly helpful, as it alerts you to issues in your tyres and prevents incorrect pressure levels going unnoticed for long periods. But, did you know that your TPMS could land you with an MOT failure?

The Tyre Pressure Monitoring System Legislation

On the 1st of January 2015, legislation was brought into effect which stated that a car displaying the TPMS warning light on the dashboard would result in an automatic MOT failure. This legislation was a positive step towards ensuring correct tyre pressure, and saw improvements in road safety as a result of greater tyre pressure awareness.

At the time that this legislation passed, any car registered after 1st January 2012 fitted with TPMS would fail its MOT if the TPMS warning light is displayed. However, MOT tests changed on the 20th of May 2018, where the government included different defect categories. Any defects found during an MOT service would fall under one of the following three categories - dangerous, major and minor.

When this was announced, if the car displayed a TPMS warning light on the dashboard, this would be marked as a minor defect. Defects that fell under this category would be considered to have no significant effect on the safety of the car or impact on the environment. They would be suggested to be repaired as soon as possible, but would not lead to an MOT failure.

Then, in June 2019, following the release of the government’s MOT inspection manual during May 2019, TPMS malfunction changed defect category to major. A major defect category is considered to affect the vehicle’s safety, put other road users at risk, or have an impact on the environment. This meant that the Tyre Pressure Monitoring System legislation had come full circle, and it once again can result in an MOT failure.

How to avoid a TPMS-related MOT failure

When looking at the system itself, the sensors are the most likely to need replacing. While TPMS sensors are designed to last for many years, it may be necessary to have your TPMS serviced occasionally to ensure it continues to work correctly - and to avoid an unnecessary MOT failure.

One of the most common TPMS sensor issues we see at our centres is battery failure. Each TPMS sensor is fitted with an internal battery, which on average should last 5 to 7 years. It’s worth noting, however, the more miles you travel, the quicker the battery will deplete, but on average, a sensor battery should last 5 to 7 years. TPMS sensor stems can also become corroded over time as they are open to the elements and take on everything the road throws at them.

When it comes to your car’s MOT and how your Tyre Pressure Monitoring System can impact the results, the simplest way to avoid a TPMS-related MOT failure is to keep an eye on your tyre pressures and manually check your tyre condition every month. If your tyre pressure drops by 6-7 PSI, your TPMS warning light will illuminate. Maintaining correct tyre pressure will prevent this from happening.

Replacing your TPMS sensor KwikFit

At Kwik Fit we believe in preventative maintenance, which is why we recommend that your TPMS sensors should be serviced every time a tyre bead is broken.

Should you require a new TPMS sensor, we can supply a cost-effective replacement sensor which clones your existing settings for a fraction of the price of a dealership replacement.

To find out more, contact your local Kwik Fit centre and ask about TPMS servicing.

We also offer a free tyre check at all of our centres if you have concerns about the condition of your tyres. For this service, please book online.