A faulty Tyre Pressure Monitoring System (TPMS) is now an automatic MOT fail and is already catching motorists out. So how do you know if your car has it and how do you know if it’s working? Tyre safety association TyreSafe shares some advice
When driving, it is important that your vehicle’s tyres are properly inflated. If not then your braking, cornering, and all round safety could be compromised. What’s more, your car will use more fuel and will emit more CO2. To avoid these problems you should check your tyre pressures at least once a month, or before any long journey.
Most cars in the UK are now fitted with tyre pressure monitoring systems (TPMS). On most TPMS systems, sensors attached to the wheel monitor the pressures inside your tyres and if the pressures falls below a certain level, then the system will let you know via a warning sign on the dashboard.
If your TPMS light comes on you should manually check your tyre pressure at the first safe opportunity against the manufacturers recommended settings. If you are unable to do this yourself, either call your roadside assistance provider or call into your nearest tyre fitting centre.
MoT failure
As of 1 January 2015, a car displaying a TPMS fault when submitted for its MoT will result in a test failure. To avoid this, TyreSafe, the UK’s tyre safety association, have launched a campaign to increase awareness of TPMS, including a simple video to help motorists understand the safety features of this technology.
“Although TPMS technology has been around for decades, its inclusion in new model vehicles has only been mandated in Europe since 2012 and on all new cars since 2014. This led to a gradual introduction into the market over a period of years and with little or no fanfare to help educate motorists,” noted Stuart Jackson, chairman of TyreSafe. “Our members have been telling us that they’re encountering a lot of customers who either aren’t aware of how these systems work (and need to be maintained) or just see them as an expensive luxury rather than the crucial safety feature they are.”
TPMS servicing
Two types of TPMS systems are fitted on cars today. Direct systems use radio sensors mounted inside of each wheel to measure the tyre inflation pressures. Indirect systems utilise the vehicle’s existing ABS sensors to measure and compare the rotational speeds of the tyres, which are affected by their pressures. Both types work with the vehicle’s main Electronic Control Unit (ECU) to alert the driver via dashboard warning lights to any pressure loss or variance issues.
To ensure your TPMS system continues to operate properly and reduce the likelihood of an MOT failure, it may be necessary to have the system serviced occasionally. TPMS sensors are designed to last for many years and miles, however, after a certain period, the sensor’s internal battery will run out meaning a replacement is needed.
In addition, sensors can become faulty or fail completely as a result of weather damage, corrosion or accidental damage caused when changing tyres. To ensure the sensor remains in good condition, many manufacturers recommend replacement of the valve cap and core components every time a tyre is changed.
When replacement TPMS sensors are fitted to your vehicle, your tyre fitter may need to programme the new component to the car using specialist diagnostic equipment. If your TPMS sensor does develop a fault, under no circumstances should this be removed and replaced with a ‘standard’ non-TPMS type valve. Removing the sensor will not only reduce your safety on the road, it will also result in your car failing its MoT.
Manual checks
While the benefits of TPMS are widely recognised, it is important that they are not seen as a replacement for regular manual tyre safety checks. Pressures should be tested at least once a month or before any long journey, when the tyres are cold using an accurate and reliable pressure gauge.
When checking pressures, it is advisable to also give the rest of the tyre a thorough visual inspection as well as ensuring the tread is not excessively or unevenly worn.