Complete guide to TPMS: Avoid MOT failure due to faulty TPMS

The recent years have seen huge developments in the automobile industry. One of them is the TPMS, also known as the Tyre Pressure Monitoring System. It is a highly crucial invention to ensure tyre safety for every car owner. The technology has been in use since 1986, but the current EU rules made TPMS fitting a standard for all cars. This goes on to show the usefulness and need of this safety feature. The importance of this invention in road safety has also made it vital for the MOT. However, most car owners feel that the sensors cause more headache during the annual check. To avoid such issues, follow this guide. Find out more about the TPMS system, how it affects the MOT, and the right time for a replacement.

The basics of TPMS.

Understanding the system is crucial to take the appropriate steps for its maintenance. The TPMS is a system to check the pressure or loss of pressure in tyres and to alert the driver accordingly. This is a continuous process, and the driver receives an alert if there is any drop in the tyre pressure below a certain level. Since inflation is a crucial aspect of tyre and road safety, this monitoring system becomes an important component. 

 

For automobiles, the TPMS comes in two types: 

 

• Direct System: In this system, the pressure of each tyre is measured directly. This information is then sent to the control unit of the vehicle. 
• Indirect System: In this system, tyre pressure is measured indirectly. For this, it uses the vehicle’s ABS sensors to measure and compare the rotational speeds of the tyres and vibrations. 

The information collected from both of these systems are ultimately sent to the vehicle’s primary Electronic Control Unit (ECU). This notifies the driver of any loss in tyre pressure or other issues using the dashboard warning lights.
 

The importance of using TPMS. 

 

The air pressure of a tyre determines its performance. Every aspect of the tyre’s functions is related to the air pressure within it. The speed capacity, maximum weight, vehicle handling, wear and damage, and overall safety and comfort, all depend on appropriate pressure. Underinflation and overinflation of tyres is known to have a negative impact on the performance. Underinflation causes increased fuel consumption and emissions. Overinflation, on the other hand, can lead to tyre burst. To keep the pressure in check, the TPMS system is crucial. It allows you real-time information on the pressure and alerts you if it decreases below a certain safe level. 

 

As of 2014, the EU has made it compulsory for fitting the TPMS in all passenger cars. Plus, there needs to be routine checks and maintenance for the system. Following this, the UK stated new regulations, applicable from January 1, 2015. This included that damaged or malfunctioning TPMS sensors could lead to an MOT failure.
 

Common problems of the TPMS. 

 

The TPMS is a vital sensor system, and malfunctions are common too. Here are the most commonly found problems in the system that could also cause MOT failures: 

 

Battery issues: A common problem with the TPMS sensor is battery failure. Every sensor has an internal battery which can last up to 100,000 miles. Although the battery depletion depends on the amount of miles you travel, it should still last for up to 5 to 7 years. Usually, the battery is found in a sealed sensor casing, hence repair is almost impossible. So, you will need a TPMS replacement in Harrow. 

 

Valve stem problems: The sensor as a whole is usually protected by the safety of the tyre’s structure. However, the valve stem remains a weak point. The stem remains outside of the tyre and the rim. Hence, it is prone to damage from the outside environment. For example, salt is used to grit the roads. This is particularly damaging and could corrode the stem, making it brittle. A damaged valve stem means you would have to replace the whole sensor. 

Correct functioning of the TPMS. 

 

How do you know that the TPMS is functioning correctly? There are a few capabilities that the sensor should possess. An expert will check if your TPMS is functioning correctly based on these functions: 

• It should warn you about loss of pressure in an individual tyre. This should be done within a 10 minutes time-frame. The alert is applicable on a 20% lower air pressure at 1.5 bar. 
• It should warn you about loss of pressure in all the four tyres. This also includes a sudden or gradual loss. The alert is sent if the pressure is 20% lower than the operating pressure at 1.5 bar. 
• It should be able to determine the pressure loss at speeds of 40 km/hr to the maximum driving speed of the vehicle. 
• It should be capable of transferring data on 434 MHz.

The necessity of TPMS replacement.

If you are wondering whether a TPMS replacement is necessary, it is! Firstly, the sensor is a lawful requirement for all vehicles, from 2014. If your vehicle has no sensor fitting, you could be fined or punished. Then, the MOT also requires a completely functioning sensor. Without it, your car could fail the test, and driving without the MOT certificate means a fine of £1000! 

 

Ultimately, your safety depends on the tyre, and a tyre’s optimal functioning depends on the air pressure. Hence, a TPMS is important for maintaining your tyre’s pressure and your safety. Invest in a timely TPMS replacement, if there is a malfunction. Ensure a safe and comfortable journey every time!