When tyres are correctly inflated, they grip the road surface more effectively and improve safety. If tyres are under or overinflated, however, it can pose a serious safety risk and increase your risk of collisions. Due to this, a low tyre pressure warning light is designed to alert you of this danger so that you can arrange for diagnostic testing and necessary repairs to be carried out.
Why is my low tyre pressure warning light on?
A vehicle’s tyre pressure monitoring system (TPMS) tracks the tyre pressures on your car or van and notifies you when they become too low (or too high). If your low tyre pressure warning light is on or flashing, it typically means that your tyres aren’t inflated correctly and could be dangerous. Due to the inherent safety risks associated with driving on under or overinflated tyres, it’s vital to check the vehicle’s tyre pressures, book a diagnostic test, and ensure the light is no longer illuminated.
What is the low tyre pressure warning light?
The low tyre pressure warning light tells you when the pressure inside the tyre is too low. An underinflated tyre experiences increased friction as more of the tyre’s surface is in contact with the road. The extra friction causes increased wear and tear and may even lead to a total tyre failure or blowout. Additionally, low tyre pressure reduces the vehicle’s grip on the road surface and makes it more difficult to control your car or van.
As incorrect tyre pressures pose a considerable safety risk, the low tyre pressure warning light is an important way of notifying drivers that there is an issue with the vehicle that needs to be resolved urgently.
What does it mean when the low tyre pressure warning light is flashing?
If the low tyre pressure warning light is flashing on the dashboard, the system is telling you that the pressure in one or more of the tyres is too low. On some vehicles, however, the low tyre pressure warning light acts as a general tyre pressure warning light and could indicate that the tyres are overinflated.
Depending on the make and model of your vehicle, the low tyre pressure warning light may flash briefly before remaining illuminated. Alternatively, it may continue to flash while the vehicle is in motion. In some cases, the light may remain illuminated when low tyre pressure occurs and begin to flash if the tyre pressure drops even lower.
How does the low tyre pressure warning light work?
All modern vehicles are fitted with a tyre pressure monitoring system (TPMS), which enables the car or van to track how inflated the tyres are. Some tyre pressure monitoring systems rely on sensors in each tyre to provide detailed information regarding the level of inflation. In other vehicles, existing systems, such as the sensors in the anti-lock braking system, track the tyres as they revolve (turn) and use these measurements to calculate the tyre inflation.
If the tyre pressure monitoring system records a tyre pressure that is too low, it triggers the low tyre pressure warning light. When this comes on, the driver can see that the tyre pressures are unsafe and take appropriate action, such as inflating the tyres and arranging a diagnostic test.
What are the common reasons the low tyre pressure warning light will come on?
Low Tyre Pressure
Unsurprisingly, the primary cause of the low tyre pressure warning light coming on is because one or more of the tyres are underinflated. By checking each tyre with a tyre pressure gauge, you can determine which one(s) are affected. Most vehicles state safe tyre pressure ranges on the door jamb or owner’s manual and, using this information, you can inflate the tyres to optimal pressure.
It’s worth noting, however, that some tyre pressure warning lights switch on when tyre pressures are too low or too high. Due to this, it’s important to check the tyre pressure before simply increasing it with more air.
Faulty Tyre Pressure Sensors
If you’ve checked the tyre pressures using a gauge and they are within the safe range but the low tyre pressure warning light remains on, this could be because the sensors are faulty. If your vehicle’s tyre pressure monitoring systems rely on sensors within the tyre itself, these may need to be replaced in order to remedy the problem.
Malfunctioning Tyre Pressure Monitoring System
Even when the sensors are functioning well, it’s possible that the tyre pressure monitoring system could develop a fault. It may interpret data from the sensors incorrectly, for example, or trigger the light at random intervals. By running diagnostics tests, a mechanic will be able to determine exactly what the fault is and how to remedy it.
Punctures and Slow Leaks
Tyre pressure gradually decreases over time, but it can drop at a faster rate if the tyre is punctured or has a slow leak. If the low tyre pressure warning light comes on relatively frequently, this could be because the tyre is damaged and allows air to leak out.
Is it dangerous to drive with my low tyre pressure warning light on?
Yes. Low tyre pressure reduces the vehicle’s stability on the road and makes it harder to control the vehicle. In addition to an increased risk of tyre failure, you are more likely to experience traffic accidents and collisions if your vehicle’s tyres are underinflated. Due to this, it’s essential to take action urgently when the low tyre pressure warning light is illuminated and/or blinking.
Is the low tyre pressure warning light flashing? If so, this could indicate a serious problem. Stop the vehicle when it’s safe to do so and seek further assistance.
What colour is the low tyre pressure warning light? Some vehicles’ warning lights flash yellow when there is a fault and red when there is an immediate safety risk.
How much does it cost to fix the low tyre pressure warning light?
Depending on the cause of the issue, resolving a low tyre pressure warning light issue can be below cost. If the tyres simply need to be inflated, for example, you can add air to the tyres at a local petrol station or garage and the light should switch off automatically. If the low tyre pressure warning light is illuminated because of something else, such as a malfunctioning tyre pressure monitoring system, the appropriate fix might be more complicated. By running a diagnostic test, you can determine why the low tyre pressure warning light is on, what fix is required and how much it’s likely to cost.
Will my car fail its MOT if the low tyre pressure warning light is on?
Yes. If a warning light relating to the tyre pressure monitor systems – such as the low tyre pressure warning light – is illuminated, your vehicle will fail its MOT. By having the issue investigated by a professional mechanic, however, you can remedy the issue and ensure the low tyre pressure warning light is functioning correctly.
About Fixter
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