Tyre Pressure Warning Light On? What It Means & What To Do in Ashford TW15
The tyre pressure warning light (TPMS) appearing on your dashboard means one or more of your tyres is significantly under-inflated. In most cases it's not a crisis but you should act on it promptly. Here's what it means, what causes it, and what to do.
What is the tyre pressure warning light?
The TPMS (Tyre Pressure Monitoring System) warning light looks like a cross-section of a tyre a horseshoe shape with an exclamation mark inside. It has been mandatory on all new cars sold in the UK since November 2014, and it triggers when tyre pressure in one or more wheels drops approximately 25% or more below the vehicle's recommended level.
Why has the tyre pressure light come on?
There are several possible causes, from harmless to urgent:
Temperature drop
Tyre pressure drops by roughly 1 PSI for every 10°C fall in temperature. On a cold morning after an overnight temperature drop, the TPMS light may come on and then go out once the tyres warm up from driving. If it goes off after a few miles, check your pressures when the tyres are cold and top up if needed this is likely a borderline pressure issue that the cold has pushed over the threshold.
Slow puncture
A small nail, screw, or road debris embedded in the tread can cause a slow, gradual pressure loss that takes hours or days to become noticeable. If the light has come on and doesn't go away, inspect each tyre visually and check the pressures. A slow puncture usually shows one tyre notably lower than the others.
Valve fault
The valve stem the small protrusion you attach a pump to can degrade over time or get damaged, causing a slow leak. This is inexpensive to fix when you have tyres fitted.
Faulty TPMS sensor
Each wheel has a small sensor that communicates with the car's system. Sensors have batteries that typically last 5–10 years. If a sensor battery fails or the sensor is damaged (for example, after a pothole), the light may come on even when pressures are correct. If you've inflated all four tyres to the correct pressure and the light stays on, a faulty sensor is the likely cause.
Is it safe to drive with the tyre pressure warning light on?
It depends on how low the pressure is:
- Slightly low (light just came on): Drive carefully to the nearest garage or petrol station and check pressures. Avoid motorway speeds.
- Significantly low or flat: Do not drive. A severely under-inflated tyre can overheat, delaminate, and fail causing a blowout. Pull over safely and either inflate the tyre or call for assistance.
Check the pressures, don't just reset the light. Some drivers reset the TPMS without checking the actual pressures. The light will come back on and if there's a slow puncture, the tyre will continue losing pressure. Always check the pressure with a gauge first.
What should I do when the tyre pressure light comes on?
- Don't panic. Slow down and avoid sharp manoeuvres.
- Check all four tyre pressures at a petrol station or using a portable gauge. Your vehicle's recommended pressures are in the handbook or on a sticker inside the driver's door jamb.
- Inflate any low tyre to the correct pressure. If pressure restores normally and there's no damage, the light should go out within a few miles.
- If one tyre is much lower than the others, or if you can see or hear an obvious puncture, don't drive on it. Come to us at Salek and we'll inspect and repair or replace it.
- If the light stays on after inflating correctly, there may be a faulty sensor or a continuing slow leak. Book in for a check.
How to check your tyre pressure
For a full guide to checking and inflating tyre pressure correctly, see: How to check tyre pressure.
Tyre pressure concern in Ashford? Come in or call us
If you're unsure whether a slow puncture, faulty sensor, or something else has triggered the light, drop in to 32–34 Feltham Road, Ashford TW15 1DH. We'll check your pressures, inspect the tyres, and sort it quickly.