Tire pressure light: what it means and what to do

What a steady tyre pressure light means

A steady tyre pressure light means at least one tyre is significantly below its recommended pressure. The amber warning is usually a tyre-shaped symbol resembling a horseshoe with an exclamation mark inside; some vehicles also display a message or individual pressure readings. Amber means you need to act soon rather than ignore it until your next service. It does not, by itself, mean you must stop immediately wherever you are, but you should find a safe place to assess the tyres.

The warning comes from the tyre pressure monitoring system, usually called TPMS. Depending on the vehicle, it uses pressure sensors or information from the wheel-speed system to identify a possible loss of pressure. The light cannot tell you whether the cause is a slow leak, a sudden puncture or a temperature change. You need a pressure gauge and a visual check to establish what is happening. A tyre can look reasonably normal while still needing air.

What to do in the first minutes

Your first step is to reduce demanding driving and stop somewhere safe to inspect the tyres. Avoid hard braking, sharp steering and continuing at speed while you are unsure of their condition. Look for a visibly collapsed tyre, an object in the tread, sidewall damage or signs that the wheel has been struck. If the car pulls, vibrates or feels unstable, or you hear flapping, stop safely and arrange help rather than continuing to find an air pump.

Check pressures when tyres are cold and use the values on the door pillar label or in the owner's manual, not the maximum on the tyre sidewall. Check every road tyre, not just the one that looks soft, and inflate each to its specified value. Front and rear requirements may differ, and the label may give different values for different loads. If you have already driven, do not let air out of warm tyres merely to match a cold-pressure figure; check again when cold.

• Find a safe place away from moving traffic.
• Look for visible damage and listen for escaping air.
• Measure every road tyre with a suitable pressure gauge.
• Use the vehicle label or owner's manual for the correct pressures.
• Arrange help if a tyre is flat, damaged or will not hold air.

Why cold mornings and other causes trigger the light

Tyre pressure drops in cold weather, so the light often comes on during the first cold mornings of autumn. As the air inside the tyre cools, its pressure falls; a tyre that was already near the warning threshold may then trigger TPMS. The light may disappear after driving warms the tyres, but that is not proof that their cold pressures are correct. Check them cold rather than treating a warning that disappears as a problem that has fixed itself.

Other usual causes include a puncture, a leaking valve, a poor seal where the tyre meets the wheel, or a damaged wheel. Recent tyre work can also leave pressures incorrect or reveal a monitoring issue. On Georgia's uneven roads and mountain routes, tell the shop about any recent pothole or kerb impact. Do not assume every autumn warning is weather-related: a tyre that repeatedly loses pressure, especially when the others remain stable, needs a leak check.

Whether you can keep driving

You may be able to drive cautiously to a nearby place for a pressure check if the tyres look intact and the car behaves normally, but the light alone cannot establish that it is safe. Driving on a badly under-inflated tyre affects handling and braking and can damage the tyre. A visibly flat tyre, rapid pressure loss, exposed damage or changed handling means you should stop safely and seek help. Do not continue simply because the warning is amber rather than red.

Correct the pressures before a long journey, carrying a heavier load or heading onto mountain roads. Tbilisi traffic does not make an under-inflated tyre harmless: repeated driving still puts stress on it. If you have driven on a substantially soft tyre, ask a shop whether it needs inspection for internal damage even after reinflation. Air can restore the pressure reading without repairing damage already caused. If you cannot measure the pressure or judge the tyre's condition, arrange assistance instead of guessing.

How to reset the system and recognise a fault

Reset the tyre pressure monitoring system only after you have checked and corrected all tyre pressures. Some vehicles clear the light automatically after they detect the corrected pressures; others require a reset or calibration through a button or vehicle menu. Follow your owner's manual for the exact procedure and any driving conditions it specifies. There is no universal reset sequence for every car. Resetting with an under-inflated tyre can establish an incorrect reference on systems that learn a baseline.

A flashing TPMS light points to a sensor or monitoring-system fault rather than a straightforward low-pressure warning. It may flash first and then remain on, so note what it does when you start the car. Possible causes include an exhausted sensor battery, an incompatible or unrecognised sensor, or another system fault. Still check the tyres manually, because a monitoring fault does not prove their pressures are safe. Compare the symbol and message with your manual: ABS, stability-control and general warning lights have different meanings.

What a tyre shop checks

A shop checks actual tyre pressures, looks for leaks and damage, and investigates TPMS if the warning remains or flashes. Explain when the light appeared, whether it flashes at startup, and whether a particular tyre keeps losing air. The inspection may include the tread, sidewalls, valves, wheel condition and tyre-to-wheel seals. If a tyre has been driven while very soft, tell the shop so it can assess whether further inspection is needed rather than only topping it up.

For a monitoring fault, the shop can check which system your vehicle uses and whether the sensors communicate correctly or need registration. This is particularly useful with an imported used car whose wheel or sensor history is unclear. Ask for the diagnosis before agreeing to replacement parts. On Junto, you can find car services by service, price, place and next free time, then request an online booking for the shop to confirm. Suggested extra work can be sent by SMS link for your approval, with each line and its price visible before work starts.

• Does a tyre have a leak, damage or a sealing problem?
• Were the pressures checked against this vehicle's label?
• Is the warning caused by low pressure or a TPMS fault?
• Does any proposed sensor replacement need registration?
• What work is needed before the car is safe to drive?

Questions and answers