The tyre pressure warning light is an amber symbol shaped like a cut through tyre, a horseshoe with an exclamation mark inside, and it means at least one tyre has dropped well below its set pressure or the monitoring system has a fault. Slow down, stop when it is safe, and check every tyre with a gauge.
Owners often roll into the shop days after the light came on, thinking it was a glitch. Sometimes it is. But often there is a nail in the tread, and by then the sidewall has been flexing hot for 100 km. This page explains the symbol, what the light patterns mean, and how to reset it once the cause is fixed.
At a glance
- SymbolAmber horseshoe shaped tyre section with an exclamation mark inside
- Steady lightAt least one tyre is well below its set pressure
- Flashes, then stays onOn many cars this points to a system or sensor fault
- First stepSlow down, stop safely, check all tyres with a gauge
- ResetSet cold pressures, then use the button or menu and drive
- Not the same asThe fog lamp symbol or decorative valve cap lights
Recognising the tyre pressure symbol
The tyre pressure symbol shows the cross section of a tyre, flat at the bottom where it meets the road and open at the top, with an exclamation mark in the middle. It glows amber or yellow. Some cars also show a small car outline with the low tyre marked, or a message on the instrument screen with each tyre's figure.
Do not confuse it with the brake warning, which is usually a circle with an exclamation mark and brackets on each side, often red. Also do not mix it up with the fog lamp light, which looks like a lamp with wavy lines through its beam. Still in doubt? Every owner's manual carries a chart of the dashboard symbols.
What a steady low tyre pressure warning light means
A light that comes on and stays on while driving usually means the low tyre pressure warning light has been triggered by a real drop. The system is set to warn only when a tyre is clearly below its normal figure, not when it is a psi or two out. So by the time it lights, the tyre is already noticeably soft.
A light that appears on a cold morning and fades after a few kilometres often means the pressures are just at the edge. Cold air shrinks, so the reading dips overnight and rises as the tyres warm. Top all four up to the sticker figure and the light should stay off.
When the tyre pressure light flashes
On many cars, a tyre pressure indicator that blinks for about a minute after ignition and then glows steadily is flagging a monitor fault, not missing air. Common causes include a sensor with a dead battery, a sensor damaged during a tyre change, or a wheel fitted without a sensor, such as a spare. Your manual will say exactly what the flashing pattern means on your car.
Still check the pressures by hand, because a faulty monitor cannot warn you about a real leak. Then have a tyre shop or service centre scan the system.
What to do when the warning comes on
- Do not brake hard or swerve. Ease off and keep the steering straight.
- Stop where it is safe, away from traffic, with hazard lights on.
- Look at each tyre. If one is clearly flat, change to the spare or use the repair kit.
- If none look flat, check all of them with a gauge. A tyre can lose a lot of air and still look normal.
- Inflate to the sticker figure at the nearest pump or with a portable inflator.
- If one tyre read far below its partners, get it dunked or inspected for a puncture.
How to reset the tyre pressure warning light
First set every tyre, cold, to the figure on the door sticker. Resetting with wrong pressures teaches the system the wrong baseline. Then follow your car's method:
- Reset button: some cars have a button under the dashboard or near the steering column. With the ignition on, hold it until the light blinks, then release.
- Instrument menu: many newer cars have a tyre pressure option in the settings menu to store the new pressures.
- Automatic: on many direct systems the light simply turns off after a short drive once the pressures are correct.
After a reset, most systems need a drive to relearn. Manuals vary, with some asking for around 20 minutes of driving at steady speed. If the light returns soon after, there is a slow leak or a fault. Our TPMS guide explains how the two kinds of system learn pressures.
Tyre valve cap light and other look-alikes
Some owners fit LED valve cap lights that glow as the wheel turns. These are decoration only and do not measure pressure. A different product, the valve cap pressure sensor, does report pressure to a small display or phone. Both replace your normal caps, so make sure any cap you fit still seals the valve against dust and water.
If your car has no factory warning system at all, a regular hand check with a gauge is your only warning. Our step by step check and the guide to gauges cover that.
Keeping the light off
Most warnings I see are avoidable. Check pressures cold every two weeks and top up before they drift to the trigger point. Keep valve caps on. After a puncture repair, tell the shop the car has sensors so they handle the wheel with care. When you fit new tyres or alloys, ask whether the sensors move across. For figures by vehicle, see car tyre pressure or the main tyre pressure page.
Questions owners ask
Can I drive with the tyre pressure light on?
Only far enough to check and inflate the tyres safely. A badly under-inflated tyre overheats and can fail, especially at highway speed. If a tyre is flat, change it or use the repair kit before driving on.
Why is the tyre pressure light on but my tyres look fine?
Radial tyres hide low pressure well. Check each one with a gauge. When all four match the placard, suspect a monitor awaiting relearn or a failing sensor.
How to reset tire pressure light after filling air?
Set all tyres cold to the sticker figure, then press the reset button or use the instrument menu if your car has one, and drive for a while. Some cars clear the light by themselves once pressures are right.
Does the light come on for the spare tyre?
Usually not, as most spares have no sensor. If you fit a spare without a sensor, many direct systems will show a fault light until the original wheel goes back on.
Is the tyre pressure light the same as the TPMS light?
Yes. The horseshoe with an exclamation mark is the tyre pressure monitoring system warning. Some cars add a separate TPMS text or a flashing pattern for faults.
Why does the light come on in the morning only?
Overnight cooling lowers the pressure, pushing a slightly low tyre below the warning level. As the tyre warms on the road, pressure rises and the light goes off. Top up to the correct cold figure.