How to check your tyres and respond to the warning light

An amber tyre pressure warning light needs prompt action, not guesswork. If you’re wondering what to do when the tyre pressure warning light comes on, slow down, pull over somewhere safe and check every tyre. Use the recommended pressures in your vehicle handbook, on the driver’s-side doorpost or inside the fuel filler flap. Inflate any under-inflated tyre to the recommended level. If a tyre is completely flat, don’t drive on it.

A warning can point to pressure loss or a puncture, but a temperature change or sensor fault can also keep the light on. You may already know that tyres need the correct pressure to handle safely, but the dashboard alert doesn’t always reveal the cause. This guide explains what the warning means, how to check your tyres and reset the system, and when a persistent or flashing light needs further attention. You’ll also learn how colder weather affects pressure and what to do if your tyres seem correctly inflated but the warning remains.

What is the tyre pressure warning light?

1. Identify the amber dashboard icon as a tyre pressure alert. A vehicle’s tyre pressure monitoring system (TPMS) tracks air pressure and warns of pressure loss, under-inflated tyres or a possible puncture. Direct TPMS systems usually trigger when pressure drops past a set parameter, often around 25%. The threshold varies by vehicle, so the warning light is not a pressure gauge.
2. Act promptly when the warning light comes on. Reduce speed, find a safe place to stop and check for a visibly flat tyre or damage. Check your tyres before driving on. An amber TPMS light means action is needed, even if the vehicle still feels normal. If the car pulls to one side or handles differently, stop somewhere safe.
3. Use a tyre pressure gauge to check all four wheels, not only the tyre that looks low. Check the pressure when the tyres are cold; they can be measured cold after standing for at least 3 hours. Compare each reading with the vehicle’s recommended pressure, then inflate any tyre that is below its specified level.
4. Set each tyre to the vehicle manufacturer’s recommended pressure, not a generic figure. Find the correct values in the handbook, on the driver’s-side doorpost sticker or inside the fuel filler flap. Check whether the listed pressures differ for front and rear tyres or depend on the vehicle’s load. Use the figures for your specific car and driving conditions.
5. Check tread and tyre condition separately from the TPMS reading. UK tyres must meet legal tread-depth and condition requirements and must not have dangerous damage. The warning light monitors pressure; it doesn’t confirm that tread is adequate or that a sidewall is free from cuts, bulges or other defects. Inspect the visible tread and sidewalls before driving.
6. Look for signs of a puncture or rapid pressure loss, such as a tyre that appears deflated, a nail or sharp stone in the tread, or a sudden change in handling. A puncture can trigger the TPMS warning even when the pressure loss isn’t immediately obvious. Don’t drive on a completely flat tyre. Use a spare or arrange roadside assistance.
7. Reset the TPMS only after checking and correcting every tyre’s pressure. Store the readings using the vehicle menu or Set button; the reset control is often beneath the steering wheel. Drive for 10-20 minutes to allow recalibration. If the light stays on, a slow puncture or faulty TPMS sensor may be responsible. If it flashes and remains lit, check pressures and arrange an inspection.

How temperature changes affect tyre pressure

1. Recheck your readings when colder weather brings on a dashboard alert. Tyre pressure changes by about 1 psi for every 10°F change in temperature. A colder reading can therefore trigger the TPMS even when a tyre has no puncture. The pressure change affects the air inside the tyre, not necessarily its condition. Still inspect the tyre, because a temperature-related warning and a slow leak can appear at the same time.
2. Allow for the scale of the temperature drop before deciding what the warning means. A 30°F fall can lower tyre pressure by about 3 psi. That change may be enough to bring a tyre below its vehicle’s recommended pressure and trigger the alert. The dashboard shows that pressure needs attention; it doesn’t tell you whether cold weather or air loss caused it. Check each tyre rather than assuming the cold affected them equally.
3. Check tyre pressure when the tyres are cold and compare each reading with the car’s specified values. A reading taken after driving may be higher because the tyres have warmed up. Don’t release air from a warm tyre to match a cold-tyre figure. If the cold reading is low, inflate to the vehicle’s recommended pressure, then watch whether the warning clears. Use the same pressure units shown on the vehicle information.
4. Notice whether the light appears after a sudden cold snap or returns in similar conditions. Temperature-related changes may affect all four tyres, but differences in starting pressure can mean one tyre reaches the warning threshold first. An indirect monitoring system may detect changes through wheel behaviour rather than measuring air pressure directly. It can still alert you, but a physical pressure check remains necessary.
5. Consider sensor faults if the warning persists. Cold weather can change tyre pressure, but it doesn’t explain every flashing light or repeated alert. A TPMS sensor fault may need attention, and a sensor battery issue is different from a tyre losing air. Don’t search beneath the steering wheel for a reset control before correcting the pressures. Record the readings and the conditions when the alert appears to help identify a recurring pattern.

Driving with the warning light on

1. If you’re deciding what to do when the tyre pressure warning light comes on, reduce speed and avoid harsh braking or sharp steering. In the UK, you can legally drive with the warning light on, but proceed cautiously and only as far as needed to reach a safe stopping place. The alert means a tyre may be under-inflated. Continuing at normal speed can add strain if pressure is falling.
2. Choose a safe place to stop, away from moving traffic, before inspecting the vehicle. Check whether a tyre looks visibly low, damaged or completely flat. If the car pulls to one side or handles differently, stop as soon as it’s safe. A sudden change in steering or stability is a reason not to continue your journey.
3. Don’t drive on a completely flat tyre. The wheel can damage the tyre further, and the vehicle may become difficult to control. Fit a spare if you can do so safely, following the vehicle manufacturer’s instructions. If there’s no usable spare, arrange roadside assistance rather than attempting to reach a garage on the flat tyre.
4. If no tyre is visibly flat, check the pressure in all wheels before deciding whether to continue. Use a gauge and compare each reading with the manufacturer’s recommended figures. A tyre can look inflated yet still be below its correct pressure. If a reading is low, inflate it before driving further, then watch for another warning.
5. Look for evidence of a puncture, such as a nail in the tread, a cut or pressure that drops again after inflation. Don’t remove an embedded object while the tyre is fitted. If the warning returns or the tyre loses pressure again, treat the problem as unresolved. A puncture may need repair or replacement before normal driving resumes.
6. After the warning light goes out, continue carefully and check the tyre pressures frequently. The light switching off doesn’t prove that a slow leak has stopped. For example, a tyre inflated at the roadside may lose air again during the next part of your journey. Stop safely if handling changes or the warning returns.
7. Knowing what to do when the tyre pressure warning light comes on also means deciding whether the tyre is safe for the next part of your journey. Correct pressure and normal handling may allow cautious onward travel, but visible damage, a flat tyre or repeated pressure loss needs attention first. Keep the vehicle handbook handy for pressure and spare-wheel instructions. Don’t rely on the dashboard alone to assess tyre condition.

Faulty sensors and sensor batteries

1. Compare the warning with actual tyre readings before blaming a sensor. If every tyre is at the vehicle’s recommended pressure but the TPMS light remains on, a slow puncture or system fault may be responsible. Record the readings and note whether the warning stays steady or flashes. This gives a clearer starting point for diagnosis than the dashboard symbol alone.
2. Pay attention to a flashing warning that remains lit while driving. This pattern may indicate a TPMS sensor fault rather than a straightforward pressure alert. It doesn’t prove the tyres are correctly inflated, so check each tyre with a gauge first. If the readings are correct and the light continues, the sensor or another part of the TPMS system may need inspection.
3. Consider sensor battery age as one possible cause. A typical tyre-pressure sensor battery lasts about 10 years before the sensor needs replacing. In direct TPMS systems, the battery is usually non-replaceable, so a depleted battery means replacing the sensor itself. Age can point towards this fault, but a pressure check still matters because an underinflated tyre can trigger a genuine warning.
4. Distinguish an intermittent alert from a confirmed sensor problem. Temperature changes can lower tyre pressure, while a faulty sensor can prevent the system from reporting pressure correctly. Check and correct the pressures first, then see whether the TPMS warning returns. If it reappears despite correct readings, repeated resetting won’t repair a failed sensor or restore its battery.
5. Arrange a sensor inspection when correcting the pressure doesn’t clear the warning. The TPMS Sensor Replacement Service addresses a failed sensor; replacing it is not the same as inflating a tyre or repairing a puncture. Identifying the fault helps determine whether the sensor needs attention, rather than assuming every warning means the same component has failed.
6. Ask for the sensor’s condition to be considered when tyres are changed. Tyre-pressure sensors can be reused with new tyres if they’re still working well. A working sensor doesn’t need replacing simply because a tyre is being renewed. If its battery has run down or the sensor has failed, replacement may be needed to restore the TPMS system’s pressure monitoring.
7. Keep checking tyre pressure even after a sensor fault is identified. A failed sensor can affect the warning system, but it doesn’t prevent the tyre itself becoming under-inflated. Use the vehicle’s recommended pressure as your reference and respond to visible damage or a changing reading. Treat the dashboard alert and the physical condition of each tyre as separate checks.

What to do when the tyre-pressure warning light comes on

1. If you’re deciding what to do when the tyre pressure warning light comes on, ease off the accelerator and reduce speed first. Avoid harsh braking or sharp steering. Find a safe place to stop, away from moving traffic, before inspecting the vehicle. If the car’s handling changes or it pulls to one side, stop as soon as it’s safe. Don’t ignore a change in steering simply because the dashboard alert is amber.
2. Look at all four tyres before driving further. A tyre that appears flat, damaged or visibly lower than the others needs immediate attention. Use the vehicle’s spare if it’s safe to fit, following the handbook instructions, or arrange roadside assistance. Driving on a flat tyre risks further damage and can affect control.
3. Check every wheel with a pressure gauge, not just the one that looks low. Compare the readings with the manufacturer’s recommended values in the manual, on the driver’s-side doorpost sticker or inside the fuel filler flap. Check the front and rear figures separately. A tyre can look inflated but still be below the correct pressure for that vehicle.
4. Take readings when the tyres are cold for a useful comparison. Cold-tyre pressure can be measured after the vehicle has been standing for at least 3 hours. If you’ve just driven, don’t release air simply to match a cold-pressure figure. Inflate any low tyre to the manufacturer’s recommended level, then check all wheels again.
5. Inspect the tread and sidewalls for a nail, sharp stone, cut or bulge. A puncture may cause the pressure to fall again after inflation, so don’t mistake a temporary improvement for a repair. If the pressure is still incorrect or the tyre is damaged, don’t continue as though the issue is resolved. Arrange repair or replacement before relying on the tyre.
6. Use the vehicle menu or Set button to store the corrected pressures if the manufacturer’s instructions require a TPMS reset. Then drive for 10-20 minutes so the tyre pressure monitoring system can recalibrate. The reset records the new readings; it doesn’t fix a puncture or faulty sensor. If the warning remains, or returns during that drive, stop and have the cause examined.
7. Knowing what to do when the tyre pressure warning light comes on also means acting on a persistent alert rather than repeatedly resetting it. Correct pressures followed by a continuing warning can point to a slow puncture or TPMS fault. If you can’t safely continue, arrange mobile tyre assistance for help with a damaged or deflated tyre. Keep the pressure readings and any warning behaviour ready to explain.

Mobile Tyre Fitting Essex: Mobile Tyre Fitting

Mobile Tyre Fitting Essex can help when a warning leads to a puncture, damaged tyre or pressure loss that makes driving unsafe. Its Mobile Tyre Fitting and 24-Hour Emergency Tyre Fitting services bring tyre assistance to your location, so you don’t need to drive on a flat or compromised tyre.

If the tyre may be repairable, Mobile Tyre Fitting Essex provides a Puncture Repair Service on site in Essex and nearby areas, including Essex, Kent, Cambridge and London. A persistent warning after pressure checks may instead point to a sensor issue, which needs a different solution. Choose the service that fits what you’ve found, and share your tyre readings and warning symptoms when arranging help.

For assistance with a tyre problem, contact Mobile Tyre Fitting Essex.

Be ready for the next warning

Make the next pressure check easier before setting off. Keep your vehicle handbook accessible, know where the recommended pressure label is, and carry a reliable gauge if you have one. These preparations help you act promptly if a dashboard alert appears away from home. If a TPMS warning appears, begin with a safe stop and a clear assessment rather than resetting the system straight away.

Pay attention to patterns over time. If the same tyre repeatedly loses pressure, or the warning returns after a correction, arrange help rather than treating it as a routine dashboard nuisance. Avoid continuing on a damaged or deflated tyre. A clear description of what happened and which tyre is affected can make it easier to explain the problem when arranging assistance.

For support with a tyre issue, contact Mobile Tyre Fitting Essex. Take the next step calmly and keep your journey safe.

Frequently Asked Questions

Do TPMS sensors need replacing?

A TPMS sensor needs replacing when it has failed or its internal battery has run down, not simply because a tyre is being changed. On direct systems, the sensor battery is usually non-replaceable, so the sensor itself must be renewed. If the sensor is still working well, it can be reused with a new tyre. Have a recurring fault diagnosed before assuming the sensor is the cause.

How does a Tyre Pressure Monitoring System work?

A Tyre Pressure Monitoring System detects pressure changes and alerts the driver through a dashboard symbol. Direct systems use sensors in the wheels to measure tyre pressure. Indirect systems infer pressure changes from wheel behaviour rather than measuring the air directly. This distinction affects what the system reports: neither type replaces a gauge, and the warning symbol doesn’t necessarily identify the cause of the pressure change.

What should I do if the TPMS light turns on?

Stop somewhere safe and check the vehicle’s display for a wheel-specific reading, if it provides one. Some dashboards show only a general warning symbol. Note whether the light is steady or flashing and which tyre appears affected. This information can help distinguish a pressure issue from a system fault. If the vehicle handles differently, prioritise stopping safely rather than troubleshooting beside moving traffic.

Do I still have to check my tyres manually?

Yes. Check tyre pressure monthly and before long trips, even if the TPMS warning hasn’t appeared. The system alerts you to certain pressure changes, but a manual check gives you a reading to compare. Include a visual inspection of the tread and sidewalls. For example, a cut or bulge needs attention even when the pressure reading appears normal.

Where is the TPMS reset?

The reset control is often beneath the steering wheel, but some vehicles use an instrument-panel menu or a button labelled “Set”. Its position and reset sequence depend on the vehicle. Use the handbook’s index or dashboard illustrations to locate the right control. Avoid pressing unfamiliar buttons while driving, and don’t reset the system until you’ve dealt with any pressure issue.

What happens when I don’t use the proper tyre pressure?

Incorrect pressure can affect how a tyre meets the road and how the vehicle handles. Under-inflation can trigger the TPMS warning; over-inflation may not, because UK systems aren’t required to alert drivers to it. Use the vehicle’s own pressure information rather than a general figure, and follow any different settings shown for the load you’re carrying.

How do you inflate a tyre and reset the TPMS warning light?

Use a suitable inflator and gauge, adding air in short bursts so you can recheck the reading without overshooting the target. Replace the valve cap after checking each tyre. Once the pressures are correct, store them through the vehicle’s TPMS menu or Set control, following the handbook. If the reading falls again or the inflator cannot raise it, treat that as a possible leak rather than a reset problem.

Can you drive with the tyre pressure warning light on, and how far?

There’s no fixed safe distance: the decision depends on the tyre’s condition, pressure loss and the vehicle’s handling. In the UK, drive cautiously only as far as needed to reach a safe stopping place. A flat tyre, visible damage or a change in steering means you should stop safely rather than continue towards your destination. Don’t rely on a mileage estimate to judge whether a tyre can keep going.