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Tyre pressure warning light on

Tyre-pressure warning light on? See how to distinguish low pressure, a puncture and a TPMS fault, plus the safest checks to make before continuing.

Prompt attention recommended

Check the tyres promptly

Quick answer

A tyre-pressure monitoring warning usually means one or more tyres may be below the expected pressure, although the system can also need resetting or have a sensor fault. Treat a sudden warning as a reason to inspect the tyres rather than simply clearing the light.

Common causes

  • Slow puncture
  • Normal pressure drop over time or in colder weather
  • Tyre recently changed or pressures adjusted
  • TPMS sensor battery or sensor fault
  • System not reset or recalibrated after tyre work

What should I do first?

Reduce speed if necessary and stop somewhere safe to inspect the tyres. If a tyre is visibly deflated, damaged or losing air quickly, do not continue driving on it. Use the vehicle manufacturer's specified pressures rather than the maximum pressure printed on the tyre sidewall.

Why can cold weather trigger the light?

Tyre pressure falls as temperature drops, so a marginally low tyre may cross the warning threshold on a cold morning. That still means the pressures should be checked accurately when the tyres are cold.

What if all tyre pressures are correct?

The TPMS may need a reset or relearn after inflation or tyre work, depending on the vehicle. Direct systems can also have failed wheel sensors. Follow the handbook rather than repeatedly resetting a warning without checking the tyres.

Will TPMS affect the MOT?

For vehicles subject to the TPMS inspection requirements, a malfunction can lead to an MOT failure. A low-pressure warning caused by an actual tyre problem also needs correcting for road safety regardless of the test.

Useful clues before diagnosis

  • Is any tyre visibly lower than the others?
  • Did the light appear after a temperature drop?
  • Have tyres or wheels recently been changed?
  • Does the warning flash before staying on?

Not sure which warning light you have?

Photograph the dashboard and AutoAid can help identify the symbol, ask follow-up questions and explain likely next steps.

Photograph the warning light

Related AutoAid guides

UK safety references

The Highway Code advises drivers to understand dashboard warnings and not ignore signs that may indicate a serious developing fault. Your vehicle handbook remains the definitive source for the exact symbol and manufacturer-specific procedure.

AutoAid provides AI-assisted guidance only and never a guarantee. All faults, urgency ratings and prices are estimates — a physical inspection by a qualified mechanic may still be required.