• Denjin@feddit.uk
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    22 小时前

    This is the warning for low tyre pressure. Often shows up after you’ve had a tyre change, such as when you go to winter tyres around this time of year.

    • Transient Punk@sh.itjust.works
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      21 小时前

      Colder air also takes up less volume relative to warmer air, therefore exerting less outward pressure. So, if you haven’t aired up since July, it’s entirely possible that the lower temperatures alone can cause this light to come on.

        • anomnom@sh.itjust.works
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          11 小时前

          We get it when we switch over to winter tires and never installed the tpms in the other wheels.

          It’s there all winter, and ignored. If cold air is enough to set off the low pressure warning, your tires were already really low in July. Or you have a leak.

    • tiramichu@sh.itjust.works
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      16 小时前

      Interesting fact, the tyre pressure warning isn’t always measuring your tyre pressure! At least, not directly.

      Some cars have actual pressure sensors inside the wheels which do measure it, while others (like mine) use the ABS sensor - which measures wheel rotations - to determine pressure as a byproduct.

      The theory goes that an under-inflated tyre is smaller in diameter than properly inflated one, and so will have to make more revolutions than a properly inflated one to cover a given distance. By comparing the current status against a programmed normal, a mismatch that indicates possible low pressure can be detected.

      Because what is ‘normal’ can change after you inflate your tyres or change them, cars with this type of indirect sensor will also have a button somewhere to reset it (mine is inside the glove box) so you can redefine what ‘normal’ is and cancel any spurious warning.