Run flat tyre warning light is on i have checked tyre pressure

This will only come on when a tyre has dropped in pressure (not spare). It work on the principle that a tyre with less air has a smaller rolling circumference and therefore a different wheel speed. This is then monitored against other signals from other wheels and determined that a loss in pressure has occured.

If all tyre pressures seem ok, there could be a chance of a small unoticeable leak and would require a bath test. This is when the tyre is dipped in water and bubbles would appear where the puncture is.

Ultimately the system may just need to be reset, or has incorrectly been reset from a tyre change. For this you just press and hold the TPC button (located on the centre console above the gearstick - looks like a flat tyre with an exclamation) turn on the ignition to position 2 and the light will come on re then yellow,go out, come back on yellow. When it comes back on yellow it re-initializing the system. You can let go of the button and after 20 odd seconds the light will go out for the final time, completing the reset.

If the light continues to come on after the reset then you definitely have a puncture somewhere!

Hope this helps!

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