this it the coolant level sensor in the expansion tank.
it beeps 3 times right? (sorry you said that)
i bet if you turn the ignition off/on after a few miles its fine.
only on cold days?
few options for you in order id try them:
1 if the coolant level is towards the bottom of the correct range, top it up a bit (not a fix as such but can reduce incidence of beeping)
2 scrape the sensor prongs in the coolant, (they often get a build up of scaling)
3 replace the expansion tank. (as sensor is built in). However there has not been any update to the design and so this doesnt guarantee it wont happend again in 12/24 months time.
the light is on the temperature gauge but is not refering to the temperature but the coolant level if its beeping 3 times.
