Yesterday I got a message engine coolant too low when accelerating away from a roundabout, first time its happened, the message then returned each time I accelerated up to 2500 rpm from the junction or roundabout, after 15 secs the message always disappeared.

Today the message came on at start up and just stayed on all the time I drove the car, I checked the coolant tank and their was coolant right to the top of the tank.

I am concerned it may be the water pump but I do not know what to check

any suggestions please

thanks Richard