abs and e brake light comming on

Hi, just wondering if anyone was having the same problem as me, in the last 2 weeks my abs and e brake light has come on twice and stayed on as well as the service brake system warning flashing. Does anyone know what could be wrong? Its been like -35 degrees some days in the last bit could it just be too cold?

thats possible. road salt etc... will build up also causing the sensor not to pick up.