When the airfloe meter goes on my bmw does any

when the airflow meter goes on my bmw does any light come on the dashboard to signal the problem or it just wont give enough power output like mine is doing, coz on the motorway it wont go over 60m/hr when on an going uphill and then it goes on level road up to 90. sometimes it feels as if its cutting out on fuel or some plugs atre not firing well but i recently had it fully serviced.