no, flashing means it is not engaged yet. beeping means you are doing something wrong.
Stop, put tranny in neutral, move selecter to 4lo, wait till the dash light stops flashing. It porbably beeped at you because you either were not in neutral, or started moving while the light was still flashing. See instructions in owners manual for more detail. If it flashes constantly for several minutes, there is a problem. It usually takes a few seconds of flashing before it engages.