Well you got me thinking. I have an 09 as well, so I went out to the garage and checked to see if mine did it. Nope, it doesn't. Do you have ABS brakes? That may be the difference. If not, then have you had any downloads to your ECU lately by the dealer or other? I am a truck mechanic and all our equipment does that when you switch on the ignition. On the trucks it is just a pre-start self diagnostic check. I imagine it's the same on yours although I don't know why mine doesn't do it....unless it's because I don't have ABS.