Rear view message display?

Hi all! I'm new here, just bought a 2013 yesterday and I couldn't be happier with.

Thanks to this forum I'm figuring things out. But so far there is one thing I can't figure out.

On the inside rear view mirror, there is a button and when I press it, I get the following message on the mirror itself:

No Signal Input1

Where is this coming from?

Thanks all!

I suspect you have an aftermarket mirror that is set up for one or more cameras (video signals). Original equipment backup (or surround view) camera images are displayed on the radio screen. The rear view mirror in the SL has automatic dimming and home link buttons (to control garage door openers, etc.) but it has no place for input signals and no place to display the message you are seeing. The SV and S mirrors have fewer features than the SL.

Gerry

Thank you so much, you are right! I got the Carfax and can tell the mirror was replaced shortly after being leased by the first owner. I was able to find out some more details and it is for cameras.. but unfortunately, I don't think they were left on the vehicle.