I bought my 2013 Ford Explorer Ltd, certified pre-owned, 2 months ago. The first few times I went to end a phone call I was able to push the button on the steering wheel that sits over the voice command button. I hit the button and it ended the call. It's the button that looks like a telephone with a downward arrow. Now it's not working. I have to actually go to the screen on the dash to end the call. If I hit the phone with the down arrow button twice it redials my last call. However, I'm more interesed in why it won't work. I'm sorry for such a dumb question but there isn't anything about it in the manual and I hate having to go to the dealership to ask. Any suggestions as to why I can't end a call with the button with the phone and downward arrow?