I only know an Android phone and my version of SYNC. Make sure your phone's Bluetooth is on. Turn the volume up on you SYNC...turn the middle knob clockwise...you should see a graph on the screen showing where the volume is from 0 to 25. On the left side of my steering wheel, I press the middle button. SYNC says something like choose a command. I say Bluetooth Audio. The system answers & connects to my phone. On your phone, swipe down from the very top of the screen...like where the clock is, etc. You should see a slider for sound and a drop-down arrow on the right. Touch the drop down arrow and make sure the Media slider is all the way to the right (full volume). Call voicemail and see if you hear anything or play something on your phone...music, etc.