I have a 2008 Prius. I use an iphone 6s with iOS 11.2.2 When I get an incoming call the volume is so low that I can not hear it. Same with listening to voice messages. I can quickly grab the phone go to the keypad and hit a button a number of times and the volume increases. But I have to do that each time. Did upgrading to the newer iOS have anything to do with this. Everything had been working just fine for the past 7 or 8 years!
