Previewed at WWDC, launching in the fall.
iOS 8 Causing Widespread Bluetooth Connectivity Issues in Cars
It appears that after upgrading to iOS 8 or purchasing a new iPhone 6 or 6 Plus, users have trouble pairing their phones to their car audio systems. The devices are seeing several different issues, refusing to pair entirely, neglecting to play audio over the speakers, or disconnecting when a call comes in.
Now when I am connected via bluetooth, I place a call, and it says it's going over bluetooth, but it doesn't interrupt my car's music, and the audio doesn't play over the speakers. The only way I can talk to the person is if I press the Audio button on the phone and select speakerphone or iPhone as if it wasn't connected to the car.An ongoing thread on the MacRumors forums suggests that a wide range of different automobiles are having Bluetooth connectivity issues with devices running iOS 8 and iOS 8.0.2, including Hyundai, BMW, Mercedes, Lexus, Toyota, Ford, and more.
The Bluetooth pairing problems are not limited to automobiles, as iOS 8 users have also reported issues pairing with headphones, speakers, headsets, and more.
According to one iPhone 6 owner experiencing issues, Apple support is aware of a compatibility issue between the Bluetooth "used on the iPhone 6 and some car/navigation Bluetooth." Apple is said to be working on a fix for the issue, but in the meantime, some users have had temporary luck logging out of iCloud, forgetting connected Bluetooth devices, using the "Reset All Settings" and/or "Reset Network Settings" option on their iPhones and restarting, re-pairing their devices with their Bluetooth devices, and then logging back in to iCloud.
Attempting to use "Reset All Settings" should be done with caution, however, as some users have noticed that all of their iCloud Drive documents have gone missing after using the feature.
iOS 8 has not been Apple's most stable release. The operating system has seen several issues, including a major HealthKit bug that caused the company to pull all HealthKit-enabled apps just ahead of the public release of iOS 8 and a significant issue with the iOS 8.0.1 update, which disabled the cellular connection and Touch ID of many iPhone 6 and 6 Plus users.
iOS 8.0.2, released last week, fixed several major issues including the HealthKit bug, and Apple has plans to release another update in the near future, having already seeded iOS 8.1 to developers.
Update: According to some users who have installed iOS 8.1, the new update fixes the problems with Bluetooth.