*Bug report* No Audio on iPhone after unplugged from car, and "Only one accessory can be used at a time" error after iOS 14.x update
Since one of the iOS 14 updates, about 6 months ago, after a few uses in the car, iOS will not see that the iPhone has been unplugged from the car, and as a result you will get no audio out of your speakers and attempting to plug the phone back into the car will cause a "Only one accessory can be used at a time" error to pop up on the screen.
Checking your sound output settings will show that the iPhone thinks it's still playing audio out the dock connector, and there is no option to play audio out the speaker. The ear piece will still work, bluetooth or other headphones will still work, however lighting devices won't work. There is also no interface sounds like keyboard clicks, lock sounds, and whatnot when in this state.
Both of these things seem to sometimes happen independently of one another, and sometimes happen on connection or disconnection from a car, but always after one of the two.
The only work-arounds right now are:
- Rebooting your phone
- Pressing and holding the power button, waiting for the shutdown prompt, releasing the power button, then holding the home button until you're prompted for your passcode.
- Some people have mentioned that toggling Settings > Touch/Face ID & Passcode > USB Accessories off/on will also fix it, though I haven't tried myself.
This is very clearly an iOS bug as it happens on all cars, as seen by numerous other posts, and the only common point is that it started about 6 months ago after an iOS update.
Here are some other people having this issue:
https://www.reddit.com/r/CarPlay/comments/lg8g58/carplay_only_one_accessory_can_be_used_at_a_time/
https://discussions.apple.com/thread/251351919
https://www.reddit.com/r/applehelp/comments/malw60/only_one_accessory_can_be_used_at_a_time_error/
It's very clearly a bug, and there have been several iOS updates since that have failed to address the issue. Perhaps it's more common on older phones, however it is not related to the phone hardware, or phone data, as I've had both my hardware replaced and this happens with a fresh or restored iPhone, using multiple authentic Apple cables.
Can someone at Apple please escalate this to an engineering team?
