Since updating to iOS 15.3, my car won't stay connected; bluetooth keeps connecting and disconnecting

Solved!!!! iOS 15.4 today in my iPhone 13 pro finally solved this f*** issue!!. I tested by doing a phone call after a 1 or 2 minutes of getting into the car and placed a phone call from the car interface for calls (no CarPlay) and the phone never disconnected from my car BT, the call lasted about 16 minutes and no hiccups at all!.

Finally!!

What a relief, after having spent 3 hours across 2 Sunday mornings at the beginning of this month on calls with Apple Support. We tested for triggers for the Bluetooth to disconnect from our 10 year old BMW Mini Countryman media system with a built in Move Sat Nav, biggest purchasing mistake ever, totally useless device!

We had the same issues you guys had been suffering, but this was only on my wife's Gen 2 iPhone SE, my original iPhone X worked when connected to the Mini without issue.

On the SE if you received a call it might stay connected for the duration of the call or appear to drop the BT on the car. If the caller ended the call that could cause the connection to drop also.

We both run the CamerAlert app on our phones and these connect like an incoming call to the Mini. One alert from that caused the BT to disconnect on the car, every time... Not that Apple were interested in that clear relationship.

Anyway 15.4 installed on the SE this morning and BT settings deleted on phone and car, re paired the devices and after repeated use of all the triggers that would cause previous fails it works!

Thank you Gordon at Apple Ireland for your patience and listening to me!

Upgraded to 15.4 last week, unlearned my car connection and re-paired it. All works beautifully again in my 2015 X1 with my iPhone 12. Thanks all for bearing with us and thanks Apple Support for fixing this!

iOS 15.4 is now released and after I installed it 2-days ago, all previous Bluetooth problems with connecting to my 2012 BMW are now resolved and they connect perfectly, just as they did pre-iOS Version 15.3.1.

I am unsure if it was necessary, but I also deleted my iPhone from my car and then I deleted my car from my iPhone, and then I reconnected them from scratch. All is working great now for me and good luck!

I had a 2010 Chrysler Uconnect and had the same issue after 15.3.1. 15.4.1 + forget and delete then re-pair fixed it for me as well. Thanks for the ones ahead that took one for the team to try this upgrade. To bad apple did not point out this fix, maybe too nervous to admit

Also before I Called Att asurion tech support and they did not know of this issue nor had the correct fix. So will circle back to them

Updated to iOS 15.4 and the problems are solved. Phone automatically connects and calls aren’t interrupted anymore. Also when ending the call bluetooth stays connected. #happy

I have a 2013 BMW. Updated to 15.4 and it fixed it AFTER forgetting the BMW on my phone and deleting the phone on the BMW and then repairing. Please try that, if you haven't.

it seems like the BLE on the phone side is experiencing issues transitioning from a low power state.

Perform a network reset and toggle Bluetooth on/off when you need it to connect. It’s a lame work around but should work in most cases until they resolve the issue.

[Edited by Moderator]

I was having the same issue in my Dodge Challenger, so I did some research and I did a hard reset and it fixed it! I have an iPhone 8 Plus and it said to push the volume up button once then the volume down button once then hold the other side button down until the apple logo appears. I hope this works for everyone!

Just to confirm, are you on iOS 15.4?.

for me I didn’t have to reset network settings on my iPhone nor unpair-pair again with my car or anything at all.

installed iOS 15.4 while on the office and in the afternoon when I got in my car, tested it without doing anything new or specific and it worked transparently as in iOS 15.1 or 15.2.

15.4 fixed the issue in my car. The only problem I'm having now is the Bluetooth keeps connecting to my wireless headphones even when they're plugged in and charging which they never did before. They're technically not even really supposed to be turned on when charging. But, just thrilled and fix the issues with my car.

deactiv phone contacts sync from iPhone bluetooth

Magically fixed for me with simply the 15.4 upgrade also. Nice to be back to baseline functionality.

Updated to iOS 15.4 and my Bluetooth connects automatically to the phone and is working without any issues! At last!