I’m experiencing the same issue on my brand new iPhone 15 Pro with 2 different vehicles, a 2011 BMW 528i and a 2011 BMW 335i. Both have iDrive navigation and factory bluetooth. Placing a call from car via the built-in interface (Telephone -> Phone Book, for example) results in one of 3 things happening. iOS 17.2.1.
Call is placed and connects, car shows an active call. After about 40 seconds the car looses connection from the iPhone, while the iPhone still shows as connected and sending audio to the BMW’s Bluetooth.
Call is placed and connects, car still shows as “dialing”. Completing the call using the end button in the interface has no effect. Ending the call on the iPhone does not update the car - still shows as an active call. After about 30 seconds the call ends on the car side, but the connection is lost on the car end - shows that the iPhone is connected but prompts to re-pair. The iPhone always shows as being connected.
Or: call is never placed, the car immediately disconnects from the iPhone while the iPhone shows as the car is connected.
The BMW Bluetooth module has been factory reset via the original BMW diagnostic software, and is running the latest software available from BMW.
Turning Bluetooth off and on (both car side and iPhone side) temporarily restores basic connection between the two devices.
This persists even after setting the device up as brand new, without signing into iCloud or restoring from a backup.
Has anyone received any communication from Apple? I’m going to the Genius Bar tomorrow, but if it’s not a hardware issue then I’ll assume it’s absolutely awful software from Apple. Which is deeply, truly disappointing. Thankfully I still have my 14 Pro (which works fine). This was meant to be part of a “free” upgrade on my carrier, but is proving to be a real pain.