If Bluetooth disconnects, the call in the vehicle may transfer back to the phone in the following situations:
• If your engine is off, your vehicle may time out of accessory mode to save the battery
• If your wireless signal is not strong enough. If the problem continues when you’re no longer in accessory mode or when you have a strong signal, you may need to try deleting your phone from the paired devices list on your vehicle touch-screen and then pairing it again