Why doesn't bluetooth audio work with my car stereo?

[Cristian M]

I have Samsung Galaxy A3 (2017) (model SM-A320F) phone with Android 7.0. The problem is that after successfully pairing (Bluetooth) with my car stereo (Sony DSX-A400BT), when I receive a call, I cannot hear any audio, neither the caller.

In the call menu, the Bluetooth icon is selected. It works if I press twice the icon, to deselect BT and select it again. My previous phone, did not have any problems. Also, if I use a Bluetooth headset (Samsung Mono Headset HM1100), it works fine.

I've tried the app Mono BT router, but it keeps the stereo always on BT audio and I want to listen to the radio and let the phone automatically switch to BT audio only when a receiving a phone call. I've tried SoundAbout app, but it does not work.

Is there a solution to get BT working correctly?

 

[Rukbat]

BT is probably working properly on the phone, especially if BTMono is working (it's a nice app - I've used it for years, especially back when not all apps could "talk" through Bluetooth), but the car audio probably isn't working properly with the phone. (I just use an online radio app, so the phone is always connected to the audio system - I hear a radio program, if a call comes in that gets muted and I hear the call and if I'm using Maps while listening to the radio app, the radio gets muted when Maps gives me a turning direction.)

Bluetooth is a way to get sound from point A to point B, but not all Bluetooth devices work with each other seamlessly. There can be little differences between them, or maybe your audio system just automatically switch on an incoming call and you have to press a button on the audio system (mine would work that way if I were listening to live radio - radio and Bluetooth are different modes on the audio system, but pressing the Phone button switches the audio system to the phone in phone-only mode [no music or radio in that mode]).

 

[Cristian M]

BT is probably working properly on the phone, especially if BTMono is working (it's a nice app - I've used it for years, especially back when not all apps could "talk" through Bluetooth), but the car audio probably isn't working properly with the phone. (I just use an online radio app, so the phone is always connected to the audio system - I hear a radio program, if a call comes in that gets muted and I hear the call and if I'm using Maps while listening to the radio app, the radio gets muted when Maps gives me a turning direction.)

Bluetooth is a way to get sound from point A to point B, but not all Bluetooth devices work with each other seamlessly. There can be little differences between them, or maybe your audio system just automatically switch on an incoming call and you have to press a button on the audio system (mine would work that way if I were listening to live radio - radio and Bluetooth are different modes on the audio system, but pressing the Phone button switches the audio system to the phone in phone-only mode [no music or radio in that mode]).

I understand, but listening to online radio is not an option for me.

The car audio system automatically switches from radio to BT phone on incoming/outgoing calls, but I cannot hear the caller's voice and he cannot hear my voice. However, the BT icon on the call options page in the phone appears selected, but the only way to get it working is to deselect and select it again.

Is there anything that can be done to resolve this problem? An Android update, maybe? Currently, there are no firmware updates available for the car stereo.

Is there an app which can do this for me - automatically switch from car radio to BT phone on incoming/outgoing calls and switch back after the call ended?