2015 4Runner Limited terrible phone audio

On my wife's 2015 4runner limited, the sound quality is terrible when she uses hands free for phone calls. It only plays out of the drivers side dash speaker, when on a call and sounds scratchy and distorted with an echo on both ends. The speakers all sound fine when using blue tooth for pandora, spotify or Amazon music. I have deleted all phones from the head unit and deleted the car from all phones. I have tried iphones, Droids and Google phones with the same results. I have done the Toyota update via the usb drive install, I have disconnected the negative and positive batter cables for 30 minutes to overnight. I have unplugged & replaced the 7.5 DCM fuse under the dash near the drivers door. I have adjusted every audio setting that I can find on both the phone and the head unit. The SOS light cycles upon ignition but doesn't remain green nor red. I get the Toyota reply that I can re-subscribe if I push the SOS button.

Any help is greatly appreciated!

 

It hasn't changed since 2011. The phone audio is terrible.

 

welcome

 

catbrown357 The strange thing is that it hasn't always been like it is now. It used to play through all of her speakers but has recently started only playing through the drivers dash speaker.

 

Can confirm. The mic is absolutely garbage. Unusable.

 

That is interesting. I was referring to the mic having terrible quality and the audio being awful for the person on the other end. Your problem points to something with the head unit/bluetooth interface.

 

Crazy thing is it seems to have something to do with the DCM/battery, but I can't find the DCM battery to test. The head unit works on all other accounts. I literally have traced everything I can logically think. I even replaced the dash speaker with no change in the terrible quality.