Telephone function with radio off.

[Group Captain]

I have a 2018 C220d. The radio, disc, flash drive all work well and are correctly interrupted by an incoming phone call. However, when these are turned off, the hands free phone does not function. Is it possible to have the hands free phone working and taking inbound calls whilst the radio et al are switched off?

 

[Flyinspanner]

Would think head unit needs power to amplify sound and send to speakers, and to pre amp the microphone.

plus access all the memory to the screen.?

just try it with radio volume on minimal, and see if that suits?

 

[Diesel Benz]

Why would the radio need to be off? Just mute it if you don't like it. Easier to switch audio on if needed. Muting radio does not mute the telephone.