How can I adjust the volume of voice prompts?
Once you’ve started navigation with the “Go” button, you can adjust the volume by tapping the “Speech” icon that appears at the top-left of the map on your iPhone or iPad. A mute/unmute option is also available under the More icon (or the Settings icon in CarPlay’s top toolbar). Pressing and holding on the “Speech” icon will also mute/unmute.
The system volume can be adjusted with the device’s volume buttons: first tap the turn instruction at the top of the screen to repeat the last instruction, then use the volume buttons to increase/decrease volume while the instruction is still playing (this ensures the volume adjustment applies to inRoute and not the ringer, alerts or a different audio port).