The radio does not indicate voicemail status. For most phone carriers, voice mail can be accessed by dialing the phone number for the mobile phone that you are using.
If a dial tone passcode is required to access voice mail, press the Voice Recognition switch during the call. Speak the passcode numbers and other special characters as needed. For example, to enter a passcode as "1234#", speak ONE-TWO-THREE-FOUR-POUND into the microphone.