2004 Mercedes C-Class Owner's Manual - Page 176

Controls in detail Audio system Button and soft key operation In these instructions, the alpha-numeric keypad (right side of radio panel) and the function buttons (left side of radio panel) are referred to as "buttons". The four keys below the display panel are referred to as "soft keys". Operation Switching on/off Switching on: Turn SmartKey in starter switch to position 1 or 2 . or Turn control knob a. Adjusting the volume Turn control knob a. The volume will increase or decrease depending on the direction turned. i The volume setting can be selected separately for the telephone*, audio system and voice control system*. Adjusting audio functions Press the AUD key to call up the bass, treble, balance and fader functions in the various operating modes. Settings for bass and treble are stored separately for the AM and FM frequency bands, satellite radio (SAT) mode, cassette mode and CD mode. ! Do not press directly on the display face. Otherwise, the display will be damaged. i If the radio is switched on without the SmartKey in the starter switch, it will automatically switch off again after approx. 30 minutes. Switching off: Remove SmartKey from starter switch. or Turn control knob a. 176