What am I doing? Occasionally when I lower the volume with the steering wheel control it jumps from where ever it was 25, 26, 30... right down to 7 as though there is a shortcut to almost mute the volume. Thing is I am not sure what I am doing to set that off, double click, squeeze and hold...
I mught just need to get out the owners manual

 

That's exactly what it is, a third button to mute the volume to a preset(adjustable) level.

 

yup! the thrid button is used to set preset volume. To preset just go to the desired volume and hold down the button. I think you'll hear a beep and voila!

 

There are volume up, volume down, and bottom button is to speak into the system. I believe I am only touching the volume down button not a third button. Is it to double tap or press and hold the volume down button?

 

When your battery gets low in amperage and voltage, I've noticed the car does weird things. One of which is the volume settings. Might be a tell tale your battery is on the way out if you are not using the third button.

Randy B

 

The LS430 has 3 layers of controls on the steering wheel, on mine and most other ls430 I've seen. The top layer is to change tracks and mode of the radio, second layer is to change volume up, down, and preset, and below that the third layers is for the voice commands and phone sync. I have a 2006 ML LS430.
What my interior looks like.