Mercedes seat help

[CAH706]

Hi,

I have a 2013 350 AMG Merc cabriolet at the moment as a loner following someone rear ending me.

The seats are electric and I can figure out how to work those ok but the 4 lumbar (?) buttons by the side of the seats don't seem to do anything.

Is it likely they are bust, inactive or am do I need to do something else to get them working? Manual has no reference to them am all.

Cheers