500 SL Discomfort in lower back

[McDonald]

The lumbar support in my car is controlled by a disc numbered 1-5 on the leading edge of the seat base. I don't feel any difference through the range. It seems likely that the mechanism isn't working.

Is this a common issue?

 

[flowrider]

Dont think it's a common issue, mine definitely feels different throughout the range. I find anything above 2 is too hard in the back.

I think the lumber support is air filled so check for any loose air lines under the seat.

 

[00slk]

Our old SL didn't work either, but as said above check connections under seat.