Goodwood

I go into Vehicle settings, and attempt to raise my lumbar bag. The icon moves up, but doesn't actually move the lumbar bag in the seat. What am I doing wrong? Tried it with car running and even not running.

rmorin49

It's likely that the lumbar support has a leak. I've read other threads where this has been the issue. Do you hear the pump run and any noise that sounds like air leaking?

Goodwood

Not hearing anything, although I really wasn't listening for it. What other things operate on this same pump? I will check to see if the pass side is also malfunctioning.

crconsulting

If you're not hearing any noise from the air circuit, it's possibly electrical. There is also a module for each seat: 2219005404
I don't know if you have active seats but the lumbar (and seat bolster) assembly looks like this.
Make sure to check all your fuses, air tubes and electrical connectors to the module, just in case....
XENTRY probably has logged an error code if its electrical.

jrupp

Is this a DIY project? I bought my SL550 about a year and a half ago with only 5,900 miles. Everything is great except the seat bolsters don't work. No noise, no hissing, etc., so I'm assuming it could be electrical. Can live without the feature but am willing to try and fix it if it's not too tough.

crconsulting

Is it BOTH sides? If it’s just one side it’s fairly easy to access/remove the back panel on the seat. Diagnostics is always the challenging part. You never know, it may be something physically obvious.

this may help

https://mbworld.org/forums/sl-class-...t-inflate.html

Goodwood

So, determined that both sides' lumbar adjustments aren't working. Funny, the side bolsters and massage work on both. Unlike some cars the lumbar has a fixed amt of firmness, but just goes up or down. I cannot detect any movement. Could it be a fuse? Going into the shop in 2wks for a few things, and will have them address the problem if it isn't a big deal. Actually, I think I want to keep it in its lowest position, but won't know until I can sample the other heights. Thoughts?

griza

Just curious and my apologies if I missed it in another post. Did you get a PPI on the car? A shame you are having these small but annoying issues.

Goodwood

No PPI, but car was thoroughly gone over to qualify for CPO. The list of replacement parts was pretty long, but obviously they overlooked the lumber adjustments. If my Indy shop can't fix it easily, such as a fuse, then I will have to live with it until it needs other warranty work at the stealer. It's odd that all the other seat functions work, but not the lumber. btw, it's going in to have the Renntech sport muffler installed Mar 6. From what I can tell, the Renntech only increases the sound a little, which is what I want, and is the least likely exhaust part to cause a potential denial of warranty, and is easily reversible, since it's just axle back. Just came off a loud P-car with aftermarket exhaust, and an even louder Mustang GT. I've grown out of that phase with the acquisition of my SL550. Removing mufflers, cats, and or resonators, isn't even a consideration. Wish I would've done a little more research, because the AMG version has the switchable muffler flaps. I think another 15-20% loudness will be perfect.

crconsulting

I had assumed that was done already.
definitely check fuses first…..
40,43,116,126

see attachment: It’s for an sl450, but seat fuse location should be the same

Goodwood

Update: Turns out the problem was user error! As a desperate last try to get the lumbar working again before taking it into the dealer, I played around with the settings once more, only to discover the up/down/left/right functions of the big wheel. Turns out the lumbar works fine. Talk about egg on my face! Mind you, this is my first MB, so not at all familiar with the big wheel. Thanks to all for your input.

rfb3

My new to me 2018 SL550 has the same issue, but it's not the wheel... I'll try to report back what I find but I am in no hurry at this point. I just got the car 24 hrs ago...