Changed the Battery!
 

FWIW,


Ok, a week after the SLS mssg showed up the battery collapsed almost completely. I got a new battery and installed it thinking that might be the cause of the problem but no luck.

So I continued the search and checked all the compenents like the relays, compressor and sensors. To no avail, all was well under the vehicle. So, as a last resort I was going to ask the dealer to reset the EHC and drove out last night to drop it off.

To my amazement about halfway to the dealer (10 miles out) I discovered that the warning was gone and the system came back alive. I played a bit with it and then turned back home. This morning all was fine as well.

So, I have to conclude that the battery failure is likely to have been the culprit in this case. Not sure but it is a bit too much of a coincidence I think.

Height switch status only in middle position
 

Hello, my name is Joe and I come from Germany. Excuse my bad English. I have a problem with my air suspension. the SLS regulates only the front axle. The rear axle does not regulate. The switch for the ride height control lights up in the middle position. You can not adjust up or down. Does anyone have advice for me? Thanks in advance

You may have a fault switch, try to replace the switch.

Are you getting a suspension inactive message on the dash?

When you press the switch for up or down what do the lights do? Do they flash or glow steday and if they flash which one is flashing?

Hi, when I press the button nothing happens. only the LED lights up permanently in the middle. No flashing of the LED. on the dash is no message.

Hi Joe!

How old is your battery? I didn't realize until my battery died yesterday that my ride height was lower than usual as I would get that feel of too much bounce in the front like the air springs were bad. Plus, last Saturday I wanted to raise to the highest setting and when pushed the top LED flashed a few times then went solid back to the middle. I thought it odd but, didn't pursue it.

Changed the battery and now it's sits higher than before and the height adjustment works as designed!

May not be the problem for you but, worth a look see?

Thank you for your tip. But the battery is only 2 years old and everything else works perfectly. The funny thing is that the sls works perfectly on the front axle. Rear axle does not move. In memory fault no error code is stored. LED lights on, but be unable to operate.

If you don't have access to a GT1 and can't run the test plans, this might be a good option.

Can you get a hold of a known working switch (used/new)?

Yes, I've ordered a used switch. Let's see if it works then. Maybe it helps me .. :-)

I say, pull out that relay in the trunk for the air susp, and put it back in. See if it resets anything.