aeb28

The roof was working without issue this morning. Went to close it, stopped half way. Tried to open it back all of the way to move the car, the roof went into the trunk but the truck lid stayed straight upright. I was able to lightly push on the truck lid while pressing open to get it down enough to be able to see behind me and move the car, now it will not move at all.

The current condition is top down, truck lid 2" from closed. No warning lights. No mercedes codes on the vari roof and bar DTC. Trunk lid feels locked in place with hydraulic pressure, no up or down. I can hear the hydraulic pump running when I push the button in either direction.

I have tried pushing/pulling lightly on the lid while trying to move it. I have tried putting pressure on the flaps or "wings" to make sure the switch is engauged. I have tried resetting the window limits. Still no luck.

May be coincidental, consumer battery was changed last week. Top worked totally fine yesterday and this morning so it has been used successfully prior to this.

bav12

Sounds like it's low on fluid. Open the trunk with the little key, see if the top will tilt up by the red button, if not assist it. check/add fluid.
If you want to get it to a closed state and start there then open the trunk and there are two round plastic trim pieces, one on each side of the trunk in the carpet. pop those out and you
will have access to a 5mm allen bolt. They turn the cam mechanism that lowers the front of the trunk. you usually have to turn them at the same time if they still have fluid in them. once that is done you can
close the trunk and try operating from a fully closed starting place.

alk247

Here is the step-by-step manual roof closing instructions.

bobterry99

The trunk lid is attached to the "tubular frame". Whenever the pump is running there should unconditionally be pressure on the frame to either open or close it, and therefore yours should move. Since it won't, then I suppose you are low on oil or the "main valve" in the roof control valve block is not opening for some reason.

amxc320wagon

sorry double post

amxc320wagon

open it back up enough for u to c the lock nut,,, in the center of the seats just but inside the top cover..you can test to c if the tool fits.
turn your key on but do not start,,, hold down the close button,,, turn the key off...it should close,,,,now use your mercedes tool to lock it.

aeb28

Thank you I appreciate the info, I will try that this afternoon. Now that you mention low fluid that makes sense, when I let off the raise/low button it almost sounds like the pump motor "winds down" like it is not under much load... I will start there

I am sure I can also look it up, but what kind of hydraulic oil does it take? I have about a gallon of fresh CHF-11S on hand from replacing the ABC pump but not sure if that will work.

aeb28

Edit: Filled fluid resivoir, when I went to close the top fluid was gushing out of the front passenger side of roof.

Frederick NL

Well, you found the culprit. Front lock cilinder.