Hi

I raised my ML500 W164 2009 model to the OFF ROAD LEVELS. I turned the knob to drop out of OFF ROAD LEVELS. It sais BUSY LOWERING on the dash screen. It does not drop at all?

I replaced the pump and the valve block.

Any ideas about what the problem could be?

Thanks
Enrico

Have you checked your level sensors? I doubt all are an issue, but if a couple of them are seized/stuck, they won't allow the truck to lower. Check the arms and make sure they can be moved/wiggled by hand at the joints where they mate with the height sensors.

Do you have a scanner capable of pulling airmatic codes?

While considering lowering options for my sprung ML, I thought, hey maybe do generic bags, but without an internal pump or block to deal with. Just a pair of Schrader valves on the bumper someplace, to fill and adjust manually, not relying on a cockpit control.

That is, I wonder if, at a certain point, it's worth abandoning the original system and "hard wiring" new air lines.

Hi

I checked the level sensors. They all good.

Looks like the release valve or something in the valve block is not functioning. Its a new valve block so Im guessing it could be the wires between the valve block and level control knob.

What brand valve block did you use for replacement? Some other members have had new but faulty blocks from non MB manufacturers.

If you suspect wiring, you can check them for continuity to start with. I've not been forced to deal with the valve block yet, so I don't know how easy that wiring test would be.