astouffer

Just started having a problem with my 2007 E550. The rear end is fully raised and will not lower. Not many forum posts about this problem. I checked the wiring at the compressor and valve block and it appears fine. According pretty detailed info at https://w220.ee/Airmatic#Vehicle_Level_Too_High it sounds like rear level sensor is bad. Thoughts anyone?

bbirdwell

Put a scan tool on it and you'll know if it is the level sensor in under 5 minutes. Or the valve block. Or both rear air springs internal valves failed. Or if the electrical lines to the rear air springs were damaged. Or the Airmatic Control Module has a fault. See the pattern here? Scan it and read the codes. DAS/Star/Xentry is the cat's meow as it will narrow the problem down to one of fifty or so possible causes but an iCarSoft scanner that reads MB codes should give the basic info.

VII

It can be a stuck valve or the sensors, the rear level is not individually controlled both sides are raised are lowered at the same time. If relief valve is stuck then the car can't lower (I don't know if there is an error trigger for car too high for the cluster), if height sensor is malfunctioning the car does not know where to go.
Diagnostic is likely the most cost effective way forward, if unavailable I would start with height sensors.

astouffer

I don't know why the airmatic system is treated as a literal box of magic. There are causes and effects to any system which can be mapped out. In any case thanks for the tip VII, the culprit turned out to be the linkage to the rear height sensor. The original plastic rod snapped off leaving the sensor at one extreme position. I repaired it for now and the rear slowly leveled down to where it should be. There is a new part number for the linkage 2113201889 in case anyone in the future has the same problem.

MACEDON

Car rear lowered while driving, I can raise it with star and it holds, so now I have to tackle what is the cause

What do I do in star to do this? I scanned it but I get no code for the rear sensor.... my car slammed in the rear. But, when I raise the car manually w/ SDS it holds, just the rear level is stuck at 95mm... I have a feeling the sensor is fine (since I did not get a code for it) but the lever on it is freaked...

bbirdwell

You can go into STAR and under actuations raise/lower the rear of the car while simultaneously monitoring the voltage output of the rear sensor. Voltage values should increase/decrease relatively smoothly as you raise/lower the rear of the car. In my setup, it's under control unit ENR, "actuation of level valves". It is possible the level sensor is fine electrically but the sensor actuation arm is broken.