So I have a 2003 W220, S500. It has new rear struts, the front ones have been replaced twice, new compressor (2 years old, but brand new at the time), and valve block was checked. All the sensors seemed to have been checked, as they seem fine. One day while parked out in slightly colder weather roughly 40 F, I started it and it showed an error with the airmatic system, and said visit workshop. It did NOT say vehicle low or anything else. I looked around, and the car sat roughly 3/4 of the highest ride height possible. Drove it home, left it overnight and it did not lower, but stayed at the same level. Two days later, while not touching it, turned it on, and no codes. I lifted it up with the button on the dash, and it raised and lowered like usual. I could hear the compressor working as well. The next day, I drove it, and after 10 minutes, the error came up again. I read the code, and it was "C1517-128, Suspension Strut is implausible". I took it to my mechanic, he read the codes, and nothing showed up. They ran a full test on the system and compressor, 25 minutes long, and it was 100%.I came to pick up the car, started it and the code came up again, C1517-128, and he ran it as well. He went through his diagnostic servers, and it showed that the issue was resolved with a new compressor or new airmatic struts. Now the issue I am at, is what could it possible be? My thought is a possible relay, as he said that all the ride height sensors seem to be good. Another thought I have is the pressure sensor on the airmatic system, either on the compressor or else where. Another note is that, the car won't raise itself with the compressor once the message is displayed (visit workshop), but it does not lower nor does it sit through at all. It just stays at the same height. Any thoughts or has anyone dealt with this before? I am really not about to replace the compressor or any strut again since it obliviously sits at specified height and without the error, the compressor turns on and pumps the struts perfectly.Any ideas are much appreciated.

 

My first guess is an intermittently faulty connection at one of the front wheel wells. It is notoriously difficult to get those connections in perfectly. There are two harnesses from each side of the front suspension that go thru at the front of each wheel well. It helps a lot if you hold the plugs together while removing and inserting.
I would not spend a lot of time worrying about this - it doesn't sound as if this is a problem that would ever strand you, especially since it seems to be self-healing. I probably would try removing and inserting the plugs on both sides, though.

 

Thanks Wally,
So my mechanic replaced the relay that he thought might have been causing the issue, but the error message still came up. Regarding the connections you're talking about, could you explain a bit more specifically were the two harnesses are on each side of the front suspension? Are they able to been seen from the wheel well, without taking the wheel off, or is it better to go from the bottom of the car?
Thanks.

 

 

Easier to access the plugs with the wheel off, but you probably could get to them by turning the steering all the way.

Were these replacement struts MB-rebuilt, Arnott-rebuilt, Arnott new manufacture, or used?

 

They are new Arnott struts. I took the wheel of and the connections seemed to be in the wheel well very securely. Did not feel like using more force to pry them off and risk breaking them. I suspect that they are dirty and just need a clean. My mechanic is going to take a look at it in a few days while he has it up changing something else unrelated to this issue.

 

Hey Bamberger_1
So the codes my mechanic read without the error all lead to the compressor as well, but they tested the compressor and it performed as needed. One assumption, if it isn't a bad connection at the front wheel wells is a pressure loss in the valve block or around the compressor, possibly were the pressure is diverted to each strut, but I am hesitant on that.

 

I suggest you purchase a 10 ml vial of "STABILANT-22" and have your mechanic take each connection apart and using the tiny applicator, put Stabilant-22 on each pin of each connector. in the system.Faulty intermittent electrical connections are all but impossible to find or fix by any other method. This stuff is fantastic. The 10 ml vial is about $75, but it is a lifetime supply===and the biggest 'secret' of auto electrical shops.

 

I agree that Stabilant-22 is great stuff. Hitting a connector with DeoxIt D5, then a light application of Stabilant-22 should take care of poor connections. Corrosion Block is another good product that is a little more specialized to take care of general salt corrosion problems.

 

Did you ever figure out the problem?