2K5E55AMG

Hi all, first post here.

Just bought a 2005 E55 AMG about a year ago and 4 months after I've been having rear suspension problems.

The rear would drop after I start the car and drive out of my driveway. I noticed that when I unlock the doors with my key fob, there is a release of air and after that I switch the engine on and drive out of my driveway, the rear would slowly drop lower and lower. After I drive for a while, shut off the car, then turn it on, I see the rear go up. This happens randomly and often. The rear doesn't drop overnight or even over weeks, only when I either unlock the car or start the car.

I've replaced the rear airbags with Arnotts, replaced the air compressor with Arnotts, replaced the valve block, replaced the control module, replaced the rear level sensor. I've had my indy hook it up to DAS and no codes or anything.

Does anyone have any advice or input?

Thanks in advance!

hayseed

iTrader: (2)

if its consistent every time you start/drive car then maybe the rear ride level sensor is having issues, if its intermittent then I have no idea -- was it having these symptoms before you swapped out the suspension ?

2K5E55AMG

It is not consistent - it happens intermittently. Sometimes after a few days, sometimes after a few weeks.

It was because of these symptoms that I swapped for the new Arnott airbags. I've also swapped out for a new level sensor. Still no good.

Hulk

Run a test in star and it will tell you if the pump is strong enough or if it holds pressure

2K5E55AMG

My indy ran all the tests and said there were no codes or leaks.

I've also put in a new pump.

Hulk

Check your linkage

2K5E55AMG

Can you clarify on the linkage? My indy said he's checked all the connections.

It's weird that it's not consistent. Can it be a pressure issue?

Hulk

The linkage is the part that keeps the height of the car
Search lowering links
Your stock rear linkage might be rusted and broken

2K5E55AMG

Oh that linkage. That linkage was replaced along with a new rear level sensor.

Hulk

Hmmm weird

Hulk

Check the valve block
Spray it down with soapy water

2K5E55AMG

I'm really stuck on the fact that the car releases air when I unlock the car. I've noticed on a few occasions that after I hear the air release, the rear slowly drops. This seems to happen when I don't use my car for period of 2 weeks or so.

It's not slammed all the way to the ground, but it's pretty close to wheel well after it settles down from the drop. No warning message when I leave it on comfort mode, when it's on Sport I and the rear drops, I would get a message.

2K5E55AMG

New valve block was put in.

Max.H

Same happened to me. My car would do the same thing, Checked with star also. I went nuts trying to figure it out. It was the rear air bag. I replaced both and all is fine in the rear. Hulk has a pair of the rears for sale. I got dibs on the fronts.

2K5E55AMG

I've already replaced both rear air bags with the Arnotts.

Thinking it may be something with the central reservoir and pressure.

Max.H

Did you spray soapy water to see if you have any leaks at the fittings around the air springs and all the connections?

2K5E55AMG

My indy did the leak tests and told me there were no leaks in the system.

bbirdwell

-SAS module wakes up when you perform any of the following:
---key activates EIS
---door activated
---trunk lid activated
---parking brake
---stop lamp activated
-If vehicle level is >10mm higher than normal, the vehicle will lower to normal.
-If vehicle level >30mm lower than normal, the vehicle will raise to normal level if reservoir has sufficient pressure.
-If vehicle is >65mm lower than normal, vehicle will raise to critical level (-63mm) if reservoir has low pressure.

Your post #12 would indicate the SAS module is interpreting the sensor input as “vehicle too high” when you unlock the doors. It won’t hurt to calibrate the rear suspension. Not difficult to do so long as you have the proper diagnostic system. Remember that the rear sensor voltage needs to be between 2.2 and 3.0 volts and the rear axle angle should be between -1.5 and -0.9 degrees (the more negative the axle angle, the lower the car and greater the negative camber and greater the voltage). You’ll need Chassis control unit ENR and “Initial startup with manual settings input for new control unit / level calibration”. I posted on the technique in the STAR diagnostics How-to DIY thread under “W211 suspension calibration”. Not difficult to do.

2K5E55AMG

My indy recalibrated everything when he swapped out for a new control module.

When I unlock the doors, the rear is still at proper height (even after the air release) so the SAS would think that the height is fine. After driving about 20 feet, I would see the rear slowly drop. I would drive it for a 5-10 mins, shut off the car, and turn it on, and the rear would rise (sometimes it would take multiple tries this to happen). During that second start, the SAS module probably recognizes that the car is too low and add air. Also, if I drive longer than 5-10 mins with the rear dropped, after a while it would rise up automatically.

bbirdwell

2KE55AMG, PM me your email address.

2K5E55AMG

Sent.

Hulk

It could be anything at this point. The lines, the connectors, even the module. I went through this and I changed all 4 sides and then again after a while something else
I went coilovers end of story

SuperChargerE55

Just to check been there tried it only other way around mine was to high. Recalibration did noting but reset and recalibration. My pump was tired fixed that first is why I ask since u don't mention it but I still add it (fixed mine replaced piston rings cheap fix)
Anyway maybe this info can help u or others.

Error coming on into a journey is typical of a tired compressor, as when the car drives over 30MPH the compressor starts to top up a storage tank, this is the biggest test for the compressor, if it cannot fill the tank up to a high pressure it will throw the error light on, but stop and switch the car off and on it will clear and be ok until 10 mins later after the car starts driving.

If the car sinks down when parked overnight this is a leak, if the car is slow to lift this is a weak compressor,
Symptoms:
Noisy Compressor. Air suspension rising slowly or not raising at all. EAS faults. Suspension faults on OBD display. Pressure increasing slowly errors. Still suspension or stuck at one height.

Fault codes:
C1A20, 5503, 5505, 5508, 1400,1772,1769,1400,1772,1577.

Stuck at level. Over temp. Suspension Failure. Level Error
----------------------------------------------------
Level sensor error codes:
5150, B22/3 (Rear axle level sensor): Failure of both signals

Hulk

Good point however he has no codes
It gets difficult at that point

2K5E55AMG

I've replaced the old pump with a new Arnott pump.

The car doesn't sink overnight, it actually stays up for weeks if not used. And the car lifts ok when I hit the raise button.

Let me know what you think of this: I think it may be an issue with the storage tank maintaining the proper pressure or air. I believe the tank is used to fill the airbags when the engine is not on. After the car is sitting for a long period of time, the air in the tank is not sufficient to supply air to the rear bags so during the door unlock (engine off) the rear slowly sags. So the first 10-15 mins of driving results in sagging rear. But after driving for 15-20 mins, the compressor refills the air in tank and rear bags and thus inflates.

I have never gotten the error light for not enough pressure from compressor to tank so I'm not sure if there's an issue with the tank. My indy has hooked up to STAR and got no codes.