Airmatic suspension s211 2005

[Bigasho]

Afternoon all
I have a s211 2005 E320 the suspension is running low about 64 cm from the ground to the wheel arch, my icarsoft code reader said that the axle level sensor was at fault, there is only 1, I ordered a Chinese special, I fitted it and the car ran lower, I then took it to a Mercedes specialist who put it on Star and the only fault the system found on the suspension was a faulty relay , the relay was changed but still ran low , I have now put the old Mercedes sensor back on and my scanner showed 0 mm and the car again sat at 64cm , after opening the tail gate I along with my uncle and my 50kg dog sat on the back and you could feel the car raising the car then sat at 68cm ,the top of the tyre could now be seen, we got out it and it settled down to 64cm, I then drove 50miles home and it road at 58cm and I had to careful of any bumps in the road .
Please is there anybody out there who can give me any idea what I can look at next, many thanks in advance .
Peter

 

[E55BOF]

I'd try fitting a new genuine Mercedes level sensor and see what happens.

 

[Bigasho]

I'd try fitting a new genuine Mercedes level sensor and see what happens.

Thanks for that but I have put the old one back on as it looks like it was the relay that was the problem according to the star system.

 

[E55BOF]

Firstly, I don't think you have Airmatic; I think you have a much simpler pneumatic self-levelling system on the rear only, and coil springs only on the front. Is that correct?

Secondly, where was the STAR check done? It indicated a different fault cause to the iCarsoft; you replaced the relay, but the fault was still there. Unless the replacement relay was also faulty, the STAR diagnosis was demonstrably wrong. In view of that fact, why do you conclude that the iCarsoft was wrong too?

Unless you want to take the car to a competent indie and get them to fix it, the next cheapest component after the relay to replace is the levelling sensor.

 

[Bigasho]

Firstly, I don't think you have Airmatic; I think you have a much simpler pneumatic self-levelling system on the rear only, and coil springs only on the front. Is that correct?

Secondly, where was the STAR check done? It indicated a different fault cause to the iCarsoft; you replaced the relay, but the fault was still there. Unless the replacement relay was also faulty, the STAR diagnosis was demonstrably wrong. In view of that fact, why do you conclude that the iCarsoft was wrong too?

Unless you want to take the car to a competent indie and get them to fix it, the next cheapest component after the relay to replace is the levelling sensor.

The car was on the STAR diagnostic system at a Mercedes specialist, at that time I had changed the level sensor, the only fault he found was a faulty relay which I have changed ,I can only assume the level sensor was working correctly,.

 

[zipdip]

Look all the rear height sensor is a potentiometer,and they do go wrong,more often there is a crack in the plastic,look on ebay for one that fits your car and change it again.the way these get broke is going over speed humps to quick,

 

[Bigasho]

Look all the rear height sensor is a potentiometer,and they do go wrong,more often there is a crack in the plastic,look on ebay for one that fits your car and change it again.the way these get broke is going over speed humps to quick,

Thanks for your reply, the potentionmeter is that a posh word for the level sensor, if it is i have put 2 on and the car will still not ride at a set height it will go from 0mm run height down to -70mm. I can park the car and it will go down within an hour other time it will stay up not at the correct height for a day or so.

 

[E55BOF]

Thanks for your reply, the potentionmeter is that a posh word for the level sensor, if it is i have put 2 on and the car will still not ride at a set height it will go from 0mm run height down to -70mm. I can park the car and it will go down within an hour other time it will stay up not at the correct height for a day or so.

Potentiometer is the electronic part of the level sensor; it generates the signal that tells the system to change the rear ride height.

If the car never rises to the correct height, either the level sensor, the compressor or the ECU is faulty, or there is a leak. If it sometimes does and sometimes does not, and goes down when parked, which I think are the symptoms you are describing, you very probably have a leak.

 

[Bigasho]

Thanks for your reply, so the Potentionmeter is an integral part of the axle level sensor or is it separate to the sensor, if it is separate would you have any idea where it is located. Cheers

 

[BlackC55]

It may need calibrating on a Star.

 

[E55BOF]

The potentiometer is the sensor, really; take that out and all you have left is the casing and the actuating arm.

OP, if I were you I'd look for a good indie near you and find out exactly what the problem is.

 

[Bigasho]

Thanks for your reply ,the suspension does seem to have a mind of its own , I have just been out in the car , I have been in my house for 5 minutes, I have just walked out to the car looked at the wheel thinking that looks high and close to the ride height opened the front passenger door and the car went down

 

[E55BOF]

Find a good indie and see what they say. STAR can only go so far with pneumatics; it can't diagnose or find leaks or other non-electrical problems.

 

[Bigasho]

Thanks for that ,it was on the STAR system last week the fault that he found on the suspension was a faulty relay which I have changed ,thanks for confirming that the STAR will not detect leaks. Today I am going to look at the compressor .

 

[E55BOF]

The compressor either works or it doesn't; it's unlikely to be producing enough output to pressurise the system intermittently, and I doubt it will be the problem. The relay wasn't the problem either, or replacing it would have sorted it out. I'm pretty sure you have a leak.

 

[Bigasho]

Well the bags have been changed along with the compressor, it's holding it's height but it sits around 65cm from the ground to the wheel arch , the mechanic who done the job tried to set the height he has not got the STAR System but he able to raise each rear corner independently the voltage shows 1.9 volts while adjusting the system the voltage goes up to and over 2.2 v while raising the suspension, he set the correct height, he disconnects the system and the level goes back down to 65cm ,he even put 25 ltr drums in the back and set about adjusting the height again and again when he disconnected the system it dropped back down to 65cm. Any ideas would be welcome.

 

[Jobsworth]

Olly mentioned it earlier. With a proper Star machine you can adjust the “Romess” calibrated height setting. The car will then maintain that level whether it’s empty or fully laden. It sounds like yours need recalibration

 

[jamesfuller]

Can you post some photos?

I can't be the only one that wants to see the 50kg pup