R230 SL Suspension issues

[BaldGuy]

My SL has a strange fault, when I got it, the Brabus suspension module was messing around so that was replaced with a Renntech one.
I've lowered it sensibly at 1" for now and it rides lovely, however when you park up, the drivers side rises back up to factory height..... This is only the drivers side... If you start it again and raise the suspension on the button then lower, it will stay low whilst parked...

It's been recalibrated and checked for faults on Star and all clear, the pump is fine also... Could this be a height level sensor problem on the drivers side? Although why wouldnt it raise whilst driving?

Not interested in "why have you lowered it" comments or other pathetic comments from the usual idiots...

All genuine help grateful....

 

[SavMan]

Can you actually see it raising or is it while parked overnight?
Whats the drivers rear doing have you compared it with the passenger rear?

 

[BaldGuy]

Hi Paul.....Yes when you park up it's at the lowered height... As soon as you turn off and get out you can see it raise up to the normal height both front and back on the drivers side. The passenger side stays lowered.

Cheers Greg

 

[Sp!ke]

Not knowing how the system works, I'd take a stab at there being a pressure regulator or valve that is faulty throwing off the balance. With the engine running the system compensates.

 

[mercedescl500]

This is what I would try first. First try and borrow an ABC ecu from another car and try and get the same symptoms. If no symptoms occur then you need a new/2nd hand unit. The ABC ecu do suffer failures. Secondly it takes 30seconds after you turn the car "off" for the ABC unit to fall asleep, check to see if the unit is awake after 30 seconds. If its still awake then you need to look at this being switched "off". This is where I believe your problem is. HTH.

 

[mercedescl500]

This is what I would try first. First try and borrow an ABC ecu from another car and try and get the same symptoms. If no symptoms occur then you need a new/2nd hand unit. The ABC ecu do suffer failures. Secondly it takes 30seconds after you turn the car "off" for the ABC unit to fall asleep, check to see if the unit is awake after 30 seconds. If its still awake then you need to look at this being switched "off". This is where I believe your problem is. HTH.

Also disconnect the ABC ecu and check all pins have no oxidation (green/blue powderish residue). The pins can also require resoldering.

 

[SavMan]

Is there any way to bypass the lowering module, some come with a jumper lead. That way you can at least diagnose on a stock system.

 

[mercedescl500]

Also try dropping Malcolm (Television) on the "other" forum a message/PM. He has re-soldered r230 ABC ecu before. It would definitely be worth a try.

 

[redbaron]

this thread makes me glad i went down the links route... (though i was less glad when a link popped off that i didnt click in to place properly....)

 

[AndyPCD]

I was thinking on the same lines as paul. Disconnect the lowering module and see if it still does it.

 

[BaldGuy]

Many thanks for all of your help....

Disconnecting physically is an hour or so's nightmare... I can however turn it off from the remote and it reverts back to standard height. Will try this tomorrow and monitor

Cheers Greg

 

[BaldGuy]

Ok..... with the module off it reverts back to standard height... although drivers side too high or passenger too low.... There is obviously something wrong!!!

 

[BlackC55]

I'm in agreement with the pressure sensor. They are a few quid though as they come with the Accumulator too now.

FYI the level sensors are all within spec.

 

[BaldGuy]

I can physically see it raise on the drivers side when i switch off and get out.. within a minute.... and NO im not fat!!
Switch back on and cycle the suspension height, switch off and get out n lock.. it stays low.... weird...

 

[mercedescl500]

I'm in agreement with the pressure sensor. They are a few quid though as they come with the Accumulator too now.

FYI the level sensors are all within spec.

There is a repair kit available for the accumulator body/sensor.

http://www.mbpartsworld.com/p/__/REPAIR-KIT/7903011/2203201158.html

 

[mercedescl500]

I can physically see it raise on the drivers side when i switch off and get out.. within a minute.... and NO im not fat!!
Switch back on and cycle the suspension height, switch off and get out n lock.. it stays low.... weird...

I'd still go with the ABC ecu being faulty and not a accumulator pressure sensor fault. Good luck