SL/R230: ABC Red Light on & off
Thread Starter
Newbie
Joined: Mar 2022
Posts: 4
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sl 550
ABC Red Light on & off
My 2007 SL 550 suspension became very soft and it is bottoming down at every bump on the road.
The heights are fine, and while parked it stays at the proper heights, it raises and lowers fine ..........it' s just very soft !
Any advice ?
Thank you
The heights are fine, and while parked it stays at the proper heights, it raises and lowers fine ..........it' s just very soft !
Any advice ?
Thank you
Senior Member
Joined: Apr 2007
Posts: 436
Likes: 79
Former R230, W220 and W221 owner
There's also a pulsation dampener- on the 2007+ models- it's attached to the ABC pump. For this you would hear a humming noise
https://www.fcpeuro.com/products/mer...eco-2213280015
https://www.fcpeuro.com/products/mer...rteco-80001407
Also, save this to your favorites- it's EVERYTHING you would ever want to know about ABC
http://mercedes-abc-drive-carefully.blogspot.com/
Last edited by imtheking; Feb 13, 2023 at 03:12 PM.
Senior Member
Joined: Apr 2007
Posts: 436
Likes: 79
Former R230, W220 and W221 owner
Also, another symptom is that the reservoir under the hood will overflow and get ABC fluid all over the place.
From the ABC bible (this happened to me)
If an accumulator has failed, the accumulator will fill with hydraulic fluid and the air will begin to work its way out of the system. While this process is occurring, the free air in the system expands whenever the system depressurizes, pushing fluid to and out of the reservoir. The fluid level in the reservoir will drop during this phase. Eventually all the air gets out, and the overflow behavior will cease. But by now you should be getting very frequent "Drive Carefully" messages on the dash due to the lack of available accumulator pressure to help fill the struts. The air in the accumulator has now been replaced by fluid, and it cannot accept any more fluid when the car is started and the system pressurizes.
Get these accumalators replaced ASAP. It's a wear and tear item. Parts are not that expensive and a good mercedes mechanic should be able to replace these in about 2 hours. I did mine myself and it was not that bad. Could have done it quicker if I had a lift
