Mercedes Active Curve System Leak from Oil Reservoir

Mercedes-Benz recalls vehicles (166 and 292 chassis) manufactured from 2012 to 2017 quipped with Active Curve System (ACS). The problem is oil leaking from Active Curve System (ACS) reservoir. Owners of Mercedes-Benz vehicles listed below should call their dealer to verify if their car is affected by this problem. This problem affects various models, including ML-Class, GLE-Class, GLE-Coupe Class, GL-Class, and GLS-Class.

Oil can leak from the Active Curve System reservoir. The vent holes in the cap allow oil to leak from the reservoir. If the level drops below the MIN mark, the oil will foam due to air mixing with the oil. If your Mercedes-Benz has this problem, you may notice oil leaking on the side of the ACS oil reservoir.

The problem is not only the loss of oil, but if the level drops below the minimum level, air starts to enter the hydraulic system. When this happens, air will mix with the oil and create aeration. Not only may you hear a whine (similar to power steering noise), but aeration can cause damage to the components and seals of the Active Curve System components. To verify that you have an Active Curve system, open the hood and determine if you have a reservoir on the left side of the engine bay. The reservoir has a cap that reads Hydraulic Fluid only.

What is Mercedes ACS?

Active Curve System (ACS) is an optional feature on many Mercedes-Benz SUV models. It uses an electro-hydraulic stabilizer to stiffen or relax the stabilizer bars, which can help the vehicle when cornering. ACS is fitted on some vehicles with air suspension. Overall, vehicles equipped with ACS handle better than Mercedes vehicles that don’t have ACS. To have an Active Curve System, your Mercedes-Benz needs air suspension and Adaptive Damping System (ADS). While the ACS system can not exist without ADS, it is possible for vehicles with ADS to not have ACS.

Solution

Mercedes-Benz dealerships will fix this problem as part of the recall simply by replacing the cap for the ACS reservoir. According to MBUSA, the newly redesigned cap had a membrane to prevent oil from leaking. The oil level should also be checked and topped off if it is below the MIN mark. Mercedes-Benz replaced the active suspension oil reservoir sealing cap on nearly 10,000 vehicles from 2012 through 2017.

What Scanner Can I Use to Diagnose Active Curve System Problems on a Mercedes-Benz?

If you’re experiencing problems with your Mercedes-Benz, a YOUCANIC full system diagnostic scanner can help you troubleshoot the issues. This advanced diagnostic tool can read and interpret the fault codes stored in your car’s computer system, providing detailed information about any problems with the engine, transmission, brakes, or other critical systems.

The YOUCANIC scanner can also perform diagnostic tests on various systems, including the ABS, airbag, and steering systems, to help pinpoint the root cause of any issues. With this information, you can make more informed decisions about repairs and maintenance, saving time and money on costly repairs.

Affected Vehicles

MERCEDES BENZ	GL350	2013-2016
MERCEDES BENZ	GL450	2013-2016
MERCEDES BENZ	GL550	2013-2016
MERCEDES BENZ	GL63	2013-2016
MERCEDES BENZ	GLE350	2016
MERCEDES BENZ	GLE400	2016
MERCEDES BENZ	GLE450	2016
MERCEDES BENZ	GLE63	2016
MERCEDES BENZ	GLE63S	2016
MERCEDES BENZ	GLS350D	2017
MERCEDES BENZ	GLS450	2017
MERCEDES BENZ	GLS550	2017
MERCEDES BENZ	GLS63	2017
MERCEDES BENZ	ML350	2012-2015
MERCEDES BENZ	ML400	2015
MERCEDES BENZ	ML550	2012-2014
MERCEDES BENZ	ML63	2012-2015