What causes "Level Control System Malfunction" when carry heavy weight at rear

[swong11]

Hi, I am new to this group and hope to get some advices on the issue that had been bothering me for many years.
I would like to know or troubleshoot the reasons that causing my 2008 3.0L X5 "level control system malfunction" indicator went off when I have slightly heavier weight on the trunk or had my 3rd row seats occupied.
I bought this car in 2011 as a 3 year old used car. Since then, at the beginning, the "level Control System Malfunction" light went off whenever I have 3rd row occupied, or put luggage in trunk or hung bikes on the hitch/back. There was no hissing sound from air spring or compressor operating sign, the car was not sag, everything seemed normal. But the indicator is ON
Overtime the indicator went off more and more frequent, and seemed like getting more "sensitive". Even I don't have 3rd row occupied, or luggage or bike in the back these days, it just went off when I have 2 passages on the 2nd row seats.
Could this be the sensor issue? Where and how to replace? When the indicator is ON, does it mean the compressor will stop?

Appreciate your advice.

[yco]

leakage can be really tiny that you may not hear that much hissing and since you re saying it got worse over time more likely its a leakage.. it can be airbags, valve bodies or the comp.. there are 2 fuse boxes that controls the level of the car.. one in front passenger side as you may already know and the other one is in the passenger side again right side of the trunk.. and there is a handle that you can take the plastic part of and see the second fuse box for it.. i dont know which fuses are controlling the self leveling but it should be easily found on google or youtube.. you can take that fuse out first from the front fuse box and then one on the back to reset the system.. if one of the fuses are going bad you re lucky already.. it ll force the system to work hard on a short period of time and it can give you an idea..

and there should be 2 sensors.. one on driver side axle the other one passenger side rear.. if i were you i d take out all the trim parts in the trunk and start inspecting in closed garage to amplify the noise.. it can be a bad seal on one of the hoses that can be seen easily or something bigger.. one way another it ll be the best way to start.. but before all that making a scan for faults d be shortcut..

[swong11]

Hi Yco,
Thanks for your advice. I will check the fuses then the noise when get a chance.

Just curious, if there is a leak, if I keep the car idle for 1-2 weeks. If the air bag leaks it will sag after 1-2 weeks. In my case it is not the case. Perhaps the air bags are OK. Could that be the comp or hoses etc (as you mentioned)??? May be when I have heavy load, the rear air bags have large pressure pressing down BUT the comp is not strong enough to inflate it or leak along the path... What do you think?
I will check it out when I get a chance and update later...

Thanks,

[molloy]

Did you ever figure out a solution?

[raysbmw]

Mine was the rear-level sensor. This article explains the most common problems in detail.

https://www.youcanic.com/wiki/bmw-le...re-malfunction