Suspension leveling message

[rockin1978TA]

My 89 535I, keeps giving me a Suspension Leveling message after driving for about 10 minutes. I looked underneath the car many times, and I've never seen any airb bags or mechanisms to level the suspension. How can I tell if my car has this, and what causes the message to come on?

[genphreak]

The rear shocks are hydraulic. The system is simple, effective and very nice when it works. People don't like leaky old pipes and replacing the nitrogen bulbs (pressure accumulators, aka 'bombs'), so they often loop the pipes from the pressure pump and fit normal shocks. However both the upper mounts and springs are slightly different parts.

All one usually has to do is make sure the bombs ($135 ez new) and shocks work (if not just replacing the o-rings can be done if you can find the right ones), ensure the piping system is not leaking and is using the correct synthetic fluid (CHF11S 'Pentosin'), unless yours uses CHF7S non synthetic, which can be replaced with CHF11S.

The message is triggered by the height switch which operates against the rear swaybar. Incorrect fluid type and level, a failed bomb or shock or physical damage to the switch assembly or its wiring can cause your error to trigger. Check the online parts manual for your exact car, or other repair info to see the exploded diagrams of all the LAD/SLS rear suspension parts.

[ss2115]

Hi. I've just been reading up on the LAD systems as I have a problem with excessive camber in my own 525 Touring, and I think I "may" have the answer for you.

Whether you do have the Self levelling, or even if its been taken off at some time and replaced with a standard set up, these suspensions had a Excessive Camber switch that detects a rear wheel camber of -3.5 deg or more.
Its mounted on the right rear axle support and attached to the semi-trailing arm by a rod.

The electronics reading it have a time delay of 8 minutes to prevent the warning being displayed whilst driving through turns.
*This equates closely to your 10 minutes of driving.

What this means then (if this is the reason) is that your rear suspension has sagged. It may be because the selflevelling has stopped working, or it may be that the springs have sagged if its been replaced with standard struts.
Or you might be carrying an excessive load on standard struts (because if the self levelling was working, it would compensate).

Not saying its definetly the answer, but its worth looking into because it matches your symptoms.

[rockin1978TA]

Well I did replace the front struts, and you can tell the back is sagging. It appears the car has struts, but how can you tell the differnece?

[ss2115]

If the self levelling struts are still in the car, then at their base (the lower join next to the wheel) there will be a shorter cylinder next to the main cylinder that is the bottom of the strut.
There should be a hose (like a brake hose) coming out of the smaller cylinder.

The other clue is that up under the body cavity over the diff, you should see two roundish metal bulbs with hoses and a pipe coming from them. These are what everyone in the BMW world refer to as "bombs". The correct term is a nitrogen sphere.
(Mind you, these could still be there even if someone has replaced the SL struts with normal stuts and they just didn't bother to dissassemble and remove the entire self levelling system).

If you've replaced the front stuts, did you put the same springs back on?
If its all new up front,and you didn't lower the ride height and the back is obviously lower than the front, then you would expect the camber on the rear wheels to increase as more weight is shifted now to the back suspension and the rear wheel will flair outwards a bit more.
This would occur even if you do still have the self levelling as the valve that controls the pumping up of the struts will still be seeing the same adjustment on the rear sway bar that it always has - its just that the car has been "tipped upwards" at the front.

You'll probably notice considerable rear tyre wear on the inside edges pretty quickly if not attended to.
You could always get a 4 wheel alignment to check it out - don't let them make any adjustments as it will be a waste of time, but get them to give you the readings front and rear. If my idea is correct, I would expect to see some increased castor on the front (and possibly an incorrect toe in/out unless you had it adjusted after fitting the struts) and increased camber at the rear wheels and its toe in/out probably incorrect as well.

Basically, you need to get the car back to its correct ride height, or at least to the same angle if you've lowered the vehicle, and then you can get the wheel alignment back to normal and get rid of the levelling message. If you've lowered the vehicle, you'll need a rear camber adjuster kit if the car hasn't already got it oem. (mine doesn't, but I think most 535's did - or it might have been all M5's - not sure).

[ScottyWM]

There's a picture of my self leveling shocks in the trader section:
http://www.bimmernut.com/forum/showthread.php?42201-Used-Self-Leveling-Shocks-amp-Springs&highlight=self+leveling

They're still for sale by the way...

[shogun]

In case the car never had LAD, which I assume on a 34 535 anyway, then the CCM is defective and has to be resoldered as shown here
http://www.e34-welt.de/tips_tricks/Reparaturanleitung%20CCM%20e34%20e32.pdf
Sometimes when defective the ccm spits out warnings on parts which are not installed in the car, or even which were never used in a car series.
For example the message ESD regelt. An electronic slip differential was never installed in an E34, but the ccm already had such additional check system.
Some items never made it into series on the E34, but the CCM was ahead of that development and was prepared for such a case.