A complete new kind of self-level suspension mystery

[X54L1FE]

Hi guys,

My ride's a E53 4.8iS, (11-2004) with 111k miles. Since months I noticed strange behaviour in the car's stability when driving;
it reacted like a wobbeling truck on the slightest changes in the road. I discovered the different measures in wheel height, everytime I started the car.

When pushing the up or down button, the SLS system mostly didn't react within 1-2 minutes, followed by a short inflation, then stopped.
The result: front standing in a high position, rear still in mid or even low position, or vica versa.

- Many times each wheel measured a different height.

- I have NO error at all on my dash, I never saw anything like 'SLS inactive'

Went to the dealer for a complete SLS check and this is what they said they done:

- They reprogrammed the EHC
- Checked the sensors
- Calibrated the wheels
- System error check: No errors at all
- Air strut check: no leaks
- Replaced the relais that connects the compressor with the EHC
- Checked the compressor for faults

I also asked them why fuse entries 79 and 87 in my fusebox (taking care of air suspension) both miss one pin (see picture). Fuses only function with 2 pins.
They said the postions might not be used. That's not true because another fuse number is actually empty and it has no pins at all.
Taking out fuse 79 and 87 ofcourse have no result.



Dealer said the car's fine, took the car home, the first 3 miles were okay, then suddenly it started wobbeling again.
Went back to the dealer twice but their knowledge is surprisingly limited, they don't like to dive into a specialist problem.

Recently I changed both front sensors, tried to calibrate it with a Snap On handheld system, but the car just doesn't put
itself to the right wheel height. After 4 calibrations the car suddenly got equal on it's 4 sides. After a driving test of 2 miles still okay.
Turned the ignition off, started the car 15 min later and the sound of the compressor told me it would change it's heights again
and everything went back to where it started.

Actually it got worse, because it's now able to self lower it's height to dangerously low positions.

I don't trust the stealerdealer anymore, but the countless stories of people with SLS probs here got me thinking of converting the
airshitspension into good quality coils.

Anyone has a clue?

[4.8isX5]

Wobbling sounds like you have control arm or bushing issues. Air ride can be recalibrated yourself or if you know someone with DIS. You can buy the software and cable yourself if you are IT inclined.

Even if your suspension airs out all the way, all you should experience is a very harsh and bumpy ride, however if the road is flat it will not cause any wobbling as you say.

If the dealer doesnt know what they are doing find a competent independent shop near you and go there.

You can do a quick check for play by jacking the car up on one side (leave other side tires on ground), grab front or rear wheel in 12 and 6 oclock positions and try to shimmy it- should have no play, then do a 3-9oclock position shimmy and should not have play as well.

If your front wheel has 3-9oclock position shimmy thats whats causing wobbling or vibrations. Most likely bad Lower control arm balljoint.

[X54L1FE]

Thanks for your prompt & extensive reply.

I checked the wheels with the 'shimmy shake' but they're all fine. I knew this, because when the car was calibrated well, it drove like new; turns, accelerating, all was just fine. Until you shut down the car and ignite it again; that's when the problems are coming in. During ignition, the car's getting some 'new info' I guess and starts to reset it's wheels and then all driving accuracy is gone.

Today I drove a few miles and the car's steering wheel didn't automatically turn back to it's 12 o' clock position! It more or less stayed in it's last turning position. In the end I'm getting quite desperate: every turn the car makes is a complete mistreatment.

Edit: The missing fuse pins issue was solved a time ago on this great forum.