Self-levling suspension inactive comes and goes.

[Vega2k]

Hello.

I have a 99' e39 touring and the self levling suspension comes and goes..

Usually when i start the car and then drive out of my driveway, the compressor starts, sometimes it stops quickly and no error message is displayed.. but sometimes the compressor goes on for 1 minute and then the error message appears..

i have 2 faulty codes from inpa.

E R R O R M E M O R Y R E P O R T
-------------------------------------
Date: 04/12/18 22:51:17
ECU: EHC
JobStatus: OKAY
Variant: EHC
-------------------------------------------------------------
RESULT: 2 errors in error memory !
-------------------------------------------------------------
10 Regelzeit, einseitig
Error frequency : 31
unbekannte Umweltbedingung 247.00 XY
rechte Seite
-------------------------------------------------------------
8 Regelzeit, heben
Error frequency : 31
Hoehenstand hoehere Seite 245.00 mm
Stand
================================================== ===========

I do not speak german but with google translate it comes out like this:



-------------------------------------------------- -----------
RESULT: 2 errors in error memory!
-------------------------------------------------- -----------
10 control time, one-sided
Error frequency: 31
unknown environmental condition 247.00 XY
right side
-------------------------------------------------- -----------
8 control time, lift
Error frequency: 31
Height higher side 245.00 mm
Stand
=========================================== ============

Ive checked fuses, they are ok, control unit seems ok.. there seems to be no hissing from the air shocks aswell.

But ye the problem comes and goes.. maybe its the sensors?
when it is working and there is no faulty messages displayed, the height seems accurate on both sides when measuring for the required height.

it was dark and late now this time i decided to diagnose and find those faulty codes, so i could not see if the one side was actually higher, as inpa states..
but one time before, there was only 1 error and it was the same error 10 control time unknown environmental condition but it was the LEFT side.


for now i just took out the fuse for the compressor and disabled the air suspension check control using ncs expert, maybe its not a good idea but i dont want my compressor to burn out..

[Aussie528iT]

It seems as though the compressor is running for longer than the allowable time, which IIRC, is 8 minutes.
Since it is related to the RHS you may have a small leak in the RHS air spring, aux air reservoir or one of the plastic air lines.
Not sure what the second error is but possibly saying that the correct height is 245mm and the RHS side isn't always at this height????
Do they salt the roads in winter in Norway? Could be causing corrosion of the aux reservoir.
The Wiring Diagram System (WDS) has explanations of how the self levelling air system (EHC) works.
Google for WDS and go from there.

[Vega2k]

Thank you for your reply Aussie528iT.

Yes we do salt our roads in norway, which is good for safety purposes but not so good for our car parts.. so theres this downside to that..

Ive searched around for that WDS but all the "good" links seems to refer to the same page (bmw-planet.net) where i get 404 error ..

If i go to plain bmw-planet.net i get the page up and can select desired vehicle but nothing displays after that...

I manged to use old internet explorer which got me a little bit further but i was then blocked out by active control x , i then went into the ie settings and selected bmw-planet as a trusted site, and enabled unsigned active control x installations, but yea when i get prompted to install it nothing happens..

[Aussie528iT]

Another option is newtis.info which has a lot of info:
See link below.
There is also has a reference to the EHC warning light being on intermittently involving K bus errors.
https://www.newtis.info/tisv2/a/en/e...on-ehc/XhQEhZ6
It's also worth doing a visual check on the air springs to make sure the rubber isn't perished and the cotton reinforcing cords are not visible.
If the spring is belled out at the bottom and white tufts of cotton are protruding then they are not long for this world.
This is what happened on my touring and after approx. 140K kms one failed so I replaced both bags.
The original bags were made by Gates but the replacements were made in Mexico by, IIRC, Schaefer International (they bought this part of Gates), and even after 120K kms they are not showing any signs of failure like the originals.

[Vega2k]

thank you for that link!

I didnt have much time before i went to work today but fast inspection using inpa i was tuning the height to see if it made any difference to either side.
Now it appears that the left side works ok but the right side will not rise, it only rises a few cm if the left side is risen.

So obviously the air spring or the rear air reservoir or hoses is faulty.

Now since only the left side is working, should i lower the left as far down so that it will not "carry" more load than the right side? -until i have fixed the right side?

I know i should just replace both sides while im at it but i am gonna sell the car and trying to be friendly to my wallet.

[Vega2k]

its been some months now but i managed to get it sorted out,

turned out that my springs was not leaking, so i decided to move over to the compressor it self.
What i did was to open up the compressor and cleaned both the air valves, put it back together and boom,
no more saggy right side and no more self leveling suspension inactive fault.. and they are still fine 3 months later

[Aussie528iT]

Good to know you got it sorted.
BMW gives the impression that the air compressor isn't serviceable apart from a relay.
It's good to know that other parts can be dismantled and cleaned.
I've never had cause to look inside the housing in the spare wheel well and will store that info in the memory bank.

Regards

[geargrinder]

Nice! Some guy while back found replacement components for the valves I believe. I got the info someplace. And there’s compressor rebuild kits out there for the pump itself. If I ever have trouble I’ll prob look into that.

[msvphoto]

It does sound like a leak most likely. So far the only SRS work I have needed to do on the 540iT is replace bad bags, but I gained more experience than I ever wanted to during a few years of Audi allroad ownership (let's just say you get really good changing bags on those things). Based on my allroad experiences the problem is almost always leaking bags. E39 SRS maybe different that way, but I doubt it.

Geargrinder's tip about a rebuild kit is a good one. The $$$ compressor is pretty much the same Wabco compressor as the allroad (and many others). The kit I used came from a guy in the UK known as Bagpipe Andy via eBay. http://www.bagpipingandy.com/ It was super easy to install. I didn't even need to remove the compressor in the case of the allroad. Time to change ride height levels increased a lot after the kit and I no longer had codes set for the compressor timing out (at least when all four bags were leak free that is).

[rmondell]

Ride Height Sensor Arm Pointed Inward:

If the sensor was working before you did any suspension work, and the wheel carrier was moved up or down significantly, the ride level sensor arm can flip to point inward, causing the self level inactive error. All you need to do is, take the wheel off, support the wheel carrier with a jack and position it up or down to give the level sensor arm some slack, take the lower 10m nut off with a socket while bracing the inner nut with a 10mm spanner, flip the arm to point outward, and reassemble. Tightening torque is 9NM. Clear any faults before driving to erase the error.