Self leveling suspension question
 

Hey guys, first off thanks for all your help on other issues. As you know I picked up a 4.8is and have a few bugs to work out..

Bluetooth..another thread

Now the self leveling inactive message....

So last night I work with my friend who is a BMW tech...my car is not losing air, the car stays at the same position overnight..we tested the values on the sensors all looked good, 3-4volts, Except for the right front which was at 1:09.. I thought that was odd, also with the car up in the air we noticed that same arm was basically flipped backwards..we thought that was the issue. We reset every thing, we manually filled each corner, with success, and calibrated the suspension. All was great, I drove about 39 miles, and boom it popped back on..called my tech back he is stumped ( we are going to keep at it) but wanted to see what was going on. I hooked up my BMW 1.4 scanner and I did read a fault, we didn't see last night.--- "RESERVOIR PRESSURE REMAINS CONSTANT WHEN FILLING OF RESERVIOR IS REQUESTED"

So my question to the experts here...what does that mean? The accumulator had 14 bar of pressure,again everything seemed to operate correctly?

And yes I have searched, and I have done all my du dillegence, we are just stuck..car rides good, doesn't loose air, the ride height button blinks when I tried to raise or lower the car....:dunno::dunno::dunno::dunno:

Please help if you can...thanks

Seems like your pump is weak. Does it seem to run a lot? It should not run normally.

Also, this and your ULF module causing issues, have you really checked your battery and alternate. Strange shit happens to our cars with bad alt and or battery. Read my sic to unlock your obc and monito voltage.

Ok I will check...I just went out again..cleared the codes took the pump out of dome. It is coming on. But when I press the lift button or the lower button, the pump runs. But the car doesn't do anything???:dunno:

Last night we were able to lift each corner manually...wtf? This SLS sh*t is for the birds..if I had leaks wouldn't my car sag, some where? I took measurements and will measure again in the morning to see...

27.5 inches rear

27.25 inches front. Measuring from bottom of rim...

I am stumped..

Yea pump seals might be shot. There is a rebuild kit on eBay. Search here for air pump rebuild links.

But why could we lift the car manually last night? If the lump was shot...it was slow...

Ive programmed a bunch of different E53s with 4 corner leveling, if everything isnt working right you can get finicky issues as the one your having.

Ive delt with 2 having the same issue as yours. It most likely is a weak pump and on one of them this "workaround" worked, on the other it threw error 2 days later and was out of spec again.

Program the ride height to where you want it and dont mess with the offroad mode and access mode on the button by leaving it be. As long as your bags arent leaking a bunch if you program it and the system maintains the correct level then your good for a while or until you get a chance to rebuild the compressor. From the one it did work on its been maintaining the height fine (been a few months now) since i calibrated it cause it was all off after a shop had it and couldnt get it level all around.

Because lifting one is not like lifting all 4. Temperature swings can close up leaky seals too. Who knows why. But seems your pump is limp.

That exact code is the pump seals being shot - you need a rebuild kit for the compressor or a new compressor - was my same issue I chased for 6 months about 4 years ago - EHC 74 right?
It will pump up manually but be slow - the module needs to see it working within a specific time frame/pressure, if its too low it will throw that code and deactivate.

Rebuild or replace the compressor, clear the codes, and have working air suspension. Period.

:iagree:

What everyone's says.....and everyone of us had that "SLS" issue.

You're compressor needs attention.

Simple and easy fix.

Sweet! And yes correct code. Anyone in Atlanta have a working pump they want to part with? I would love to fix today!!
Today

just some FYI about the pneumatic single & dual suspensions: (the dual axle diagram is reduced/smaller than the single axle only so that both diagrams fit equally...because all the stuff under the dome in the rear is actually the same size whether single or dual system...and so are the shocks respectively)

Well I can clear the codes and get the pump to work. When I hit the level switch the lights blink. Sometimes it raises the car some times it doesn't. Seems the front raises but the rear doesn't. I will get a rebuild kit and see
If it fixes it. I took the pump apart the cylinder walls looks ok. The little plastic gasket looks worn and has some nics. Nothing that I see that would cause issues, but i willing to try anything at this point

I also reset the unit...just to tell step by step

So I have been driving around and the pump comes on but I see no movement. But no fault either? I press the ride height buttons and still nothing. Even when I press to lower the car, I can hear it hissing, but the car isn't lowering?!?!? Could this be the Control module and weak pump? This is really frustrating

Also I tested my battery 14.1volts at idle So we are good on that front

Just my 2 cents.....I recently had similar problems. My led switch wouldn't work. When I went out in the mornings the front left would be down. This actually triggered the SLS Inactive warning. I had a leaky airbag. Replace bag and still had the warning. Car didn't leak down anymore but warning still there and led switch lit, but still not workings. Replaced my EHC module coded to car, took about 10 minutes and error message Gone. Switch works now and no more SLS Inactive warning. Not cheap, but did solve my problem.

Update:

I took the pump apart and cleaned it, fiddled with the round piston gasket, lifted the small gaskets cleaned it, put the pump back together, I have driven 100 miles no error (knock on wood) the rode height adjuster button doesn't work correctly..only the front of the car lifts, the back doesn't, the pump runs occasionally but not excessively. I am going to get my guy to calibrate it and see if we can trouble shoot some more..but my inactive light is gone...for now..again knock on wood..just providing a update

Just an FYI.....I purchased a control module for what I think is a dual air suspension I think it is only for a two axle car...can someone verify this part number? It shows for a 4.8, but I can't find the same looking module. 37146874414

The 4.8is only came with dual axle self leveling...so a quick diagram look up on realoem.com should give you the part number you need. The number you posted...when entered into the part number search pulls up the 4.6 is...since that model came with rear single axle only...that wouldn't work for the dual axle.

I used a 2006 4.8is with a 1/2006 build date to pull up the diagram: RealOEM.com - Online BMW Parts Catalog

If you click on the 11 digit part number at the link above...it will show the old part numbers that this latest number supersedes. So if your looking for used ones...those other 3 numbers would be the ones that are compatible.

Sorry I wasn't clear, but you answered my question and sorry I wasn't clear..thanks


Well I have a good working control module for sale?? 300.00 what I paid for it...

Ok, well I Took the pump apart and cleaned it. it lasted about 350 miles...now the light is back on. So I deal with it. Fast forward to last night. I went in VW Audi and bought a pump rebuild kit ( part number from a vendor) not a plug and play but should work..i take everything apart to put on the new kit..and get everything back in the car...now no power..I hook up my test light and test the plug that you plug the air pump into, and nothing. Check all three fuses ( 2 in back one in glove box) all fine, did I blow my control module? Why is there no power at the plug? Any help would be great. My shocks are holding air, and seem ok, but I am considering converting to coils and selling all of this shit, this has been a nightmare....blah

Thnaks for any help..

I converted mine even though I didn't have your type of issues....mine were easier to solve but just got sick of doing it all the time. Besides, doing the math, it would be A LOT cheaper to convert to standard suspension (in the long run). My 2 cents....your call :)

BMW X5 4.8iS 2005

Honestly I want to sell the X5. I just picked up a E55 AMG WAGON and love it..the X5 was fun but this air shit has really driven me nuts..I know I am mad right now but stillll..:(

Let me know if there is something I can check to get this fixed...thanks

Cool car!

What year please?

2005. It can be yours ;)