Self Leveling Inactive

[dannyzabolotny]

I just finished redoing my rear suspension last week, and as soon as I got the rear wheels back on the ground I got a "self-level inact." message on the cluster. My first instinct was to hook up INPA and clear the self leveling system error. That worked for less than a mile, the error came right back after a little bit of driving. It hasn't prevented me from driving the car the past week since my airbags hold air pretty well.

Last night I tried swapping out the rear right self leveling sensor, since that's what INPA indicated as the source of the error. I used a sensor from a 2001 540it parts car that's in my backyard. After swapping the sensor, I still got the same error:



I cleared the error again, drove the car a few blocks, and then there were two errors.



Is it possible that both of the sensors are bad? Or might my issue be in the wiring between the sensor and self-leveling module? I can't imagine why that would have happened, I didn't even come close to those areas when working on the suspension. All my fuses are good as well, that was one of the first things I checked. I can still manually raise and lower the rear end with INPA so the compressor still works fine.

Any ideas?

[jclausen]

I would recheck the area for something out of place first, then start dx, if the sensors could be swapped that might be a good idea

[dannyzabolotny]

I would recheck the area for something out of place first, then start dx, if the sensors could be swapped that might be a good idea

I already swapped a sensor in from a different car... no change. I read that these are hall effect sensors and not potentiometers, so it's hard to imagine them breaking unless they're physically damaged (which they're not). That makes me wonder if it's an electrical issue.

I checked in INPA and the system isn't in transport mode either, as I've read that can cause issues. I did leave my 540it with the rear end hanging down for the better part of a week when I did the rear suspension work, wondering if that affected anything.

[BimmrMeUpSnotty]

I'm thinking harness. How does the silicon seal in the plug look? Do the contacts look free of any oxidation? Wires look ok?
Man, all the problems I see with these rear airbags, I'm kinda glad I have coil springs in mine. But.... it does droop when I have a ton of crap in the cargo bay with the seats folded down, but I have never bottomed out when it was. The car actually rides very well fully loaded. I love my Snot rocket green wagon!

[dannyzabolotny]

I'm thinking harness. How does the silicon seal in the plug look? Do the contacts look free of any oxidation? Wires look ok?
Man, all the problems I see with these rear airbags, I'm kinda glad I have coil springs in mine. But.... it does droop when I have a ton of crap in the cargo bay with the seats folded down, but I have never bottomed out when it was. The car actually rides very well fully loaded. I love my Snot rocket green wagon!

The plug looked fine from what I could tell. It's been a CA and AZ car since day one so there's no rust or oxidation anywhere. I guess I'll try doing some continuity tests from the plug to see if there are any shorts in the wires.

Aside from this issue, I haven't had any issue with the rear air suspension. I like that I can easily change the ride height with a laptop, and I like how I can load up the rear of my wagon with a ton of heavy stuff without any sagging. I eventually want to install a towing hitch so I'd like to keep the self-leveling system.

[BimmrMeUpSnotty]

Tow hitch, well damn, yeah, those airbags are awesome for towing. What are you gonna be towing?
Just had an epiphany.... Get a second touring with a blown motor and drivetrain, chop the front end off, cover up the front end, weld on the front end of a trailer, braced properly, paint the wagon same color as the car pulling it, That would be a cool sleeper trailer.... Yeeeeah!

[dannyzabolotny]

Tow hitch, well damn, yeah, those airbags are awesome for towing. What are you gonna be towing?
Just had an epiphany.... Get a second touring with a blown motor and drivetrain, chop the front end off, cover up the front end, weld on the front end of a trailer, braced properly, paint the wagon same color as the car pulling it, That would be a cool sleeper trailer.... Yeeeeah!

What am I going to be towing? Whatever I want, haha. I just want to have the ability to tow stuff after I sell my X5 4.6is. My buddy has an open car trailer that I can use for towing cars, and I can always rent an enclosed U-Haul trailer for moving purposes or for transporting large furniture. I basically want my wagon to be the best all-around car that it can be.

[dannyzabolotny]

So here's the weird thing... this morning before work I measured how low the rear was sitting, and it was so low that I couldn't get more than one finger between the wheel and fender in the rear on both sides. But after driving it to work, I can easily fit two fingers between the wheel and fender. I know it's not a super scientific form of measurement, but clearly the self leveling system is sorta working, at least initially when the car starts. The self leveling error comes on about 10 seconds after the car is turned on, which gives it enough time to raise the rear end to a pretty normal height. I haven't bottomed out or anything, despite driving the car constantly with the error.

So now I'm wondering if it's a bad sensor that's causing the system to become inactive (one of the errors did say "measuring range not valid"). I'm still going to test the plug on the sensor for continuity just to rule that out first.

[schatzy62]

If you have not already read this thread it might be helpful.

https://www.bimmerforums.com/forum/s...g-gone-bonkers

As for the overnight loss, if it is happening every day the above thread is all about that.

As for the height sensors there are 2 different parts one for Halogen headlight cars and one for Xenon headlight cars. I am not sure what the difference is but they are spec'ed as being different. Also they can be damaged fairly easily if not disconnected and removed while doing rear suspension parts.

If one or more of the sensors, solenoids, hoses, accumulators, and pump is not operating properly or is leaking then it can trigger the notification that the system is not working even if it is partially working.

One other thing to check is if it is the same height from side to side. If it is not that can also trigger a notification. You can measure fron the bottom of the rim to the edge of the fender well and they should be within less than 1/2 different inch side to side. Depending on what suspension is in the car as to what the actual measurement should be.
Disregard the part that says 10mm (.04") it is supposed to be 0.4 inch.20170914_223729.jpg
20170914_223636.jpg

[dannyzabolotny]

Ah, well that might be how I damaged it. I forgot to disconnect the sensor when I was doing my suspension refresh, and the job involved pulling the lower control arm down and under the spindle to access the lower ball joint. And I left it like that for a few days. Now I'm wondering if it really is a sensor issue. The parts car I pulled the sensor from was having all sorts of issues too, like the rear end never stayed up, so perhaps that sensor was damaged too. Given that new sensors are relatively inexpensive, I'm tempted to try that before I do anything crazy.

[dannyzabolotny]

Just to wrap this thread up, I fixed the problem. I ordered a new OEM sensor from AutohausAZ, it was something like $60. It's literally the same sensor as the OEM BMW one that I removed, just with the BMW logo ground off. Curiously enough, the sensor that was originally on this touring was from 2009, so I guess it's not unheard of for these sensors to fail. I swapped over the little bracket and sensor arm from the old sensor, and then I installed the new sensor.

Initially when I started the car I got the same "self leveling susp inactive" message, but after driving the car for a few blocks around my neighborhood the error went away and never came back. I guess it needs a little bit of driving to reset itself. The rear end is sitting pretty level now, so problem solved!

tl;dr: I replaced the sensor, that fixed the problem. I guess I had two bad sensors (the one on my touring + the one from the parts car, both were bad).

[schatzy62]

Glad to hear you got it all fixed up.

[dannyzabolotny]

Yeah, I'm glad too Thanks for the tip about the sensor, I'm glad I tried buying a new one instead of doing something drastic like taking apart the whole rear wiring harness.

The car didn't drive any different with the self leveling system inactive, but having any error messages on the cluster is irritating to me. I like to update my threads with conclusions because I've always been really frustrated with finding unfinished threads about similar issues.

[schatzy62]

Yeah, I'm glad too Thanks for the tip about the sensor, I'm glad I tried buying a new one instead of doing something drastic like taking apart the whole rear wiring harness.

The car didn't drive any different with the self leveling system inactive, but having any error messages on the cluster is irritating to me. I like to update my threads with conclusions because I've always been really frustrated with finding unfinished threads about similar issues.

Totally agree with the frustration on others not posting their final outcome.

I used to get random and I mean very random inactive messages. They would always go away with a engine restart. Never found the problem. But never had an issue with it leaking while the messages came up. Then when it started leaking the inactive messages stopped. Took 6 winter months to figure out it was the solenoids connected to the pump.

[esthero]

how many level sensor is there on our car? one in the front and one in the back? did you replace them both or just the rear?

[dannyzabolotny]

how many level sensor is there on our car? one in the front and one in the back? did you replace them both or just the rear?

On my car there are 3. One in the front that's used just for the Xenon headlights, and then two in the rear that are used for the self-leveling system and maybe also the headlights. I just replaced the right rear sensor, because that's what INPA was showing in its error messages.

[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.