Self Level Suspension Inactive
 

Posted on Facebook but thought I would try here as well.

My rear air bag suspension is no longer lifting on either side of my 2000 BMW X5 4.4i SAV. There is no sound coming from the compressor. I replaced the air springs last year with new Arnott bags. Car has been sitting for 6 months. I know I need to replace the height sensor on the driver side based on what the local indy shop told me from their inspection. I have been getting the "Self Level Susp Inact" dash message all along but in the past the compressor always kicked on and inflated both bags. I still need to check the fuses.

Questions:

1) Is there an easy to bench test the Wabco compressor to make sure it is functioning?
2) Will DIS give me any additional information?
3) Can I use a multimeter to test the height sensors? I have one new replacement sensor.

Thanks guys!

As always, reset the system before anything else. Once the system is back in action you'd most likely find out where the fault is fairly quickly. Also, visually check the height sensor...is it attached correctly?

My guess is your compressor needs a refurb kit due to being overworked as a result of a faulty height sensor.

Good luck!

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How do I reset the system?

There is a very slow leak somewhere in the system I've been unable to find for years. The compressor may be burned out from being overworked but is there some way to turn it on manually and test it? I've seen the Piston ring repair kits but wondering if mine can be repaired since it's not turning on at all anymore...

Disconnecting battery does not reset it. Working on getting INPA setup. Found a write up on how to do the refurb kit and bench test the WABCO. I will likely just pick up the kit the unit is 18 years old now after all...

https://www.google.com/amp/www.instr...famp_page=true

You can only reset the system via a diagnostic tool (INPA, iCarly etc).

Since you've changed the airbags you can eliminate them as culprits (unless you didn't attach the air hose to them correctly?) Next is leaking lines or reservoirs or bad sensors.

Again, reset before anything else.

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Cool. I just setup a WinXP VM on my Microsoft Surface I have a INPA compatible USB cable so hopefully I can get into that EHC module soon and dick with it.

Otherwise a set of coilovers is looking mighty good!

Pulled up the spare tire and compressor to inspect the EHC module last night. As soon as I touched it the compressor kicked in.

Attachment 73079

Attachment 73076

Looks like I have a intermittent connection issue to my EHC module. Not sure why. I do have an extra piece of hardware next to the battery I installed called a battery brain that allows you to remotely disconnect the battery. I think it was pressing on the module with the weight of the plastic cover and compressor on it. I'm going to relocate it to where the tool kit pouch is that sits in the little triangle thing next to the spare tire.

Attachment 73077

Connecting fine now in INPA/DIS:

Attachment 73078

EHC relocated. Seems to be staying connected now with plastic cover, compressor, spare tire and cargo floor reinstalled.

Make sure no water gets in to the area.
My EHC module fried once due to water getting in there.

i have the air suspension module and compressor if you need it.