Another Air Suspension Issue!!!

[Bluemike28]

Hi All,

First time posting on the forum.

I picked up a 2017 F15 40D back in November and all was lovely for the first few months. I have the 3rd row variant with the rear air suspension system and hadn't noticed any issues till recently. Started getting the "chassis function restricted" messaging on the dash and center screen. Local shop ran codes and reported back 480DB1.

After doing some basic homework to get up to speed on the system, I am venturing to guess the fault is likely the vent portion of the compressor assembly?

Observations about the car currently:

1) No sagging of any kind
2) No sound observed from the compressor (although I wouldn't expect to hear it if the issue is a lowering function)
3) On pre-purchase inspection, it appeared the car had new air springs installed
4) Both fuses in the trunk are ok and not blown. Have tried pulling them and reinstalling as well while the car is running, no change in code status

So....to my questions:

1) Are there other possible culprits for my code besides the vent valve on the compressor assembly?
2) Is there a good reference to a diagnostic tree someone can share with me that I can use to troubleshoot?
3) If I am going to attempt to service the compressor assembly, do I absolutely have to have ISTA D or can this be done without?
4) Follow on to servicing the compressor assembly and assuming no ISTA D, I am guessing the suspension will drop as soon as I release the red and blue air lines from the compressor. Do I need to support the rear with a jack or jack stands to prevent a drop? And in turn, when I reconnect the air lines, will the vehicle automatically refill pressure to the system?

I really appreciate any help and guidance to the above!

Mike

[Bluemike28]

Bump

[tlow98]

1/2) use BMW TIS to diagnose/troubleshoot.
3) can be done without no problem. Just release the air.
4) yes, support is a good thing. Also, it’s really hard to get a jack in there if you don’t. The system will automatically refill. Best to have it supported so it doesn’t have to pump it all the way up in one go.

I’d prolly pull the stock compressor out and inspect everything. And just order a spare to swap in, bc more than likely your compressor is full of corrosion which is causing the error.

Do you live in a humid/moist climate? Normally accelerates the wear/issues

[shimmy23]

i would go this route too. hate to throw unneeded $ at it but might be good to have a compressor ready to go in since you'll be removing the old one to inspect

[tlow98]

Originally Posted by shimmy23

i would go this route too. hate to throw unneeded $ at it but might be good to have a compressor ready to go in since you'll be removing the old one to inspect

OP can always return the good unit if it checks out, too. I just dislike doing jobs twice. Sometimes it’s unavoidable, of course

[Bluemike28]

Very much appreciated the replies!

I am definitely thinking about going ahead and just picking up a replacement unit as a whole as the underlying issues may cause repeated failures down the line.

If I decide to get a replacement assembly, is there a good aftermarket alternative or should I just go ahead and spring for the OEM unit?

[tlow98]

I’d prolly go with the Arnott P4341 on Rockauto as Arnott is a big player in air suspension and have a great reputation. Specifically made for the x5 and even comes with the right bracket.

Has a 24 month warranty. For $450 what more could you ask for. I’d be tempted to just plug it and see what happens. Not even bother trouble shooting the OE one.

Which is not normally the way I like to do things, but I took my OE compressor apart to replace the beads and man that pump has a ton of moving parts. Lots of ways to fail. Could be trouble shooting a lot before getting it right.

A lot of these pumps develop issues bc moisture saturates the beads and parts start to corrode. Once that happens I wouldn’t trust the unit much longer.