The troublesome "self level susp inact" error

[Gareth83]

Hi all, firstly I would just like to say this is a really great forum and I've learnt a great deal by reading through various posts, so thanks

[themoog]

The chap who did my central locking a few weeks ago- and he really knows his stuff- said that the most common fault on the air suspension is the air bags leaking at the top where the clamps are. I would check those again.

[Gareth83]

I've checked the airbags and their connections and they are fine, I need to know what would cause the compressor not to kick in when I know the compressor is working. A wiring diagram would help

[Gareth83]

Are there any methods for testing the suspension ECU/ Module part no 37141092396 other than changing it out and seeing if it works?

[chrisn7]

Hi Gareth, sorry to hear of your problems. If you have single axle air,the module is by the battery, under the spare wheel. If you have twin axle air, the module is behind the glove box.

Since you have noted water in the spare wheel well, I would take this out and see what the situation is, as the battery box could well contain water and the air module is not the only module there. From your description it sounds as though the air module has been affected by water, so you also need to trace the leak.

[Gareth83]

Just took out the battery and there was a small amount of water in the bottom, I'd say about a cup full. Where would I find where the ECU modual is located, I have the single axis and know the modual is In the boot near the spare but can't locate it

Thanks

[Gareth83]

Ok I've located the modual and its soaking wet, opened it up and the board is fried, so now I'm sure I've found the problem but need to know why & how water is getting in?

[X5Sport]

Could be the roof drains are blocked, or rear light seals have gone, tail gate seal leak, missing boot plug.  The battery should also have a vent pipe connected - though that will not generate that much water.

[Gareth83]

Well the tube from the battery to the venting plug is missing, but like you said I couldn't imagine that letting that much water in, everywhere feels and looks dry with the exception of the battery bay & modual casing.

Once I've fixed where the water is coming from and the new ECU turns up is it just a case of plugging it in and that's it?

[X5-D-Sport]

Firstly... strip the boot out & dry it out... incl the pockets n front of the tail lights & under...
If you have no sun roof, then the fix is simple.... and 3 places where water gets in...

Ensure you have a proper vent tube for the battery exitng the vehicle floor... the gasses are exceptionally lethal to electronics..

Re your soaked module, the pcb will have become hydroscopic.... so put it on an imersion tank for 24 hrs to thoroughly dry & then spray with Switch Cleaner spray from Maplin to repel moisture & refit to vehicle, you may be lucky & it still works.

If you have a leaking Valve block, I have an easy fix for that... laters.

1.. remove both tail light clusters... 2 x 8mm or 10mm nuts hold each on in place, remove & THOROUGHLY CLEAN THE SEATING SURFACES - rubber strip on lamps & metal flat areas on car body, put a bead of Black gutter sealant on the mating surfaces from B&Q, refit.... solved now.
2..open upper & lower tailgates....thoroughly clean rubber seals & all mating surfaces... baby wipes do this well...
There are rubber seals that seal between the upper & lower gates... this is the likely water ingress point.
Get some silicone spray lubricant & liberally apply wth a cloth to seals & mating surfaces, also noting that debris accumulates around the seals to body areas - clean this too & squirt lots of slicone spray in there too...
3..How tightly does the lower tailgate lock into place ?... the seal around the lower gate is firmer then the upper seal strip.... and will memorise to the pressed shape eventually, so some adjustment to both latches is often necessary to pull the gate tighter to the seal strips.

This should solve your problems.
The silicone lubricant trick is worth doing on all doors too.
Regards
Grant.

[Gareth83]

Great help that Grant thank you sir, I shall dry out the wet areas you mentioned especially the pcb and I'm praying when the new ECU arrives tomorrow it will work, fingers crossed.

[chrisn7]

While you are doing all this, also remove the small rubber plugs along the bottom inner edge of the tailgate, These have small drainage slots in them to allow any water out that gets in to the tailgate, but are so small they can easily get blocked.

Also note the two large holes each side of the upper tailgate hinges which are the rear sunroof drains.

There is also a drain below the fuel filler-make sure this is clear too.

There are 2 'Stoppers' in BMW speak that are spring loaded and support the upper tailgate slightly open, mounted in the vertical gutters each side. Nip these up if required as there is a seal between these and the gutter.

[Gareth83]

Thanks for the advice Chris will check these out

[Gareth83]

So happy  plugged the new modual in and within seconds the compressor kicked in the rear of the car came back up and it drives like a dream again .

I believe I've also resolved where the water was getting in from but will keep checking the boot well to be sure.

Thanks for everyone's advice & help

[chrisn7]

Could you tell us where you think the leak was - its useful to add to the knowledge store?