i think it is in the boot by the battery for sure i have seen bunch of modules there when i cleaned the trunk area. This is the thing about this forum if someone knows something wont share it just visit the site for there convenient. it makes me mad some times all forums are to help each other out while admin makes the money lol but.............:confused:

Correct, the module is in the trunk by the battery. there are some pics a few posts up that show the location.

Don't overlook the pump relay though, it is the most common cause of the inactive message and easily overlooked as it is in the metal hump with the pump.

just found it today:
1.- take out your spare tire
2.- take out 4 bolts that hold the pump
3.- take out 4 bolts that support the pump frame
4.- take out three phillips head screws
5.- remove the plastic shield (held by those 3 screws)
6.- module will be to the right side of the battery

Thanks guys!

I have been having SLS problems on my '04 4.8is for the past 18 months.

An air strut failed (I heard the air escaping) on the front offside and the dealer replaced it (£1000 after a 40% BMW contribution for parts)

6 Months later the SLS inact. light came on again. £400 later the dealer fitted a relay.

6 weeks later light came on again. It's been coming on every regularly at intervals between 4 days and 4 weeks for the past 11 months.

Last week the front nearside air strut completely deflated. Ah another air strut I thought. But after removing it my indy couldn't find an obvious flaw with it so he refitted it and after a reset the car inflated and operated perfectly!

He spent a whole day stripping and testing and all looked good. 1 hr after he left it it deflated again.

The plan now is to remove the strut again and rig it up to inflate out of the car and submerge the strut in a water bath and look for leaks.

Just wondering, did any of you with similar issues ever get to the bottom of it?

Indy is suggesting (one by one in this order)

1) replace air strut if leak is found
2) if no fault with the air strut replace compressor (I can't understand as it's always the front nearside that goes down and after a reset it always works fine)
3) replace control unit
4) replace actuator

If it isn't the strut it could possible be a dirty/corroded valve seat in the valve/solenoid block near the compressor. That could/would possibly cause intermittent/sporadic leak off one circuit. Worth looking into.

Air strut tests and when it was submerged in a water bath no leaks could be found. So I guess that rules it out then

Thanks Weasel for your info - I have relayed it on to my independent BMW specialist and although your theory is interesting he does not know what solenoid block you are referring to.

He says the valve block near the compressor has only one circuit and that leads to the accumulator under the driver's seat (right hand drive). There is then a valve block further forward under the driver's pedals and this is the one that he says controls the ride height at the four corners. Is it this you are referring to? Your post said near the compressor in the rear.

Can you expand please as it's an interesting theory which may explain my issues.

The faults that keep recurring are; a cam bus error and constant request for filling

Thanks

I was a bit distracted... the setup in the rear is just for the rear axle, and the setup in the front is for the front wheels naturally. As long as the guy is well versed in the system he should be able to figure it out, it is just a matter of testing different things in the system that can cause the symptoms. Air is leaking out somewhere, just a matter of finding where.

Thanks Weasel

Unfortunately not that simple. There is no leak. Everything's been pressure tested at least 6 times by local BMW dealer and independent specialist.

It seems as though it's an intermittent control issue.

Ride height sensors have been replaced all round so it now seems as though I may have to bit the bullet and change the control module £760 although from the BMW diagnostics, for the errors that are being thrown up the BMW manual suggests changing the compressor and control module.

That's one expensive repair to try to eliminate a fault that might not actually lie with either part

Thanks anyway Weasel

my problem was water in the battery box that messed with the self leveling relay down there. blew up the radio and killed the battery. better check for water.

To the best of knowledge, finding the module, which is located next to the spare tire, will not help you much as since you have to reprogram it. I would consider finding an independent European mechanic's shop who know what they're doing.

The rubber air bags are typically used in the rear. I recently bought a set and couldn't find them in the aftermarket. Went to the dealership and used the cca menbership card for a discount.

I highly recommend using a shop repair manual for this work. It was not the easiest job in terms of troubleshooting.