This sounds similar to whathappened to me this week and now I swear the back looks like it is sitting lower than usual.

2003 4.4i Sport

Re:inactive suspension message
 

Hi,
the inactive message did once come up on mine. Checked the fuse and it wasn't in cos i think some daft BMW mechanic did take it out and forgot to replace it. Insertion of a new fuse solved the problem and its never come on. I suggest you check the fuse or the sensors.

regards

Hi
took my 4.4 sport to the dealer re this warning light. He diagnosed a faulty sensor on the rear left. I purchased the new sensor and bracket from the dealer and fittted it myself. The old rod just needed some lubrication but the bracket had seized onto the old sensor. The job took no more than one hour and was very easy. However I still have the warning light. Will I have to go back to the dealer and get him to reset everything. If so hoping will do this for free as he charged me £70 for the diagnosis. Thanks

Ya mine was fixed after I changed the other sensor. The sus.inact light went out after a couple of starts, I didn't have to get it reset.

I also replaced the sensor, bracket, rod, and even the plug since it was brittle.

Self Leveling Light went off
 

I only got the indicator light one time.

I will take to the dealer and ask them to check the sensor.

Was hoping that was the case have been for a test drive and restarted numerous times still have the light. So frustrating when you fit a new part and still have the problem. Have never had any problems like these on the good old VW Golf TDI

I got the suspension issue today and was told it was my module by the dealer.
But I also have the tail / brake light issue too. The light issue has been there for a while. maybe this could be the fix....
Will check the bulb and see

Having replaced my rear n/s sensor and arm the light did reset itself after a ten mile journey. I purchased the part from the dealer and fitted it myself. A very easy job!!! Mine has 4 sensors one in each corner. I assume by module you mean the part that controls all the sensors. Did they give you a part number for this. I have the etk and tis which assists with identifying parts and problem solving. Am just in the process of replacing all my suspension as at 100k it all is starting to fail. Let us know how you get on.
Rich

The Part Number that I was told is BM37-14-6-773-999
I am not sure if this is the module that controls all four, but I assumed it was looking at the price of $732.66
Where is this part located anyways? Is it behind the glove box?

I have a different part number on my etk however it begins the same. It may have been superseded. The sensors are around $100 each so I would say it is the module. It is located in the rear boot under neath the spare wheel you will see a black round compressor.Upon that is a connection of some sort the end of that is a square control unit which is the module. At least thats how it looks on this pic. This part is fitted to e39 5 series as well so may be able to get one from the breakers. The suspension does have a relay so always check that. Looks like an easy fit maybe just a plug out plug in part. If you have a friend with an x borrow their unit to confirm diagnosis. I never trust the dealers. Hope this helps