Replacement of Air Supply Device (air pump)
 

Hi all! Recently my car received 'Selflevl Susp. Inact' error message once. I tried to press the up and down button of air suspension and the light just flashed 3 times without action. I used DIS to check the fault code, it says something like 'accumulator ... remains constant...', actually I don't remember the exact words. I cleared the fault code and the car comes back to normal without the fault code. After having cleared the fault code, I also tested the up and down botton and it works normal. Just wonder does this mean my air pump is about to fail or just some kind of computer error (nothing needs to be done on this)?

The accumulator filling pressure remains constant error is related to your compressor. Over time the seal on the piston gets worn out.

Search eBay for "wabco rebuild kit" on eBay its a 50 dollar preventative fix.

Here is a how to:
Bagpipingandy-how to fit Range Rover, BMW, Wabco air suspension compressor repair kit - YouTube

thanks for reply!

The pump now works normal after I cleared the fault code. I will keep my eyes on it and replace it when it stop working.

Happened to me and everytime i cleared the code it came back. That is how i knew something was wrong. I "rebuilt" the compressor with the kit mentioned above by Ricky Bobby and so far so good. This was done last week so im still watching it.

Hi all! Just an update on my SLSI problem. Recently the error pops up periodically, like every 2 weeks something. Each time it pops up the error, I use DIS to run the diagnosis, it shows 'accumulator filling pressure remains constant', then I run the test to see what the problem is, the test completes without problem and the system comes back to normal and works ok. However, the error pops up after around 1-2 weeks and I run the test again, then everything gets back to normal. This has been happening for more than 3 times and I believe it will come back again in 1 or 2 weeks. Does this mean my air supply device (air compressor, usually called) already went bad and it needs to be repaired or replaced? Thanks for help!