2003 MZB S430

I noticed that the air system is engaging and lowering the left rear suspension to the bottom. It happens after I shut off the car. When I get in to start it,the light says car too low aand I have refill the air andpush the up button for suspension

 

The system is not lowering the left rear suspension. The problem is virtually certain to be a leak in the left rear Airmatic strut (most likely) or a leak in the air line to the strut (much less likely) or a faulty valve for that line in the system valve block (very unlikely). You shouldn't have to do anything to be able to drive the car except to crank the car and let the Airmatic compressor refill the strut. You do need to replace the strut.