Auto Leveler

Hi, could someone explain the auto leveler, and its function. I had the car jacked up the other day rotating tires and every few minutes something under the hood in front of the master cylinder on the wheel well would start up. I'm guessing this is the auto leveler, right? It also goes on for a minute or two when we garage the car at the end of the day.

Thanks,
hshift

Its just a small air compressor that, when the auto level sensor located under the car signals an uneven car, kicks in to air up the rear air bladders to level the car out.

Its a nice feature, untill something quits working...