Question on ride heightin rear

Whats goin on guys, i am new to this board....I have a question on the ride height in the rear..I have a 98 deville and the car seems to be riding a few inches lower than stock( about 2 to 3 inches lower) I was wondering if someone could help me to find out what may be the problem or if someone has had the same issue..Im not sure but i checked to see if there were any error messages and the werent any current so i am pretty lost...Any help would be great.Thank in advance!

Is the compressor working? You should hear it cycle for about 10 seconds after you start the car up.
You could also have a leak in one of the air lines, or the height adjustment arm could be bent.

Thanks for the input. I will check on this and get back to u..