What are the possibilities of what could be wrong?
The air suspension system is malfunctioning. You may have a leak in an air bag or the pressure sensor(s) are going bad. You could have a leaking air line. Do you mean by, light going off that th light has been on the whole time and is now turning off? Or do you mean that the light is now coming on?
In all likelyhood, it is your 'air shocks'. Caddys have a system by where air is pumped into either a shock or a kind of 'air bag' to help give it that smooth ride. When either the pump, the sensor or the bag starts to have problems, it will cause this sensor to go off. No easy fix for an amatuer on this problem, these things are a pain to work on. Just take it to a shop and have them look at it. And, although I usually don't suggest this, you may want to consider a dealer. Alot of times, smaller shops don't have the equipment to work on something like this. The dealer will have a diagnostic computer that will help tell them exactly what part of your air suspension is failing. Good luck.