I had the same probelm a while back... you may want to check my previous threads... there is some information.. couple of things to consider... check the fuses in the back trunk on the rt. hand side... there are two that are related to Air Suspension... 30 and a 7.... if the fuses haven't been blown up, then there could be a reprogaming issue, is that is not the case, then the self leveling equipment underneath your spare tire isn't working properly, if that is the case, then a new one is about $700......... check the fuses first, that is cheapest route and in most cases the cause..