it could be the doors are open?
Slabs ECU talks to the body control ECU before making any adjustments to the suspension. make sure you're not testing it with the door's open
hi
try if the open the door wait and listen for the air pump in the engine compartment if you hear it close the door if it dosent raise you could have a leak try soap and water on the air bags and pipes to check. with the doors closed .
the other solution chage it to springs a simple job and can be cheaper than repalcing the air system.
Ive found the problem, Ive replaced the back load sensor, it was broken, got it booked in for friday to have the computer reset it all as its still not 100% happy..
I have recently had some air suspension woes and i took it to an after market specialist to see if the computer needed re-setting and he told me not to waste my money as it will sort itself out. I have replaced a sensor that broke and it did sort itself out. if one broke check that the arm on the other side is free to move, undo bolt on bottom of arm and check it is lubed up or it will sieze and then cause the arm to snap.