Sdc trailer lift axle

Been using a 2014 sdc trailer and was told it had automatic lift on 1st axle when running empty,up to now I’ve not seen the wheels leave the floor is there a valve somewhere to make it operational thanks

The lift button is on the o.s there’s also an override button further up on same side ,I’ve not been able to get mine to lift as of yet but I think I’ve a value problem .

I have a 2014 with auto lift. It works fine, but if you have an ABS fault then it seems to stay down. It has no manual control or override device. If you are in a tight spot and you want it to stay down then you need to pull the ABS lead off.
Mine also has a failsafe handbrake. When the air has been down or when you’ve had the red line off, you have to push the red button in manually before the trailer will move.