My system information document says that nominal pressure at the front springs at normal ride height at curb weight is about 8.5 bar, or about 125 psi. That is not what they fill at though, during normal lifting, you usually see around 1000 kpa in the gallery, which is around 150 psi. You should be able to easily stop the flow with your finger.
You should be able to hear the compressor running, but it not running could be both the fault, or a result of a fault that is shutting the system down.
I would suggest starting the truck, and leaving the door open, this will force the compressor to fill the reservoir if it can. After about 5 minutes, shut the car off, still with the door open, let it sit for a good 10-15 minutes, then repeat. After the second 5 minutes, close the door and see if the truck can raise then, it should be using mostly reservoir pressure that you should have just built up.
You should be able to hear the compressor running, but it not running could be both the fault, or a result of a fault that is shutting the system down.
I would suggest starting the truck, and leaving the door open, this will force the compressor to fill the reservoir if it can. After about 5 minutes, shut the car off, still with the door open, let it sit for a good 10-15 minutes, then repeat. After the second 5 minutes, close the door and see if the truck can raise then, it should be using mostly reservoir pressure that you should have just built up.