Originally Posted by mart_dev

Assuming you've had someone clear the fault code or you've done it yourself and it reappears, it therefore most likely (although not a guarantee) there is a mechanical/electrical fault with one of the ride height sensors. You could manipulate the sensors manually to see if they send a signal to the control ECU to lower/raise the body. I have done this in the past after swapping out my springs...definitely not a scientifically sound practice but it worked for me. Vehicle in the fully raised position (engine off but car still "awake" - wriggle under the vehicle and gentle manipulate one of the sensor arms...if you've manipulated it in the correct direction for lowering, it will let some air out, and vice versa for raising.

Hope it answers some questions. Like I said, not a proper way to do things so please do it carefully.