Hello, I have the exact same issue as this, I have a 2009 citroen c5 and was just sitting on a hill then I got that message, the car stayed at full height until I finished my journey but the next time I got into to drive the car it was at its lowest setting and will not go up or down, have tried the fuses in the glove box and the one in the engine and they are Ok, only ones I can't get to is the maxi fuses, I can see them but just can't get at them, tried removing the battery to get at them but just cannot find a way to get them out, I'm really hoping that it is just a maxi fuse but I am fearing the worst.