Hi everyone

I suddenly got this error message the other day when leaving work for home.
The car is sitting at normal height, but I cannot change heights manually. The light on the height control knob is on. The car does alter height automatically, as I found when I was parked on a slope the other day.
The diagnostic says 1. Reservoir pressure sensor fault 2. Reservoir pressure sensor supply fault.
When I try to clear the fault, it goes for about a second and then reappears.
Is this a case of a new reservoir sensor?
2003 TD6 Vogue