My rangie has been laid up for a time and was down on the stops having been left gathering dust.
When I fired it up and reset the windows etc I took it round the block but the suspension refused to budge.
A check on the diagnostics box showed both offside sensors out of limits.
The compressor was persuaded into life but it still failed to respond.
I gave up and ordered a set of airline over ride valves and started pricing height sensors; then had a little brainwave.
Trolley jack under offside sill, jacked up untill both wheels were hanging free. Then fired up the engine, wherupon the nearside rose to meet the height of the offside on the jack and when I dropped the jack the offside pumped up to match.
This may not be an original idea but it certainly solved the sensor issues.