Disco2 SLS drama

I changed the airbags on mine, compressor ring and dessicant, and ride height sensors. I guess the compressor was already knackered because after a few months it stopped working. I put springs on and notified the insurance who made a nominal charge. I haven't looked back since and never have to worry about it any more. I can't say I notice much difference apart from no hissing when parking and consistent ride height.

Here are some notes about the air suspension system. It's a good system and with the exception of replacing the air bags I've had no problems at all. New users often find themselves trying to over-analyse SLS problems and that can really make your brain hurt!
The compressor motor does run in short bursts to keep the heat down, it's a relatively small motor with a big job to do. There could be some "compressor duty cycle exceeded" codes logged in the SLABS ECU which might need to be cleared. It's unlikely that a generic code reader will even communicate with this ECU. Use a specific code reader such as Nanocom, Hawkeye or Lynx for DIY or Testbook at the main dealer.

https://www.landyzone.co.uk/land-rover/disco-ii-air-suspension-–-the-definitive-guide.171995/#post-3987603

I dont want to ruin a man's work who took the time to make a guide cos it's something to be respected but unfortunately that guide is full of let's say omissions to not say mistakes, my advice is that if somebody really want to know about the system to read the workshop manual or if deeper knowledge about the management is needed it can be found in WABCO documents but the description/operation and repairs are well covered in RAVE.

about the OP's issue as long as the warning light is on thereshould be a relevant fault code stored(nanocom can miss some while hawkeye is accurate)... though if the compressor kicks in and the valves are not opening thee might be a wiring issue on the valve's command cos the compressor os not supposed to start without at least one air supply valve opens

the best is to use a dedicated tester as Brian said and run circuit tests with it for each valve and see sensor live readings, then the mistery will be revealed

Thanks gents! Much appreciated. I have a mate with a tester so we'll have a go at diagnostics tomorrow. Will let you know how we got on.

Good day all. It's with a fair amount of shame that I have to inform you that it was me who was at fault here. We hooked up a tester and we tested if the valves on the air valve block opened and they did indeed. Because I replaced the piston ring on the piston of the compressor, we connected a pressure gauge (manometer) to the discharge side of the compressor with the purpose to test the compressor. We applied 12V from a spare battery to the plug of the compressor after we unplugged it from the system. The compressor ran on its own but the discharge pressure did not exceed 4 bars. Not enough to fully inflate the bladders. We opened up the compressor again, only to find that the new piston ring was incorrectly installed. We tested a spare compresor the same way and within seconds, the pressure went up to 9 bars. So there you have it....my error. RTFM! Anyhow, another new piston ring installed and problem solved. I purchased the new piston ring from www.bagpipingandy.co.uk It comes with an installation guide but he also shows installation videos on youtube. Cheers for everyone's response to this thread and the sound advise!