I've realised my air conditioning is not working and only blows non-cooled air. I thought it maybe just needed re-gassed but unfortunately the valve reading is showing as very high when I attached a gauge (so I obviously did not attempt to add any coolant myself). I've tried the ACC diagnostic but this is showing zero error messages. Can anyone suggest some tips for action I can take myself in order to try to fix this or at least work out what the issue is? I realise I may need to take it along to a professional air-con place to get work done but I'd rather try to fix it myself if possible. Many thanks!