A few weeks back the high pressure sensor on my Audi A3 (2007) burst without warning, releasing all the aircon gas in a whistling stream. Sounded like a kettle for about 20 minutes! Got it fixed at a trusted specialist at a cost exceeding Â£500 (new design sensor including pipes, 4 hours labour as a pain to fit, re-gas etc) - dealer quotes were Â£1K+ and I was three days out of warranty!!! All worked great for a couple of weeks, until without warning the 'econ' light will now not go out and therefore no aircon No dramatic leaking this time though or any other symptom. The car is obviously going back in, but I was wondering if anyone had any informed idea of what it might be? Perhaps another part known to fail? - I believe a low pressure switch is a possibility? Clearly the compressor could be at fault - but I'd rather not think that as my wallet hasn't recovered yet!