A recent long run about 1500km from Spain to UK generated a fault. The message in photo came up, I was doing average speed of around 80mph air-con on for 20C outside temp around 33C. I had been running at this stage approx 500km and had had only one stop. Yellow warning light came on and on screen warning as per photo. Stopped car opened bonnet no visible signs coolant etc all OK. Left for 15 min restarted car engine light went off and screen warning went. Continued journey a further 800km no problems. Visit a friend f mine who has a dealership ran diagnostics nothing showing! A week later did return journey and on last 2 days of the 4 day trip this happened 4 more times eventually turned air-con off reduced speed a bit and went home. Booked into BMW for diagnosis problem was there was a 3 week delay here in Span for appt, anyway they had it 3 days no fault code showing. MBW/Mini say they have no idea of cause but come cack if it happens again problem is if car cools there will be nothing to see. So today purchased Bimmerlink and an OBD will run permanently going to try car on a long 30km uphill route in Sport Mode with air-con on full to see if I replicate and to see if OBD captures anything. Anyone who has had similar or advice will welcome it many thanks.