I went for a drive to shop and on return removed shopping and left the Mx in the drive, expecting to take it out again. About 5 hours later, not having gone out again, went to park it and found the car totally dead. Battery voltage was 3.5 v, and every sign of life gone.
Put it on charge, and about an hour later, the battery voltage was 12v, so tried to start it but failed, but got a bit of a kick from the starter. Left it a bit longer and battery was at 12.5v and car started. So took it for a 5 km drive and everything was back to normal - wll sort of - car drove perfectly, but radio was reset, mpg was at zero, and fuel gauge was very low compared with the 50% it should be at. After drive, fuel was about right, mpg had got to 30 or so, when before it was at 47mpg.
Any idea why this would happen? I cannot think of anything other than I may have left the ignition on, but I do not think I did.
Do I need to do anything to get the ECU to recalibrate or does it do that itself? Will it just work everything out itself?