Not had the opportunity to drive the Z recently, went to give it a run out earlier and the battery was flat. Tried to start it with a battery pack, but failed. Finally got it started using Jump leads. Once started it instantly threw up the transmission fault - please drive moderately message on the idrive screen. The gearbox would not change between any other year than P and N. Didn’t have enough power to turn off car and restart under it own steam. Any thoughts on what this good be?