Smartkey wont turn from 0 position while in ignition. FOB and spare FOB light up when I press unlock button but vehicle doesn't respond. Vehicle still has power for some functions (moving seats, hazard lights, interior lighting) but these work without the key in the ignition. Have changed battery but did not fix the problem. Problem occurred after attempting to start the vehicle in extremely cold weather with a completely dead battery. Have tried wiping off debris from inside ignition. Is it possible that the dead battery somehow erased my vehicle's memory of the key? Next step will be to change the fuses? Any ideas what the cause could be? Which fuses to change? If that doesn't work what other alternatives are there?