My wife was out cleaning her tb today, Left the key on for an hour while cleaning. After shes done she goes to start it and it wont. She puts the battery charger on it for 20min and it starts right up. Check engine light came on though. I had her drive to adavance thinking its the battery and get code p1682. I did research and it said ignition switch. How hard is it too change? Could it still be the battery. I came home and now the check engine lights not on. Could the battery just have died and needed recharged? Its got nav, rear dvd, bose, and power everything if that helps.