my epc light has come on a few times in the last two weeks. Nothing seemed to be affected at first, untill my battery went dead and i had to change it. after the battery change car would not start for an hour. tech said probably security issue and i should leave my key in ignition to re recoginize. this did work for about 30 minutes. went inside and came back out car started hard had to crank for awhile again three times popped a epc again and then check engine any ideas would be greatly appreciated