Hi. I recently got a second key coded by the dealer. Worked fine for a week. Today it suddenly stopped working. open the car with first key, start car with second key (car does start), stop car, then lock car with second key, now second key works again. But when I lock the car with the first key, no chirp. Lock with second key: blinking and chirp. What could've caused the car to forget the remote/lock/unlock function of this second key? The Battery in it is good.