My 89 535i is a third car and a new purchase. I just picked up a second key from the dealer yesterday and on the way home, lost the original key (smart, huh?). The new key opens the doors and turns dash lights on but does not start the car. I don't know if the battery is dead (wouldn't jump) or if the new key is not working. Would the key open doors and turn dash lights on if it wasn't the correct code?? Any other thoughts/suggestions??