So the car has about 68k miles on it, and the key fob has worked well thus far. Recently, I took it apart to clean the plastic (super dirty from human gunk) and change the battery. After I put it back together, the key fob had absolutely no response at all to the car. I could not /start/unlock/lock/open trunk with the remote, the door handle button didn't do anything when I clicked it, and the only way to get the car to start was to hold the fob directly in front of the start button. I had to open it with the manual key as well. All of a sudden (about a week ago), the unlock/lock/open trunk buttons started working out of nowhere, which was awesome, but the door handle, remote start, and start button still didn't work. So about two hours ago, I unplugged the negative terminal on the battery to reset the ECU, and then plugged it back in after about forty-five minutes. All of my HUD settings were reset, but the GPS nav still had my addresses in it for some reason (did I not reset it correctly?). Then, I went to get something to eat, and when coming out of the restaurant, I decided to try the remote start again just in case and it worked. Even after all of that, the door handle buttons still don't work, and the car gives an "incorrect key ID" or sometimes "key not detected" error when trying to start the car without holding the fob directly in front of the start button. Does anyone have any ideas about what would cause this? Did I reset the ECU correctly, and if so, would that have fixed the issue? DO I need to reprogram it (not likely since most things work)? Any help would be greatly appreciated. Thank you in advance!