Recently, the plastic cover of my master key has started to break down. Luckily I have a spare master key, however, when I use this spare key, I can open the door, trunk, and start the car when I insert the key but when I try to use it remotely, it doesn't work. Any ideas what I need to do to make the remote work?

 

You will need to program the wireless door locks. It involves pressing lock/unlock and opening/closing the doors. Search on "programming door locks".