Hello, I am quite new to the forum and to being an owner of a 12 focus sedan sel. Even though I am new I still have something to offer this sight pertaining to your alarm system. Just a little background on the car before i get to the topic, i bought it used from a rental facility with 50208 miles on it. I dont care id it used to be a rental or npt because first off its my labor and sweat paying for the car and second it was with a 75000 mile bumper to bimper warranty from the rental company so it is fully warrantied for 3 years or 125208 miles (i had the sales person go into great deal of what all the warranty covers) now with it being a rental it only came with 2 keys, 1 with the 4 buttons on the key and a plain jane style valet key. So now getting back on topic this is what i dis so i can have more than just one remote for my focus.
First enter your focus and shut the door, make sure you turn your lights and radio off so you can clearly hear an audible beep the car gives off.
Next insert your key ( make sure its not a my key with the restrictions on it), tthen cycle to on (ii) and off 4 times making sure you end the cycle in off position.
Next, if done correctly you will hear an audible beep and an explanation marker lamp will come on. Now you are ready to press the buttons on the key fob(s) you want to program to the car. You just have to press one button per key fob and it doesn't matter which.
Note: once you hear the beep and see the explanation mark you have 10 seconds to program the remotes you want. If you take longer than 10 seconds you will have to start over.
Note: I know for sure my 12 model will hold up to 8 remotes and I also did the same thing to my wife's 2000 Taurus but it only holds up to 4 remotes.
I have programmed my factory key to work on my focus and on my wife's Taurus along with 3 other key fobs for both cars. Yea you can program one remote for 2 cars but if both cars are in distance to the remote it will activate the function you pressed on both cars. Which is funny at first bit annoying after a day. Lol
If any one wants I can post a how to video and also include both cars to show the alarm activating simultaniously on both cars or both of the trunks opening.