2tc I'm in the exact same boat (2015 though). Got a 3rd remote off ebay (trunk logo vs tailgate) but supposedly compatible. I tried the mustang instructions Start\Stop > 5 secs > Start\Stop... buttons up, buttons down, but the third remote won't program. Hoping we can get it figured out. Just thought I'd let you know you're not alone.

 

So two with trunk remotes can't get them to work,, mine is a tailgate and worked.. Smart trucks we have..

 

Any way to reset/zero out a preprogrammed remote, maybe thats my issue.
Or maybe its not compatible after all. Has anyone successfully added a eBay remote that doesn't show a tailgate but has a trunk logo. For $40- I can't imagine you got a tailgate logo given my searches, the ford part numbers seem to overlap regardless.
There're two styles of 5 button remote one that is linear with all 5 buttons in a row and one that has the two buttons at top open/close thats mine,

 

I paid $60.00 for mine.

 

I went in and had a buddy at a Ford dealership programme my 3rd fob. it was quick and no fuss but he told me it required laptop hook up on this years model. Is that Because of SYNC3, is that because thats what they do at the dealership, or is it because the key fob had a "open trunk logo" vs "open tailgate logo"
Don't know? Bottom line it can be done.
Anyone had success with the "at home" programming of a 2016/Sync3 3rd Keyfob.

Another trick you might like, I discovered - wrap the fob in tinfoil/silver foil and hide it away inside the truck or rear bed and its not found by the system. Now I truly have a spare on board.

Thanks
Tony

 

This is an old thread but I have something important to add. I have a 2016 F150 with sync-3. Bought a used remote for a Focus off eBay (seller said it would work). Used the procedure in the manual to program and failed every time. Used the procedure above and success the first time. The only difference seems to be "wait between 3 and 10 seconds" vs. "wait five seconds."

LOL: when I push the little trunk open button, the tailgate opens. It must know I don't have a trunk.

 

Great to know. Almost tempted to buy a fourth and try again! I think it's the sensation of not wanting to be beaten by the Ford equivalent of "Simon Says"! But I would need to try it soon as summer is coming and can't risk another session inside the truck with windows up engine off frustratingly pushing remote buttons in 90 degree heat.

I do like the Fob with the Silver Mustang on the back and you can order/buy one on eBay without the 2 door 4 wheel additional hardware that Ford usually provides with it
In addition with that model when appropriately configured the trunk logo can open your horse stall door.......

Cheers
Tony

 

I didn't even notice what logo my fob has, maybe a four-door sedan (whee!). When it works, the entire thing takes less than a minute. After all the failed attempts I was shocked when the lights flashed and the door locks cycled.

 

All be damned...Thanks Shovel-ready!! I tried it again and sped up the procedure this time and it worked like a charm.

Here's what I did...
1. I put a small piece of masking tape on the two programmed keys so I knew which keys were which and put all three by the shift lever for easy identification and accessibility.
2. I placed the first programmed key in the backup position
3. With left hand, Press Start\Stop button
4. Counted to three maybe four seconds (one one thousand, two one thousand, three one thousand)
5. With left hand, pressed Start\Stop button
6. With right hand, swapped first programmed key with second programmed key (quickly)
7. With left hand, pressed Press Start\Stop button
8. Counted the three maybe four seconds (one one thousand, two one thousand, three one thousand)
9. With right hand, swapped second programmed key with the un-programmed key (quickly)
10. With left hand, pressed Start\Stop button
11. Door locks cycled and dashboard light up and dashboard counsel stated “Key Programming Successful”

I put both factory keys in the house and tested the new key on door locks, tailgate release and remote start and it works just like the factory keys.

I hope the slightly modified procedure will work for others! Thanks again Shovel-ready!

 

I can confirm with a 2016 Lariat and a key fob off of Ebay with the trunk icon and the speeded up process that it works. Just count 3 seconds every place it tells you to count.

I did not get a screen confirmation that the process completed successfully. All that happened was the door locks cycled.

All functions work, doors lock and unlock, gate lowers (still won't go up though) and the remote start works. Didn't check the panic button, that's for those not carrying a 45 or larger.