Programming a Key Fob

[canvert]

Have a 2017 V6 Convertible with the standard 5-button key fob. Purchased a used 2018 fob with 5 buttons from eBay. Looks different but I read here the 2018 fobs work with the 2017s.

Went through the programming steps with my 2 existing key fobs and the 3rd key fob.

Usually on the last step I get 2 message boxes:
"Key not detected"
"Key program failure"

Does the old key have to be "unprogrammed" somehow? This is a used key that has never been unprogrammed / deprogrammed as far as I know. Manual says to use a "new unprogrammed" key.

I tried following the steps properly. Does the key need to be any specific orientation?

Perhaps the 2018 fob is not compatible with the 2017.

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[jimmerheck]

I used this thread to purchase and program a third keyfob for my car, the info you need may be in here. When you bought your used keyfob, did you make sure to match the fcc frequencies? I have also read the 18's will work as long as the numbers match...

https://www.mustang6g.com/forums/th...to-buy-replacement-keyfob.84058/#post-2128545

 

[canvert]

Actually the FCC IDs don't match. I think all the 2018 5-button remotes are M3N-A2C931426 (this is the new style)
https://fccid.io/M3N-A2C931426

My 2017 5-button remote is: M3N-A2C31243300 (this is the old style)
https://fccid.io/M3NA2C31243300

In this thread
https://www.mustang6g.com/forums/threads/blasted-key-fob.96675/page-2#post-2202807
...it indicates the 2018 remote works with the previous years if it uses the same frequency. The two above use the same frequency.

Perhaps @Kasavias or @HizliBullet know of a fix since it seems they got the 2018 fob to work in their cars.

 

[jimmerheck]

in case they dont see this thread, you may want to send them private messages to ask for their help.

 

[Cobra Jet]

Are you using a fob that has remote start vs non-remote start? Apparently there is a difference in the fobs.

You may want to review that thread you linked in your 3rd post, because someone was having issues with programming and it was stated that in Step 7 the user should be holding the start/stop button instead of just pushing it and that worked.

 

[Kasavias]

@canvert

Just seeing this thread now. The FCC IDs didn't match for me either, but the frequencies did. That was initially a concern prior to purchasing my 2018 key, but @HizliBullet had shown me a video of his working and I later programmed mine with only a small issue. Like Cobra Jet said, I held the button at the end instead of quickly pushing it and that's what was able to successfully program it. I may have pushed it two or three attempts and then it was successful upon holding it down.

I have no idea what steps are necessary to unprogram/deprogram/unpair a key from a previous car, but if there if there is a process (and I'm sure there is, rather than just programming an already programmed key to a different car) then I guess that could be an issue if it wasn't done properly.

Hopefully it was just a matter of holding the button down, but let us know the status either way so we can help out those that try this in the future!

 

[HizliBullet]

yeah u gotta make sure the frequencies match, theres a website that lets u check that.. plus only the dealer can programme 2018 fobs because the fob molding in the center console doesnt match the new key fob style, so they have to manually programme it..and yes u can use 2 factory fobs plus the new 18 fob together

 

[canvert]

Couldn't get the 2018 fob to work with the 2017. Tried holding the start button at the end but still didn't work.

Pretty much am giving up on it.

 

[p6cl]

Couldn't get the 2018 fob to work with the 2017. Tried holding the start button at the end but still didn't work.

Pretty much am giving up on it.

I have a loaded 2016 Mustang Auto w/ remote start and I was able to program 2 additional keys. My frequency is 902 mhz in all 4 remotes. I have 2 old remotes and 2 new 2018 remotes.

1. Remove the rubber covering from the cupholder. Place the first programmed key in the backup slot at the bottom of the cupholder, then press the ignition switch.
2. Wait 5 seconds and then press the push button ignition switch again.
3. Remove the Intelligent access key.
4. Within 10 seconds, place a second programmed intelligent access key in the backup slot. Press the push button ignition switch.
5. Wait 5 seconds and then press the push button ignition switch again.
6. Remove the Intelligent access key.
7. Place the upprogrammed intelligent access key in the backup slot and press the push button ignition switch.

Programming is now complete. Verify the remote control functions operates and your vehicle starts with he new key.
If programming was not successful, wait 10 seconds and repeat steps 1 through 7.

The main thing with the remotes is that the frequency matches. Remote start is 902mhz normal remotes are 315mhz.

 

[MSMStannyl]

Figured I'd throw my issue out there since it sounds like some of you guys are well versed in this key fob business. As with everyone else, when I purchased my new 15' GT, it came with 2 key fobs. For all these years, I was mainly just using one of them. Recently, I started getting a message that the battery was low and should be replaced. When out and bought the 2 batteries (CR2035's I believe? I can't remember at the moment but they were the correct ones). Popped open the fob, removed the inner piece with the emergency key to get to the batteries, and removed the batteries. Replaced with the new batteries in the weird pattern that's needed (Basically [-|+] [+|-] with the little white flap in between). Closed everything up and....nothing. Could not open the door or start the car. Remote doesn't work at all. Had to tear up my place to find the spare so I could get to work.

My question is, is there any reason that replacing the battery should wipe the remote programming and require the remote to be reprogrammed? I tried putting it into the cupholder slot and it seems to let me start the car which makes me think the programming is still good. It also still recognizes that there are 2 Admin keys so that's good. I'm guessing I either broke something to where the actual transmitter isn't working, or maybe I got a bad batch of batteries.

I'll try another set of batteries but wanted to throw it out there in case anyone had suggestions. Thx

 

[jimmerheck]

Figured I'd throw my issue out there since it sounds like some of you guys are well versed in this key fob business. As with everyone else, when I purchased my new 15' GT, it came with 2 key fobs. For all these years, I was mainly just using one of them. Recently, I started getting a message that the battery was low and should be replaced. When out and bought the 2 batteries (CR2035's I believe? I can't remember at the moment but they were the correct ones). Popped open the fob, removed the inner piece with the emergency key to get to the batteries, and removed the batteries. Replaced with the new batteries in the weird pattern that's needed (Basically [-|+] [+|-] with the little white flap in between). Closed everything up and....nothing. Could not open the door or start the car. Remote doesn't work at all. Had to tear up my place to find the spare so I could get to work.

My question is, is there any reason that replacing the battery should wipe the remote programming and require the remote to be reprogrammed? I tried putting it into the cupholder slot and it seems to let me start the car which makes me think the programming is still good. It also still recognizes that there are 2 Admin keys so that's good. I'm guessing I either broke something to where the actual transmitter isn't working, or maybe I got a bad batch of batteries.

I'll try another set of batteries but wanted to throw it out there in case anyone had suggestions. Thx

I replaced the batteries in my 6sp manual keyfob a few months ago and it worked perfectly when I was done, there were no issues with mine. Dead or low batteries? Wrong installation? Since you seem pretty sure on the battery installation, maybe low or dead batteries.

 

[canvert]

Removing the batteries has no effect on the memory from what I have seen with these key fobs.

However, I decided to give the programming another try today when I saw this thread and it finally worked after a number of tries.

Not sure why it worked this time but followed the steps exactly as outlined above with the following changes:

1) Remove any key rings from the fobs
2) For the existing old style 2017 keys, they were inserted with the key hook facing down and buttons facing the back of the car
3) For the new 2018 key to be programmed, it was inserted key hook facing up and buttons facing the back of the car
4) When programming the 2018 key, I pressed it down very firm in the slot (not sure if that made a difference)

Was amazed when it finally worked.

So confirmed a few things:

1) The 2018 5-button remote (M3N-A2C931426) works with the 2017 5 button remote (M3N-A2C31243300). Even though they have a different FCC-ID they both have the same frequency
2) Seems like the direction the key is facing (key hook up/down) makes a difference. Try different combinations but the buttons should always be facing back
3) A used key can be reprogrammed to another car. No need for an unprogrammed key
4) Make sure you hold the start/stop down on the last step not just click it like mentioned above
5) If you are getting "Key not detected" or "Key program failure", you are on the right track. Just need to try different combinations with the key orientation and perhaps hold the key that needs to be programmed firmly in the slot.

 

[Fredboy]

I made a quick video showing how to program the key.

 

[Blade007]

Hi Guys,
Merry Christmas to you all. I just got the new fob but I can't seem to program it. I tried the steps above and what was done in the video and no dice. Not even an error message. What i did notice however is that there is now 3 keys listed on the car. I believe there were 2 prior and i only have 2
The car is a base 2017 mustang

This the pictures of the keyfob in case I may have the wrong one.
Any help would be greatly appreciated

Thanks

 

[p6cl]

The remote is the wrong one for your car from what I can tell. You have a remote for a Premium car with Remote Start. That is on the 902mhz (I think from memory) your car has I believe 433mhz for the remote or 315mhz. Unless your base car has remote start for some reason that I do not realize.

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