Key fobs not working?

Tiny
JAMES CHRIS WILLIS
  • MEMBER
  • 2018 FORD FUSION
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 120,000 MILES
I was installing a new stereo and had a friend messing with a wire that came out of the wire harness, trying to find where it goes. Must have tried the wrong slot cause now my key fobs don't work. Trying to start the car it says no key detected. None of the buttons warm either. It's push button start. Only way it will start is by putting the key in the cup holder, it's some method of starting it if the key fobs dead. It's not dead. Just tried new batteries. Please help.
Tuesday, July 18th, 2023 AT 4:12 PM

6 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Do you know what color the wire was and if it shorted when he tried to attach it?

I attached two pics below. The first one identifies the PATS (passive anti-theft system) components and their locations. Pic 2 is the legend for the parts shown in the picture. Let me know what your friend was closest to when the problem occurred.

Let me know.

Joe

See pics below.
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Wednesday, July 19th, 2023 AT 9:26 PM
Tiny
JAMES CHRIS WILLIS
  • MEMBER
  • 4 POSTS
I am posting a picture of the connector that I'm sure the short is connected with. And a picture of the wire harness that was supposed to connect with. The purple wire came loose from the harness with the pin intact. My friend tried sticking it in holes on the connector that leads into the dash, and it shorted out something. Also note the connector in the dash is the one that goes to the back of my original radio screen. It's a 4-inch sync screen.
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Thursday, July 20th, 2023 AT 9:56 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Here is what we need to do. I looked at the pics, but don't know what he plugged them into. So, we really need to start with scanning the can-bus.

CAN stands for controller area network. Basically, the different modules are tied together via a few wires. This type of scan will retrieve codes regardless of the module storing them. If I had to guess, I would say there is either an issue with the body control module or the PATS.

Here is a link showing how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

If we don't go this route, it will become a guessing game.

Let me know.

Joe
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Friday, July 21st, 2023 AT 7:55 PM
Tiny
JAMES CHRIS WILLIS
  • MEMBER
  • 4 POSTS
I ordered the scanner and it should arrive Sunday. I will follow up when I do the scan.
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Friday, July 21st, 2023 AT 10:00 PM
Tiny
JAMES CHRIS WILLIS
  • MEMBER
  • 4 POSTS
Great news. I traced it back to 2 fuses I had no idea had anything to do with it. Key fobs are back online. Thank you, guys, for the help.
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Monday, July 24th, 2023 AT 5:12 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

That is great news and thanks for the update. I'm glad to know you got it repaired and working again.

Feel free to come back anytime in the future if you have questions.

Take care,

Joe
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Monday, July 24th, 2023 AT 9:40 PM

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