Key Not Detected - 2015 Ford Fiesta SE

Hello all. I need some help because I am close to the point of selling this car to an auction place just to be rid of it.

2015 Ford Fiesta SE Sedan. 59k miles.
Purchased used in 2016 with roughly 28k miles. 2nd Owner. No remaining warranty.
Mods: 10" Rockford Fosgate sub. Backup Camera on rear view mirror. <- both installed in 2016.
My wife is the primary driver.

Problem: Key Not Detected. Intermittent Issue causing the vehicle to not start.
First Noticed: November 2018
Frequency: Was once per month, now roughly every three days.
Duration: 90 seconds to 12 hours.
Attempted Fixes: New Car Battery, New Key FOB Batteries, New Key.
Trips to Ford Dealer: Two
Total Number of Days Car at Dealer: 15

Long Story:
Back in November of last year, my wife told me she had trouble starting her car. Note we live in middle Georgia. So November means 50 degrees and no snow. We swapped cars for a few days and I had no issues with her Fiesta. I thought maybe it was a fluke or operator error. In December she had the same problem, and told me it kept saying key not detected. Eventually it started and she drove home. I looked at the car and saw the battery was 4 years old. So I replaced the battery and thought “problem solved.”

Well the problem didn’t stay solved, and around Christmas time my wife stopped for gas and was stuck for about an hour while the car wouldn’t start. She had both keys with her and neither would start the car. She eventually drove it home and it worked fine. Since basically all of google believes this problem to be key fob batteries, I replaced the batteries in both key Fobs. To prove a point, I also took the batteries out of both key Fobs, started the car, drove to the grocery store, bought groceries, drove the car home, put the key Fob batteries back in. This car does not need a battery in the key fob to work. But… new batteries… no difference. Yay.

I believe we made it through January with no issue. So I was starting to think maybe messing with the keys had knocked something back into place or whatnot.

February was maybe one time for about 15 minutes the car did not work.

March was the first time I ever saw the problem myself - after coming to my wife’s “rescue” when she was stuck picking up dinner, I drove her car home. Then it failed to start over and over in the garage with Key not Detected on the screen. I ended up going to bed without figuring it out. The next morning the car worked great. I drove the car as my daily driver for two weeks with no issue. By this time I thought maybe it was a fault in the anti-theft system.

In April the frequency picked up, maybe once a week the car would say “key not detected.” However, it normally would only take about two minutes of trying before the car would start and work fine.

Which brings us to one night in May (current month) where the car wouldn’t start. I drove to my wife’s work place and together we spent about two hours with it that evening. We gave up and “abaondoed” the car at her workplace. The next morning I got out there around 0430 thinking I’d have the car towed that day to Ford. But it started right up. I drove it to Ford later that day. They ended up keeping it five days and telling me one of the two keys had an intermittent wiring fault. I paid $340ish for a new key and I was highly skeptical that was actually going to fix the problem. The Ford rep assured me the problem would be solved.

I paid and drove the car out of the Ford repair shop on a Tuesday. Wednesday and Thursday I drove it to work and back with no issue. However, when leaving work on Friday - Key Not Detected. And I was using the new key the dealership had made. About five minutes later the car was able to start and I dropped it back off at the dealership. That was May 10, 2019. It’s now May 19, 2019… no word on the car. I’ll checkin first thing tomorrow morning.

However, what could this possibly be? The dealership appeared stumped when I dropped the car back off. I’m told that the Key Not Detected message is normally for a push button start car and is normally caused by a low or dead battery in the key fob. That’s not the case here. This car uses a physical key that you insert into the ignition.

What we have done:
New Car Battery
New Key Fob Batteries
New Key (Ford Dealer)
System Reset (Ford Dealer)
Cell Phones - it should be noted that this happens with phones around and without phones around. I do not believe cell phone interference is a problem here. When I used the car I would keep my cell phone in a completely separate pocket than the car keys.
Engine codes - none.
Computer codes - none.

Ideas that have been tossed around but not acted on:
Replace Ignition Switch - maybe it has a sensor that recognizes keys?
Replace Anti-theft System - I’m not sure what that would even entail.
Have the car stereo place uninstall the subwoofer and backup camera - maybe one of those is causing a fault now? Seems unlikely as they have been there for 3+ years, but maybe?
Dump the car and get a new one - really don’t want to do that.

Has anyone actually had this problem and found a solution? Thank you.

I have an older thread on the Fiesta Faction site. However, I don’t think that site generates as much traffic in terms of views.



Obviously, this car should go back to the dealer because one day it will leave you stranded.Did Elvis work on your car? Look at the tech name.

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Sidenote - the problem occurs with the car doors unlocked, locked, driver door open and driver door closed. None of that seems to make any difference. Day vs. night. Hot vs. cold. Humid vs. Dry. Just used it vs. Been sitting for X hours. None of that seems to make a difference either.

Yes, the car has been with the dealer since 5/10/19.

Yes, Elvis. I’m not sure if that is really his name or if it’s just a nickname they use for him there.

I would suspect a bad ignition switch.I suppose they checked it?

That’s what I’m thinking too. I figure something within the ignition switch must recognize the key - like a sensor or something. My guess is there is an intermittent fault in whatever that part of the assembly is called.

There is a post above dealing with the same subject.Its an older post but someone with a Ford Fiesta had the same problem you have.

“No Key Detected”

Thanks. That’s a year+ old thread that lead me to this forum. I originally posted on there without realizing how old the conversation was already. My hope was that the original poster would come back and explain what they ended up doing with their car.

And yes their problem (although with a 2013 Ford Escape) does sound exactly like the same thing wrong with our 2015 Ford Fiesta. I just wish I knew what they ended up doing to solve it.

The dealer needs to refund you for the key they made for you.

"one of the two keys had an intermittent wiring fault"

Yeah, no. Keys don’t have wires. Plus, you are having the same problem with both keys. Time for a different dealer and/or bumping this up Ford’s corporate chain.

Yeah. It sounded kind of hookey and cost me $340. But the “bad” key was replaced.

Going to a new dealer adds another $180 fee. So it is currently back at the same place that replaced the key.

It seems the security system is working overtime, doing its job so well it is preventing you from using your own car. This problem isn’t an uncommon thing reported here. Not just on Fiesta, many makes and models. The forum search feature may turn up something that might help, upper right on this page.

The problem the Ford techs are having is the security system is purposely designed to be difficult to figure out. If it was easy to figure out, it would be easy for a thief to steal your car. It seems like you have only two alternatives

  • Continue to take it back to the dealer until they finally resolve the problem. They should have whatever equipment is required to do this. But it might take getting their most experienced tech working the job, or even getting a specialist tech involved, from the manufacturer. It might help to mention you’d like to continue to be a Ford customer, and thinking about buying another Ford soon, but are now growing frustrated. Social engineering.

  • Ask the dealer or another shop – an auto-electrics specialist maybe – if there’s a way to defeat the security system entirely, so you car works like my older Corolla; i.e. if the key physically fits and turns the ignition switch, everything works. This might be as simple as installing a replacement ignition switch that doesn’t involve any fancy security electronics.

If I had this problem myself first thing I’d do is a simple diy’er battery and alternator check. Before first start of the day the battery should measure about 12.6 volts. Immediately after starting the engine it should measure 13.5-15.5 volts.

Yes thank you. The dealership mechanic did do the voltage checks and all was okay. I would very much like to have no security system in the car. It’s not like someone is going to want to steal a little red fiesta and if they do that’s what comprehensive coverage is for. I will ask the dealer if that is possible. It may require being at a non ford place. I want to keep the car but I also want it to be reliable.

In speaking of another car, I am planning on getting either a fusion or MKZ for myself. I have had a ford since 2002.

As far as forum searches, I have found zilch (here and elsewhere) that helps for a solution. There is one other thread on here with the exact same problem but it was left without a resolution. Everything else is about push button starts with solutions of replacing fob batteries and/or using some slot by the cup holder.

It’s a little comical because the other thread on here went through that same discussion. I have been google searching this for seven months.

Well we did get somewhere today. The Ford Dealership replaced the “transponder” that recognizes the key on the car side. That’s probably the right fix. They didn’t charge for it either - so the key money probably about evens out.

However, they did break the driver’s side door handle - interior handle that you pull on to close the door. So after just about making a big scene, they agreed to fix that at no cost to me. The sad thing is it will be maybe 5 or 6 days before they have the part.

That’s funny. It’s the inside handle though. I’ll have to get a picture. Highly annoying and definitely not like that when I dropped it off 10 days ago.

Also of note… my concept of me “making a scene” is probably the same as someone else “having a conversation”. I was really, really upset though.