"Key not detected", fob not working

[Pipan]

My problem started with my key fobs not being detected by my Hyundai Equus, first every 2-3 days in the first week, and then gradually increased to 80% of times in the next 2 weeks. The keys could lock and unlock by pressing the buttons, but could not automatically unlock, or start the engine. Engine would start when the key fob was in the key holder in the glove box.

During those weeks I did these:

1. changed key fob batteries of all my key fobs. RESULT: did not help
2. removed from my car any instrument or electronic device (such as my other car's key that I had put in center console) that I had put in my car since the issue started. Those devices may (or may not) cause signal interference. RESULT: did not work.
3. took the car to AutoZone and checked the car's battery. The battery was 100% charge.
4. disconnected the car's battery cable (only one of the cables). RESULT: IT WORKED. Both key fobs have been working for 4 days with no problem.

I hope these help.

 

[Pipan]

My problem started with my key fobs not being detected by my Hyundai Equus, first every 2-3 days in the first week, and then gradually increased to 80% of times in the next 2 weeks. The keys could lock and unlock by pressing the buttons, but could not automatically unlock, or start the engine. Engine would start when the key fob was in the key holder in the glove box.

During those weeks I did these:

1. changed key fob batteries of all my key fobs. RESULT: did not help
2. removed from my car any instrument or electronic device (such as my other car's key that I had put in center console) that I had put in my car since the issue started. Those devices may (or may not) cause signal interference. RESULT: did not work.
3. took the car to AutoZone and checked the car's battery. The battery was 100% charge.
4. disconnected the car's battery cable (only one of the cables). RESULT: IT WORKED. Both key fobs have been working for 4 days with no problem.

I hope these help.

 

[G-574174]

Over the last few months, the effectiveness of my key fobs has gotten progressively worse. At this point, I cannot lock or unlock the doors or trunk, and the button on the driver door no longer works to unlock the door when I am standing beside the car.

Also, after I get into the car, I now have to insert the key fob into the slot in the dash in order to get the engine to start, which I never had to do until recently. At this point, I am having to use the emergency key in order to unlock the car.

Has anybody had this issue? Does anybody know if it is likely to be low battery strength in the key fob, or could it be a systemic problem in the car? Thanks!

I’m having the same issue
I put my fob on the passenger seat then it starts

 

[Yasha Deon El]

My problem started with my key fobs not being detected by my Hyundai Equus, first every 2-3 days in the first week, and then gradually increased to 80% of times in the next 2 weeks. The keys could lock and unlock by pressing the buttons, but could not automatically unlock, or start the engine. Engine would start when the key fob was in the key holder in the glove box.

During those weeks I did these:

1. changed key fob batteries of all my key fobs. RESULT: did not help
2. removed from my car any instrument or electronic device (such as my other car's key that I had put in center console) that I had put in my car since the issue started. Those devices may (or may not) cause signal interference. RESULT: did not work.
3. took the car to AutoZone and checked the car's battery. The battery was 100% charge.
4. disconnected the car's battery cable (only one of the cables). RESULT: IT WORKED. Both key fobs have been working for 4 days with no problem.

I hope these help.

Just had this happen to me yesterday with the 2011 Equus. I just replaced the fob battery a few minutes ago, and it didn't work. Now when I get home I'll try the car battery disconnect and see if that helps.

______________________________

 

[Pipan]

My problem started with my key fobs not being detected by my Hyundai Equus, first every 2-3 days in the first week, and then gradually increased to 80% of times in the next 2 weeks. The keys could lock and unlock by pressing the buttons, but could not automatically unlock, or start the engine. Engine would start when the key fob was in the key holder in the glove box.

During those weeks I did these:

1. changed key fob batteries of all my key fobs. RESULT: did not help
2. removed from my car any instrument or electronic device (such as my other car's key that I had put in center console) that I had put in my car since the issue started. Those devices may (or may not) cause signal interference. RESULT: did not work.
3. took the car to AutoZone and checked the car's battery. The battery was 100% charge.
4. disconnected the car's battery cable (only one of the cables). RESULT: IT WORKED. Both key fobs have been working for 4 days with no problem.

I hope these help.

This is an update to my previous posting on 09/04/2019:

The problem returned after a few days, and after a couple of months, the randomness became "permanent". Very annoying. In January 2020 I took the car to the dealership, and after the car being there for 5-6 days and 2-3 hours of diagnostics by them and with the help of non-on-site Hyundai Technical group, they said they found the problem. They said they found a broken piece of key!!! in the key slot in the driver door (It did not happen to me, but maybe to the previous owner). They said removal of that piece fixed the issue. They said they checked the fob battery and also reprogrammed the fob but those had not solved the issue. So, I picked up the car and the key was detected only for about 10 hours, and again the issue returned. Again very frustrating. Need to go back to the dealer again.

 

[Yasha Deon El]

This is an update to my previous posting on 09/04/2019:

The problem resumed after a few days, and after a couple of months, the randomness became "permanent". Very annoying. In January 2020 I took the car to the dealership, and after the car being there for 5-6 days and 2-3 hours of diagnostics by them and with the help of non-on-site Hyundai Technical group, they said they found the problem. They said they found a broken piece of key!!! in the key slot in the driver door (It did not happen to me, but maybe to the previous owner). They said removal of that piece fixed the issue. They said they checked the fob battery and also reprogrammed the fob but those had not solved the issue. So, I picked up the car and the key was detected only for about 10 hours, and again the issue resumed. Again very frustrating. Need to go back to the dealer again.

When I got home I popped the trunk, detached and reattached one of the battery cables, jumped in the driver seat and..................nothing. So I'll have to live with this for a minute until I have the time to play dealership guessing games.. They have years of this happening now with just about all their vehicles having this problem. So you would think they'll know what the problem is as soon as you take it in. But judging by your experience, they're playing the stupid game to get money out of you. When I do go in, I will make it clear to them that this is not some random unknown issue they've never seen before, and I won't except anything other than a complete solution. I get it they may not have the part(s) in stock, and I may have to return, but I'll be ready for their clueless game. The more I look into this, the more I find out it's not new or some one off problem.

 

[Kyser_Soze]

I see some very frustrating issues here and my comment is not related to some of them. My car notified me of a weak battery in my key fob with a message on the speedo display! I took it immediately to Ace Hardware and for the price of the battery they replaced it. I only had 1 fob at that time and didn't want any problems. I now have 2 fobs.

 

[G-969772]

This is an update to my previous posting on 09/04/2019:

The problem returned after a few days, and after a couple of months, the randomness became "permanent". Very annoying. In January 2020 I took the car to the dealership, and after the car being there for 5-6 days and 2-3 hours of diagnostics by them and with the help of non-on-site Hyundai Technical group, they said they found the problem. They said they found a broken piece of key!!! in the key slot in the driver door (It did not happen to me, but maybe to the previous owner). They said removal of that piece fixed the issue. They said they checked the fob battery and also reprogrammed the fob but those had not solved the issue. So, I picked up the car and the key was detected only for about 10 hours, and again the issue returned. Again very frustrating. Need to go back to the dealer again.

2nd Update. After sitting in the dealership for the 2nd time for 18 days, they said they found one of the eight proximity sensors/antennas, which was in the trunk, was faulty. My extended warranty paid for its replacement. Again 6-7 hours after I picked up the car, it stopped working, and the key was not detected again. The dealership had told me that they kept it a couple of more days after replacing the antenna to make sure. I wanted to return int again, but the damn Corona Virus, made me decide keeping the car at home.

______________________________

 

[Yasha Deon El]

Well.....I'm going to say something that like many people, would never do and admit I was a dumb ass! Yep. Well not 100%, more like 60%. I changed the battery in both my fobs and neither one worked. But then after another try at it. I noticed that..........I had the @#$A% battery in upside down!!!. Go ahead.....laugh your ass off. Now once I got the battery in the right way....... it still took a few days of driving for the car to recognize or re-calibrate the fobs. I don't drive far to work so it still didn't work right away. But one day I leaving work decided to push the button and..... what do you know.... we have ignition! Got home turned the car off, and just to make sure it wasn't dumb luck, I started it up again. Went inside and told the wife that it just worked. And no, to the hell no did I mention the batteries being upside down!

 

[EdP]

Well.....I'm going to say something that like many people, would never do and admit I was a dumb ass! Yep. Well not 100%, more like 60%. I changed the battery in both my fobs and neither one worked. But then after another try at it. I noticed that..........I had the @#$A% battery in upside down!!!. Go ahead.....laugh your ass off. Now once I got the battery in the right way....... it still took a few days of driving for the car to recognize or re-calibrate the fobs. I don't drive far to work so it still didn't work right away. But one day I leaving work decided to push the button and..... what do you know.... we have ignition! Got home turned the car off, and just to make sure it wasn't dumb luck, I started it up again. Went inside and told the wife that it just worked. And no, to the hell no did I mention the batteries being upside down!

Maybe you had the battery right but the fob was upside down. Yeah, I bet that was it.

 

[Kraig Wilkinson]

I see some very frustrating issues here and my comment is not related to some of them. My car notified me of a weak battery in my key fob with a message on the speedo display! I took it immediately to Ace Hardware and for the price of the battery they replaced it. I only had 1 fob at that time and didn't want any problems. I now have 2 fobs.

How many Gennys do you see on the road out there in Montana?

 

[Kyser_Soze]

How many Gennys do you see on the road out there in Montana?

I've owned my car for 2 years and live in Missoula. I've seen 4 in town, so they are a bit rare. One of the 4 was a client that came to see me at my job last year! With so few around, what are the odds of 2 owners ending up across a desk from each other? She had a white and I have a black.

______________________________

 

[EdP]

I've owned my car for 2 years and live in Missoula. I've seen 4 in town, so they are a bit rare. One of the 4 was a client that came to see me at my job last year! With so few around, what are the odds of 2 owners ending up across a desk from each other? She had a white and I have a black.

Hmmm, sounds like a gray area.

 

[Kraig Wilkinson]

Hmmm, sounds like a gray area.

Yeah it does!

 

[Kat]

My Genesis key fob took a spin through the washing machine, and after that did not work. After taking it apart and letting it dry, I replaced the battery. It worked for about 5 minutes before dying. I ordered a new fob from a Hyundai dealership. When they tried to program it, not only would it not program, their attempt to program the new one left my other fob not working either. They’ve been trying to figure it out for a couple of days but are perplexed. Any ideas on what might be causing the fob programming problem?

 

[Velasquez23]

Having a similar problem with my 2010 Hyundai Genesis 3.8L V6 , Changed car battery , key fob battery , had the key fob reprogram & got a new key fob , nothing seems to work! , Car still runs however it seems as the car doesn't detect the key fob and my Main issue is that the key wont lock , unlock , open trunk, etc, (Radio wont power off because the key fob wont lock the car ) So i've been unplugging the battery so it won't drain it . If you have any suggestions PLEASE Let me know .

______________________________

 

[weeeezzll]

Well.....I'm going to say something that like many people, would never do and admit I was a dumb ass! Yep. Well not 100%, more like 60%. I changed the battery in both my fobs and neither one worked. But then after another try at it. I noticed that..........I had the @#$A% battery in upside down!!!. Go ahead.....laugh your ass off. Now once I got the battery in the right way....... it still took a few days of driving for the car to recognize or re-calibrate the fobs. I don't drive far to work so it still didn't work right away. But one day I leaving work decided to push the button and..... what do you know.... we have ignition! Got home turned the car off, and just to make sure it wasn't dumb luck, I started it up again. Went inside and told the wife that it just worked. And no, to the hell no did I mention the batteries being upside down!

I for one would just like to thank you for sharing your dumbass-ness. My fob started acting up, working sometimes failing others, then after a few weeks it just stopped. I replaced the battery with one I had on hand, and still nothing. So I went to the store a bought a new set thinking it might have been dead/old/bad. Still nothing. I've opened my fob and removed and inserted my batter dozens of times over the last two weeks hoping that one time it might just magically start working. I was at the point where I had resigned myself to the idea that I would be dropping $500-600 at the dealer to get a new key. I read other post about the battery being inserted wrong but didn't think that applied to me. It wasn't until I read your brave admission that I stopped and thought:

"Hmmmm...maybe I TOO am afflicted with this condition?"

I opened the key fob, and tried flipping the battery over. It felt weird like it didn't go that way, and look backwards compared to most button cell batteries I've seen. I walk outside to the parking lot at my job and hit the button and glory of all glories...IT WORKED!! I feel very conflicted right now. One one hand I'm extremely relieved that my key fob is functioning again, on the other hand I have to come to terms with my newly discovered disability.

 

[G-208173]

I

Over the last few months, the effectiveness of my key fobs has gotten progressively worse. At this point, I cannot lock or unlock the doors or trunk, and the button on the driver door no longer works to unlock the door when I am standing beside the car.

Also, after I get into the car, I now have to insert the key fob into the slot in the dash in order to get the engine to start, which I never had to do until recently. At this point, I am having to use the emergency key in order to unlock the car.

Has anybody had this issue? Does anybody know if it is likely to be low battery strength in the key fob, or could it be a systemic problem in the car? Thanks!

I changed my battery and it still doing the same thing.

 

[weeeezzll]

I

I changed my battery and it still doing the same thing.

Have you tried flipping your new battery over and inserting it the other way? I know it sounds stupid, but...

I for one would just like to thank you for sharing your dumbass-ness. My fob started acting up, working sometimes failing others, then after a few weeks it just stopped. I replaced the battery with one I had on hand, and still nothing. So I went to the store a bought a new set thinking it might have been dead/old/bad. Still nothing. I've opened my fob and removed and inserted my batter dozens of times over the last two weeks hoping that one time it might just magically start working. I was at the point where I had resigned myself to the idea that I would be dropping $500-600 at the dealer to get a new key. I read other post about the battery being inserted wrong but didn't think that applied to me. It wasn't until I read your brave admission that I stopped and thought:

"Hmmmm...maybe I TOO am afflicted with this condition?"

I opened the key fob, and tried flipping the battery over. It felt weird like it didn't go that way, and look backwards compared to most button cell batteries I've seen. I walk outside to the parking lot at my job and hit the button and glory of all glories...IT WORKED!! I feel very conflicted right now. One one hand I'm extremely relieved that my key fob is functioning again, on the other hand I have to come to terms with my newly discovered disability.

 

[G-170896]

Over the last few months, the effectiveness of my key fobs has gotten progressively worse. At this point, I cannot lock or unlock the doors or trunk, and the button on the driver door no longer works to unlock the door when I am standing beside the car.

Also, after I get into the car, I now have to insert the key fob into the slot in the dash in order to get the engine to start, which I never had to do until recently. At this point, I am having to use the emergency key in order to unlock the car.

Has anybody had this issue? Does anybody know if it is likely to be low battery strength in the key fob, or could it be a systemic problem in the car? Thanks!

I have the exact same issue and my keyfob was tested for good battery power and signal. Some forums indicate problem can relate to a faulty bcm - body control module.