"Key not detected", fob not working

[mtrot]

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!

 

[rminor]

Have you tried changing the battery? Do you have more than one fob?

 

[mtrot]

Have you tried changing the battery? Do you have more than one fob?

Thanks. No, haven't changed the battery yet, wasn't sure how to do that. But I do have another fob, which has sat in a cabinet since I got the car, and it does not work either. But I guess both batteries could be bad now.

 

[Mark_888]

Go to the camera department of any store like Walmart and get a couple of 2032 batteries. I recently bought some Energizer Battery CR2032 Lithium 3v batteries in a 2-pack for my key fobs. Make sure to peel off any plastic film covering the battery before inserting into the key fob.

Pry open the key fob with a small bladed screwdriver and it will open so you can replace the battery.

 

[xcarrion777]

Its most likely the battery. Happened to me on Saturday and just needed a jump on the battery.

 

[andriver]

I had the same problem. I took the car battery to be checked. It had a low charge so I replaced it. The next morning the same thing. I took it to the dealership and they found it was the battery fob. They replaced the battery for free.

 

[radicaltimes]

A low or bad car battery will not cause the message FOB not detected. Only a bad key Fob or bad Key Fob battery will cause it. One of my Fobs batteries lasted over 5 years and the other only last around 3 years.

 

[xcarrion777]

A dead car battery won't work though. That's what happened to me. Got a jump, let it run for 20 minutes, and I was back in business.

 

[mtrot]

Went to Batteries Plus and had them test the batteries from my fobs. One showed to be low and they said the other was "hot". They also had a device that can test the signal being sent out by the fob. Neither fob was sending out a strong signal. Long story short, I bought two new batteries and both fobs work great now. Thanks for the replies.

 

[KMacCoy]

I replaced the key battery on both keys and I'm still having this issue. It happened to me while I let the car sit over a long weekend. The temperature just dropped here so I wonder if that had something to do with the proximity system going haywire?

______________________________

Help support this site so it can continue supporting you!

 

[mtrot]

A bit of info here that may or may not be helpful to others regarding these Hyundai key fobs. In the process of fooling with my key fobs, I've found that their batteries need to be putting out more than the nominal rating of 3 volts. For example, I used a volt meter to check one of the batteries that would not make the key fob work and it was actually putting out 2.9 or 3 volts. So I measured a new battery and it showed 3.2 volts output and the key fob worked with that battery. So, I would say if you are having problems with key fobs, check the actual voltage of the batteries.

 

[GarnetTy1473]

It actually has more to do with the voltage of the battery while it's under a load. New key fob batteries run 3.1-3.2 volts, and drop to around 2.8 - 2.9 volts when under a load. The fobs typically work without issue until they get down to about 2.5-2.6 volts under a load. Then you will start to notice they are getting weak. I have seen plenty of batteries test at 2.9 volts without a load, and drop well below 2 volts under a load. I had one last week testing somewhere around 2.7 volts, but under a load it dropped to 0.6. The dealership also has the tools to test the batteries as well. I keep them at my front counter because I sell several key fob batteries a day.

 

[g_689982]

So my car won’t register that my key is in my car. I’ve replaced the battery twice and it still won’t work. I can lock and unlock my car but the car just won’t start.

 

[G-443206]

I’m having the same issues my key fob will not register to my car and i change the battery in the key fob 3 times but my car does start up without me inserting my key fob, I just can’t lock or unlock my car with my key fob. Does anybody know what i should do?

 

[G-477883]

Anyone come up with a solution

 

[G-306303]

Have you tried changing the battery? Do you have more than one fob?

yes

 

[rolanddarby]

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!

$75, 000 and i am having the same problem with the gs90

 

[EdP]

$75, 000 and i am having the same problem with the gs90

Reading this thread, looks like most of the problems were battery related. Seems no one took it to the dealer for a resolution so if a battery change does not fix it, see the dealer.

You probably already know if it is the battery you can start the car by holding the fob to the "Start" button.

 

[Mcc]

$75, 000 and i am having the same problem with the gs90

What year is your G90 and when did you last change the battery.

 

[G-70462]

Reading this thread, looks like most of the problems were battery related. Seems no one took it to the dealer for a resolution so if a battery change does not fix it, see the dealer.

You probably already know if it is the battery you can start the car by holding the fob to the "Start" button.
[/QUOT