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Discussion Starter #1
Happy new year to all!

I've been getting this "key fob not detected" message for about a month now - more frequently recently. It seems to happen now more often as soon as I shut the car off. I've read other threads where some say it's the battery in the key fob and others say the battery has nothing to do with it. I bought the car used and only have one key. I've hit the unlock button multiple times as suggested,but this does not resolve it.

Any comments/suggested fix would be appreciated. I'd like to avoid trip to dealer of possible...

Thanks,
John


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Not sure about yours but mine did it and I replaced the battery no problem since.
 

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Just replace the battery and see if that works.
 

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Do you have another FOB? Had the same problem, "Key FOB Not Detected", with one. Changed the battery and got the dealer to look at FOB which was determined to have failed. The FOB was not covered by warranty however the dealer sold me a replacement for a little over $100.00.
 

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Like others have said, first try replacing the battery. If that doesn't work, the dealer may have to do a re-flash. I encountered this problem when I first bought my 2009, and the re-flash corrected it.

Here are the easy steps to replace the keyfob battery:

1. Slide the button and remove the metal "emergency
key."

2. Use the blade of the key (or small flat screwdriver blade) at that end to carefully pry the two fob halves apart (they have snap tabs) by working around the both sides to separate top and bottom halves.

3. Remove the old battery and replace it with a single disc battery- IIRC a
CR2032 (or equiv.). Note: Hold the battery around the edge to avoid contamination.

4. Line the cover back up and snap the perimeters all around.

5. Re-insert the blade key until it clicks back into place.

(Note: Re-programming is not necessary).
 

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SRT-8
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Discussion Starter #6
Thanks everyone. I changed the battery this afternoon and seems to have resolved the problem. If it returns, I'll let everyone know.

Thanks again,
John


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Sometimes life is just that simple. :woot:
 

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If this has all been said before, sorry. But I searched and couldn't find a clear, definitive answer anywhere:

I finally got time and inclination to do an experiment to see if the car can be started with a dead fob battery. My car has pushbutton start, and I know that if the fob battery is totally dead, it won't start with the button. I carry a couple of 2032 batteries in the glove box just in case, but I know I'd have to sit there and fiddle with the fob to replace the battery while the alarm is going off annoying everyone around me. So I decided to see if the trick of popping the start pushbutton out and inserting the fob and twisting it like a key would work with the battery completely out of the fob.

With the battery out, of course you get a "key fob not detected" error, and the car won't start, door won't unlock, etc. except with the metal key from the rear end of the fob. But if you pop the pushbutton out and insert the fob, the car WILL start with NO battery in the fob. The flashing antitheft light goes off as soon as you insert the fob in the socket

My assumption is that the RFID interrogator antenna is built into the socket on the dash, and the fob has to be physically inserted for the interrogator to correctly read the RFID chip without the battery to transmit the code over the keyless entry RF system. Its pretty clear the fobs have two independent RF systems that talk to the car- long range keyless entry and start that uses the 2032 battery, and a short range battery-less RFID like older SKIS/SKIM metal keys had.

So- if your fob's dead, pop out the pushbutton, insert the fob, drive home, and change the battery at your convenience. :D
 

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^^^ When I bought the 09, the dealer told me that the car would start with the fob in the ignition even with a dead or no fob battery. I tested this as soon as I got the car home and found it to be true.

I replace the fob batteries once a year and it has virtually eliminated fob detect and any other fob issues we had with both the Challenger and Jeep. Very cheap insurance.
 
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