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Key Fob Not Detected-Simple Fix

171K views 43 replies 31 participants last post by  Bad daytona  
#1 ·
This morning, the message appeared when I tried to start my 2009 SRT with about 18000 miles. I retrieved the spare fob from the keybox and it, too, would not work.

After popping the start button and using the fob like a key, I drove to work thinking the Entry Module failed. Why not? I have a 13 year old Neon with the original remote battery...the batteries must last forever.

Not so. I tested one fob battery and it was a 2.4v; replaced it with a new one (3.4v) and everything worked. It seems a coincidence that the batteries failed in both fobs despite one never being used.

But that wasn't the only coincidence today. Driving home on I-85, I came up on another black Challenger and we pushed the left lane for all traffic would tolerate for about 5 miles. At the next to last exit for me, a third black Challenger joined us. How often does one see three black Challengers in a row on an Interstate highway? Got to be a good omen.
 
#4 ·
If you leave the key fob in the car I think the ignition and the key fob constantly "talk" to each other draining the battery. That's how range rovers are.
 
#5 ·
If they are constantly pinging each other when the fob is within range, could we extend battery life by putting the keys in a steel container (Faraday cage) instead of on the dresser or key hook? :scratchhead:
 
#6 · (Edited)
The "key" is distance. If you leave the keys in the house instead of your pocket when working on your Challenger, it's too far to send a signal anywhere and the remote won't attempt to communicte at all. I found the same with BMW remotes, keeping them away from the vehicles kept the cars from "waking up" and having unnecessary electronics and electrical systems come into play when they were not needed. Keeping the key fobs close always places those systems in the ready mode.

So, now we leave the keys on hooks at the back door about 30 feet away from the car and yes, the panic alarm will still work, but you can't lock or unlock with the door handles, as nothing is communicating. You can still press the buttons to lock and unlock the car on the remote and they too will work IF you have fresh batteries in the remotes. But again, no automatic or two-way communications with the modules in the vehicle. If you need the keys when you're working on the car, carry them, if not, put them on the rack.

Finally, I change the batteries in the remotes every 6 months or less on the Keyless Enter and Go or Keyless / Convenience Entry ones.Probably once a year is fine on the regular remotes without the Keyless Enter and Go feature, unless you use your remote a lot. Cheap enough insurance against problems. The CR2032 Sony or Panasonic or Maxell that I consider good brands are available on eBay for about 50C each if you buy ten at a time (some other models cost two bucks for the imported cars, but still less than the dealer, or even if warranteed, a trip to the dealer) And much less than a lockout!

Even though you are told those lithium batteries will last 8 years in your watch, how many watches have you had that they actually make it the full 8 years? And doesn't the watch usually quit just when you really needed to know the exact time? Just like the remotes!
 
#11 ·
Pry it apart with the emergency door key. There is a slot on the bottom end it fits into and twist or pry - carefully.

Some are different like our Jeep, it has a battery door on the back.
 
#12 ·
The battery in the key fob is a Panasonic CR2032. I went to Walgreen's and purchased a set of two Energizer batteries for $6.99.

The replacement steps are very easy (don't go to the dealer):

1. Remove the valet key by pushing on the slide and pulling it straight out.
2. Using a thin-bladed screwdriver or a knife edge, unsnap the key fob by gently prying around all of the edges.
3. One the key fob splits apart, simply pull out the old battery and insert the new one. (Don't worry, unlike some watches, there are no loose parts inside).
4. Handle the new battery around the edges and push it into place using your thumb and index finger (Tip- Use a small piece of paper towel to avoid getting any hand oil on the new battery and angle the battery in towards the silver retaining clips).
5. Align the two halves of the key fob and snap them together.
6. Reinsert your valet key.
7. Test your locks to insure that they are working.

You are done (less than 5 minutes)!

Here is a photo of a disassembled key fob.
 

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#14 ·
really cool write up, thank you. I figured you had to pry, but did not want to destroy my key on a 50/50.

Too many times have I strong armed somthing, broke it and then figure out there was a hidden switch or a backwards screw.
 
#15 ·
I just got a warning today on the EVIC that the battery in the FOB was low and needed to be replaced. A short time thereafter I got a system warning as I was driving (again on the EVIC) that the battery was low in the FOB. It looks like the last Flash I got had this extra info in it. :thumbsup:
 
#16 ·
I just got a warning today on the EVIC that the battery in the FOB was low and needed to be replaced. A short time thereafter I got a system warning as I was driving (again on the EVIC) that the battery was low in the FOB. It looks like the last Flash I got had this extra info in it. :thumbsup:
I wasn't aware that the car sent that message when batteries were low.
 
#17 ·
My 2010 went thru the fob batteries in less than 18 months. One died 3 or 4 months before the other, so went to dodge and got new batteries, and they have worked fine ever since, did get the message again a couple days ago, but I just cycled the door locks and it worked just fine afterwards.

I used to eat lunch daily in the car while at work, listening to the radio for 45 minutes, and think that ate thru the batteries quicker.
 
#18 ·
My 2010 went thru the fob batteries in less than 18 months. One died 3 or 4 months before the other, so went to dodge and got new batteries, and they have worked fine ever since, did get the message again a couple days ago, but I just cycled the door locks and it worked just fine afterwards.

I used to eat lunch daily in the car while at work, listening to the radio for 45 minutes, and think that ate thru the batteries quicker.
Didn't you read the owners manual????
NO EATING IN THE CHALLENGER! :no:
 
#19 ·
lol, I eat drink and smoke in mine, breaking all the rules evidently. Then again i don't care about resale value as it will probably be with me till it hits 120k miles.
 
#20 ·
I eat, drink and used to smoke in mine as well (I quit 4 months ago).

My car, my rules :icon_cool:
 
#23 ·
trouble with 1 keyfob

Knowing we have 2 fobs to work with,I have had alot of trouble with just 1.The same one.They say you are suppose to switch off,so the car can learn them,I can only use one that works.The other always says''keyfob not detected''.Frankly,this makes me mad.It has seemed to always be like this for the most part.I think,I will have to take it to Dodge and get it reprogrammed.The price they want,is crazy though.I guess I have no choice.I have to have a back-up.What ya all think on this?
 
#24 ·
if it says key fob not detected, first thing to do is change the batteries, chances are that the battery has died in that one, instead of replacing it. I had to change the battery in mine within a year after I bought it. As for programming it the dealer shouldn't charge much to get your fob to relearn the programming, only if you buy a new one should they charge you for that.
 
#27 ·
Buy the batteries in bulk from eBay; buy quality such as Sony or Panasonic or Maxell. Be sure they are dated at least 7 or more years ahead of the date you buy them (they will say in the ad or on the packs) and change them out about every 6 months. Very cheap insurance against dead fobs.

I find the biggest issue with fobs is them being in your pocket and pressing on something else when you sit. That can have a button depressed for a long time and wear out the battery in short order, leaving you wondering why it went bad so fast. I am all too aware of that as when in the garage, I often see the lights/horn flash as I either trigger the alarm on or off unintentionally with the fob and other stuff in a pocket. Carrying it around the car will also activate the readiness feature so the vehicle is "awake" and receptive to keyless entry, etc.

In any event, we have numerous cars and changing the batteries reduces the number of times the "key fob not detected" appears. As a side note, you can still get that in your EVIC with a fresh battery. Just move the fob in your pocket away from your other keys and it should work. Happens with the Dodge, BMW and others as well. Fickle beasts.
 
#28 ·
I tended to sit in the car at lunch while at work and listen to the radio for 45 minutes each day, I think if the cars in accessory mode its in constant communication to the fob which may prematurely wear the battery out some. Still, some last longer than others. The batteries weren't very expensive at the dealership.
 
#29 ·
I replaced both batteries for both fobs.Still the same problem.When the car is out of storage I might run to Dodge and see what they can do_Only thing I can do I guess.Thanks for the info :)
 
#30 ·
I'm not going to act like I know how the key works, but some of the logic here just doesn't make much common sense.

If a keyfob is always talking, sending out pings (running down the battery) then that makes sense that the car would know its in proximity.

However, for those that are saying that once it gets a certain distance away it stops sending pings to conserve battery that does not make sense. If it did that how would it ever know it got back within proximity without sending ping. Sending the ping is how it calculates distance.

What likely happens is it sends a low powered ping every few seconds regardless of where the keyfob is. In fact, the one place it might conserve power is when its actually in the car. It very well may ping less often if the last ping was successful.
 
#32 · (Edited)
Would there be anything detrimental to removing the battery from the FOBs or a FOB if you're planning on storing the car for the winter anyways? I'm guessing that the memory in the FOB doesn't need to keep power supplied to retain data since the fob continues to work after changing batteries.

Take it easy
Jay
 
#38 ·
The win module is bad. This is a known problem to dodge and the dealers. This is the module that detects the fob. Replacing. the batt is not what made it work again. This problem is intermittent and I had it happen a few times to me. Put the key in and drive it and the next time you get in it works just fine. It will go out on you eventually. If its under warranty you get it replaced free. If not and you cant do it yourself it will cost you. I was told by the dealer not to start the car with the key but call them and get it towed to the dealer. The reason is they need to pull the code to fix it under the warranty.