Key Fob Not Detected.....but....it's in my pocket!

[The_Chemist]

So I’m thinking ( my wife says it doesn’t happen that often!) that if the manufacturer has equipped the vehicle with LED’s throughout the entire vehicle, but left the centre brake light with incandescent bulbs, there must be a reason. I’m betting that tests indicated that the centre brake light equipped with LED’s caused interference issues with at least a few builds.

Makes sense. I do believe the antenna for the fob is in the shark fin on the roof, right above the 3rd brake light.

 

[Gman]

How would the LED bulbs interfere when they're not even energized?

 

[Neurobit]

So I’m thinking ( my wife says it doesn’t happen that often!) that if the manufacturer has equipped the vehicle with LED’s throughout the entire vehicle, but left the centre brake light with incandescent bulbs, there must be a reason. I’m betting that tests indicated that the centre brake light equipped with LED’s caused interference issues with at least a few builds.

I would have agreed with you, except that I had this happen to me a couple of times with factory bulbs... Not nearly as often as when I had the cheapo LEDs, but it did happen.

 

[Neurobit]

I always keep my phone in a pocket dedicated to just the phone, so I've never encountered that. I did have a problem with 2 proximity keys in the same pocket from 2 different mfrs. (although never with my Ram). My Hyundai proximity key always worked. My Mercedes Benz would get confused and act like there was no key. Then again, it would often get confused with only the correct proximity key. I've really not had any issues with the Ram (and I've had 2 different 3rd brake LEDs and cargo LEDs). Even leaving the vehicle running and getting out to get the mail and coming back automatically resolves itself.

I don't have an answer. Could be that some current does go through and causes this. I just DK.

 

[The_Chemist]

How would the LED bulbs interfere when they're not even energized?

When you start the truck, you have to put your foot on the brake pedal which illuminates the 3rd brake light right by the key fob antenna.

 

[Edwards]

When you start the truck, you have to put your foot on the brake pedal which illuminates the 3rd brake light right by the key fob antenna.

I can't recall where but someone posted the antenna locations (there are several) but I don't think there was one in the shark fin. Also, there are two types of antennas for the two frequencies used by the fobs. One is for long-range things like lock, unlock, remote start, etc. and the other is for short-range things like dash button start and passive entry. That frequency/antenna would be the one in question here.

I do recall someone posting the exact frequencies used as well.

 

[Neurobit]

I can't recall where but someone posted the antenna locations (there are several) but I don't think there was one in the shark fin. Also, there are two types of antennas for the two frequencies used by the fobs. One is for long-range things like lock, unlock, remote start, etc. and the other is for short-range things like dash button start and passive entry. That frequency/antenna would be the one in question here.

I do recall someone posting the exact frequencies used as well.

That was prob me. Here's the document again. t has the location for all the antennas (Low Freq and Remote Start).

Cheers,

 

[Neurobit]

Here's the other doc:

 

[Gman]

Here's the other doc:

Awesome! I got to the link in the first doc and then got prompted for a login.

I had been looking at the Remote Start Mopar aftermarket kit and I did see the Radio Frequency Hub near the CMHL (but not the fin). That got me into thinking about the lights not being energized during remote start (forgetting that this is a Keyless Go issue). I did see that there was a passive entry antenna in the center console while reading the installation instructions.

Based on the 2nd doc, there are Low Frequency antennas in each rear door, the rear cab wall behind the seats, and at the tailgate.

 

[The_Chemist]

Here's the other doc:

Thanks for posting those.

Now this really has me thinking. I read that there was an LF antenna in the center console.

My center console was replaced by the dealer because they damaged it taking my interior apart to get a bolt out of the heater box that was rolling around in there. Of course the bolt was left in there courtesy of the factory's lack of care and quality.

I'm just wondering if the console antenna is now missing or dusconnected?

 

[Neurobit]

Thanks for posting those.

Now this really has me thinking. I read that there was an LF antenna in the center console.

My center console was replaced by the dealer because they damaged it taking my interior apart to get a bolt out of the heater box that was rolling around in there. Of course the bolt was left in there courtesy of the factory's lack of care and quality.

I'm just wondering if the console antenna is now missing or dusconnected?
View attachment 39784

Could be...

 

[The_Chemist]

Could be...

Just to ward off all evil spirits, I reinstalled all 3 original factory incandescent bulbs in the 3rd brake light housing.

I'll see how it goes for a few days. If I get no "key fob not detected" error, I'll consider the console antenna functional.

I wish I knew where in the console it was exactly... And I wish there were a way to test its functionality that I could easily do.

Next, after all is considered well, I'll install the Diode Dynamics LED that @Neurobit recommend and has verified works without issue.

Man, I hope I don't get a water leak at the 3rd brake light housing from taking it in and out so many times! That would just be my luck with this lemon truck.

Last count, the dealer had $15,000 in parts installed to correct factory defects before the new rear differential was installed. I don't know what the tally is now.

At least FCA gave me an extended warranty on the truck.

 

[VinnyRam]

Installed the LED 3rd brake lights yesterday and got the key fob not detected error twice today.

 

[The_Chemist]

Installed the LED 3rd brake lights yesterday and got the key fob not detected error twice today.

What brand and model number did you install?

I took my cheap LEDs out and reinstalled the original incandescent bulbs that were in from the factory. I have not had the "key fob not detected" error since. It's been a week now.

I did purchase a Diode Dynamics HP5 to try but haven't installed it yet. Another Forum member recommend it. He said he gets no error with that particular LED.

It's weird because when I first installed the cheap LEDs I got no key fob error. It all started after my center console was replaced by the dealer. Just wondering if they forgot to transfer over the LF antenna.

 

[VinnyRam]

What brand and model number did you install?

I took my cheap LEDs out and reinstalled the original incandescent bulbs that were in from the factory. I have not had the "key fob not detected" error since. It's been a week now.

I did purchase a Diode Dynamics HP5 to try but haven't installed it yet. Another Forum member recommend it. He said he gets no error with that particular LED.

It's weird because when I first installed the cheap LEDs I got no key fob error. It all started after my center console was replaced by the dealer. Just wondering if they forgot to transfer over the LF antenna.

Got these from Amazon.

 

[Neurobit]

What brand and model number did you install?

I took my cheap LEDs out and reinstalled the original incandescent bulbs that were in from the factory. I have not had the "key fob not detected" error since. It's been a week now.

I did purchase a Diode Dynamics HP5 to try but haven't installed it yet. Another Forum member recommend it. He said he gets no error with that particular LED.

It's weird because when I first installed the cheap LEDs I got no key fob error. It all started after my center console was replaced by the dealer. Just wondering if they forgot to transfer over the LF antenna.

More than likely it’s the bulbs, not the antenna. Waiting to hear about your DD bulbs. Mine work great still.

 

[VinnyRam]

I used LEDs I found on Amazon and have no error codes or key fob issues. The bulbs did show they were compatible with the RAM and compatible with CANBUS without any resistors or other wiring changes. Your mileage may vary.

Could you please post the link? Thanks

 

[Gman]

Could you please post the link? Thanks

Cargo Lights: https://www.amazon.com/gp/product/B01LX4FMD1/

Strobing 3rd Brake Light: https://www.amazon.com/gp/product/B07QMH9HYJ/

 

[Patsy1099]

So I’ve had this issue happen to mean sporadically. Also have the 3rd brake light leds installed. What I have found works for me every time so far is the following:

- get into car, press brake and start button
- if you get message fob not detected
- take foot OFF of brake and leave it off. Then press start button (without foot on the brake)

That seems to work for me every time now. Not sure why. It seems counterintuitive but maybe as stated above it has something to do with the sensor being in the same area as the brake light and by not pressing brake it fixes it?

 

[RobertB67]

Hi all,
I been having the same problem with my 2019 RAM1500 Big Horn Crew Cab, I started to get "key fob not detected" about a month after I had the truck.
I's been in the shop now 6 times for the "key fob not detected" problem, they can not figure it out.
I also replaced the 3rd break light with LED, I can not believe that would be the cause of this whole "key fob not detected" problem. But I'm going to the dealer and putting the original incandescent bulbs in and see if it fixed the problem. I also replaced all incandescent bulbs inside the truck as well as head & tail lights.