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Key FOB transmit range has suddenly decreased

bpotter

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I used to be able to auto-start my '19 Longhorn from the 4th floor at work all the way down to the parking lot. About a month ago, the range suddenly decreased and now I typically need to be within 40 feet or so for auto-start or unlock to work!

I switched to a new premium battery, tried the other key FOB (with new battery too), but nothing seems to have helped. Anybody else run into a severely-limited key FOB range?

Thanks... Brian
 
Is there anything plugged into your OBD2 port? On my 2012, I found that leaving my Trinity tuner plugged in dramatically reduced the range of my fob.

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I used to be able to auto-start my '19 Longhorn from the 4th floor at work all the way down to the parking lot. About a month ago, the range suddenly decreased and now I typically need to be within 40 feet or so for auto-start or unlock to work!

I switched to a new premium battery, tried the other key FOB (with new battery too), but nothing seems to have helped. Anybody else run into a severely-limited key FOB range?

Thanks... Brian
You didn’t happen to install any LED lighting?
 
You didn’t happen to install any LED lighting?

Well, even if he did, LEDs don't cause interference until they're on, which isn't the case with remote start.


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Most likely something in your office is generating RFI or radio frequency interference in the broadband range. I believe our vehicles operate in the 315mhz range. There are several things that might introduce interference such as LED lighting and WiFi routers in your building, amongst others things. There are also environmental factors with weather, positioning, etc that might cause RFI to become more prevalent. Unfortunately you probably won’t be able to correct your problem short of creating a special key fob for your office with either an amplified signal or better antenna (which is possible) :D
 
How does it behave the same when you're not near your office?

That's the thing, reception is poor regardless of where I'm at, which makes me think it's something onboard the truck. Anyone know the trunk's antenna location for the FOB?
 
Is there anything plugged into your OBD2 port? On my 2012, I found that leaving my Trinity tuner plugged in dramatically reduced the range of my fob.

Sent from my Pixel 2 XL using Tapatalk
Nothing plugged into the OCD2 port.
 
That's the thing, reception is poor regardless of where I'm at, which makes me think it's something onboard the truck. Anyone know the trunk's antenna location for the FOB?
Seems like some have had limited success pulling the battery power (pull the negative lead) for 15 + minutes, reattach and let it sit for a while before starting, etc. to clear weird electronic issues. Worth a shot.
 
Could be the module/receiver but my guess would be that would be an all or nothing thing, meaning fob wouldn’t work at all but who knows. I’m not sure where it’s located but maybe something is causing interference, if it’s block by something new that was installed or gunked up with salt, etc. Maybe do some straight line of sight testing in a clean open environment.
 
I would be surprised if nearby WiFi could be causing an issue, given that the RKE (remote keyless entry) fobs in the US operate at a nominal 315 MHz, and most WiFi in the US is 2400-2500 MHz (and some dual-band WiFi routers having an additional ~5000 MHz band).
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That said, there could be other RF (radio-frequency) sources in the area that are closer to the nominal 315 MHz of these US keyfobs (factory-issued anyway - no telling what aftermarket products might operate at).
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Maybe Ram did a software update on purpose to reduce the range, for security reasons? Just thinking out loud.
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I would be surprised if nearby WiFi could be causing an issue, given that the RKE (remote keyless entry) fobs in the US operate at a nominal 315 MHz, and most WiFi in the US is 2400-2500 MHz (and some dual-band WiFi routers having an additional ~5000 MHz band).
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This is very true. It was just an example but true that traditional WiFi routers are higher band. Chasing down RFI can be a bear. If you happen to be near a military base they use tons of stuff in that range. Police also use equipment in that range. PCs will use stuff in the lower MHz range but with harmonic distortion it can get up there. You can also have intermodulation which will combine frequencies and cause you interference. It can also be a reflection issue. Anyway, I’m off in a tangent. Fun stuff though :D Seems like OP is having the problem is other places though so it sounds like it is a fob/receiver/software issue maybe.
 
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Some good thoughts! Now I'm wondering if the recently-added dash cam, running in parking mode, could be there culprit?

I'll check it out and let you guys know.
 

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