Key Fobs and LED interference

[Ronkartz72]

Still no problems on my end.

 

[jafoesq]

I put in the Lasfits in the cargo lights and 3rd brake light and am having "Key Fob Not Found" issues. If I get in after the truck sitting for a while I get the error. If it's been running a while I can kill the truck and restart with no problem. Has anyone else had any issues with the Lasfits?

 

[djjr50]

Anybody using 3rd brake LED from Lasfit? Does it interference with our FOB?

Had mine for a few months now and no issue.

 

[Jayturk]

I have those and I am having intermittent issues.

I replaced my LED's with the stock bulbs and no issues whatsoever. I had to take my truck in for the dreaded sliding rear window and had them check out the "Key fob has left the vehicle" and "Key Fob not detected." Of course they were not able to reproduce the warnings but left the attached in the vehicle.

 

[Scott_65]

That’s why you pay the extra and get Diode Dynamics, zero issues since installed.

 

[SpeedyV]

That’s why you pay the extra and get Diode Dynamics, zero issues since installed.

Well, knock on wood, but zero issues with my Amazon cheapies for the past 18 months.

 

[Scott_65]

Well, knock on wood, but zero issues with my Amazon cheapies for the past 18 months.

Glad to hear but hopefully you didn’t just jinx yourself

 

[dschweers]

Anybody using 3rd brake LED from Lasfit? Does it interference with our FOB?

I did and have a return

Anybody using 3rd brake LED from Lasfit? Does it interference with our FOB?

Yes they interfere will be pulling out this afternoon. Returning as they said they could not fix this. They paid postage also and crediting my card.

 

[Shives]

Ok guys your all missing a huge step.
First our trucks can come with LED lights. Their is programming that MUST BE ENABLED for things to not get stupid. Regular lights have voltage differences and LED forward voltage difference when not seen the BCM will go nuts. Get Alfa OBD and go to BCM go to the LED light section and enable CHMSL led present yes. Rather NO.
Your welcome.
If your in western mass, happy to help seeing I have the hardware

 

[Skater]

I did and have a return

Yes they interfere will be pulling out this afternoon. Returning as they said they could not fix this. They paid postage also and crediting my card.

LasFit 3rd brake light and cargo lights for a month, no issues with my Ram.

 

[Bruins5515]

Has anyone noticed that there key fob is less responsive after changing the interior lights out for LED, i used Lastfit LED and noticed now if i try to hit unlock or lock multiple times after the first time it doesn’t respond. Once the interior lights turn on from first push of the button the fob doesn’t respond till i am really close to vehicle. I turned the interior lights off and it works fine.

 

[turkeydinneronapizza]

I recently installed Lasfits in my CHMSL as well as replaced all my interior bulbs and am running into the occasional key fob issue. Most of the time there is no problem, but every once and a while it will not register the lock/unlock or will say the fob is not in the vehicle and won't start. Given it is not frequent, I'll give it a go for a while and if it continues I may swap the CHMSL bulbs to a different brand. Been playing around with it and I am finding a few situations where the fob is more likely to throw an error:

• Starting the truck with a door open (causes all three CHMSL bulbs to be on at the same time while trying to start the truck)
• Keeping foot on brake for some time before pressing the ignition button
• Pressing the fob too many times while the lights are on
• If there's an area where the connectivity is generally poor (eg. in my parking garage which has a steel roof and concrete walls)

90% of the time there are no issues, but I'm trying to reduce some of these situations and see if it makes a difference.

 

[Dj0mladen]

I figured out little bit of a trick. If you are about to start the car dont press the break push start first which will turn the accessory mode or whatever is called and than step on the break and push start again you will be able to turn the car without taking your key out of your pocket.

 

[Shives]

I figured out a trick too! Program your truck to accept the correct bulb, and have ZERO issues.
Ask me how I know. Lol

Again, if you don’t have AlfaOBD then get it, or find someone who does! Enable each light for LED that you’ve replaced. Trust me, each light has a location and option for LED!!! Even the plate lights!
So, program your truck and finish the mod properly! I can’t tell you how the other trucks are not having issues, I can only tell you how to fix it and where.

 

[brian42]

Has anyone noticed that there key fob is less responsive after changing the interior lights out for LED, i used Lastfit LED and noticed now if i try to hit unlock or lock multiple times after the first time it doesn’t respond. Once the interior lights turn on from first push of the button the fob doesn’t respond till i am really close to vehicle. I turned the interior lights off and it works fine.

LASFIT in CHSML and all interior lights with no issues.

 

[RyanZ]

I figured out a trick too! Program your truck to accept the correct bulb, and have ZERO issues.
Ask me how I know. Lol

Again, if you don’t have AlfaOBD then get it, or find someone who does! Enable each light for LED that you’ve replaced. Trust me, each light has a location and option for LED!!! Even the plate lights!
So, program your truck and finish the mod properly! I can’t tell you how the other trucks are not having issues, I can only tell you how to fix it and where.

Do you have a guide or steps to do this? I have AlfaOBD and lasfits and started running into this keyfob interference issue.

 

[Shives]

Do you have a guide or steps to do this? I have AlfaOBD and lasfits and started running into this keyfob interference issue.

I don’t but I can try to walk you through it. DM me.

 

[UnloosedChewtoy]

Started having issues here as well with LASFIT. Put in Diode Dynamics, and they aren't quite as bright because they don't have any LEDs pointing straight out, they rely on the reflectors. However, no more interference issues.

If it truly is interference, I do not see how telling the computer that there are LEDs will help. If the computer was triggering a bulb out warning or something, it would help with that, but interference is not caused because the computer doesn't know its LEDs, interference is caused by cheap or low-grade LEDs.

If anyone had the issue, and setting the computer to LED 3rd brake lights resolves it, I'm all ears; would be happy to be proven wrong.

 

[Jimmy07]

Started having issues here as well with LASFIT. Put in Diode Dynamics, and they aren't quite as bright because they don't have any LEDs pointing straight out, they rely on the reflectors. However, no more interference issues.

If it truly is interference, I do not see how telling the computer that there are LEDs will help. If the computer was triggering a bulb out warning or something, it would help with that, but interference is not caused because the computer doesn't know its LEDs, interference is caused by cheap or low-grade LEDs.

If anyone had the issue, and setting the computer to LED 3rd brake lights resolves it, I'm all ears; would be happy to be proven wrong.

Let’s start with the actual reason why LEDs cause the key fob to not be detected. Every LED (the actual light emitting diode chip) needs some kind of driver to operate, and the drivers naturally emit high frequency, which in turn generates electromagnetic interference. Manufacturers correct this by adding some sort of filtering, usually in the form of a “canbus error canceller” or “anti flicker” device, but in replacement bulbs of this size, they build the filter right onto the bulb board. The RF Hub on Ram trucks (the receiver for the fobs and TPMS system) is located on the back wall pretty much directly below the CHMSL. Since the brake pedal needs to be pressed to start the truck....well, we all know the rest. The BCM on our trucks uses PWM (pulse width modulation) on all exterior light circuits that use halogen bulbs. This PWM rapidly turns the circuit on and off in different duty cycles to extend bulb life and prevent dimming when the alternator is under heavy load. When a truck is optioned with LEDs in particular locations, the BCM is configured to not use PWM on those circuits. That is what AlfaOBD is doing when you enable or disable the LED locations in the CBC Features list. If an LED manufacturer implements crude or poor filtering circuits, the PWM can disrupt the filter’s ability to start doing it’s job, and allow EMI to be generated. Since most LEDs are manufactured in uncontrolled environments, any LED is capable of doing this. That’s why some will say “this bulb worked for me”, but the same one doesn’t for others, no matter who the manufacturer is. Using AlfaOBD to disable the PWM on the CHMSL is not guaranteed to stop this interference all together, but greatly reduces the chances of it happening. Obviously, if somebody finds a bulb that works for them, then there’s no reason to buy AlfaOBD just for that, but if you already have AlfaOBD, it will give you more leeway on bulb selection.

 

[ZonaRam44]

I replaced the two white cargo light bulbs right after I got the truck. Then later I replaced the third break light. I started getting the "keyfob not detected" error, but I had no idea why. I'm glad I came across this thread. I replaced the third break light with the factory bulb and I have not had that issue again. Its been a couple weeks now so I'm happy. I might try another red LED, but I might just leave it alone.