I have a 2017 STX and recently upgraded most of the lightbulbs to LEDs, including headlights, turns, reverse lights, license plate lights, and cargos. Since then, I've experienced two issues:

1) Sometimes the key fob doesn't like the cargo lights; and
2) Headlights are always on on auto headlight setting.

I did a bit of research and found that the key fob issue is pretty common when upgrading the cargo lights. I'm not a wizard, but it has something to do with the electronic signal put out by the lights that interferes with the key fob's signal to the truck. It's annoying sometimes, but I just have to wait a few seconds and the truck will respond to the lock signal.

Despite my research, I could not find an answer to my headlight problem. Now, whenever my headlights are set to auto, they are always on despite the time of day or amount of light they are getting. It's not the DRL--those are turned off. The radio and dash dim, and the headlights come on no matter what. Has anyone else experienced this, and is there a way to fix it? Maybe a forscan option I'm not aware of?

Thanks

 

The computer program for lighting is a bit different on stock LED equipped trucks than on Incandescent equipage.
Might not think this is so but today, everything that draws current is controlled in these trucks.
Lighting is highly controlled and monitored through modules that are programmable.
Good luck.

 

My neighbor put led headlight assemblies in his 18 and has all kinds of fun issues. He had it in to the dealer 3 or 4 times for radio intermittent humming/static before the internal bulletin came down that it is the aftermarket lights. Turns out the suppliers knew about this issue and sold them any way.

 

I put LED bulbs in an old Sable I had and they wreaked havoc with the radio as well.
Don't know why especially since the antenna was at the back.

Put regular bulbs back in and the radio static disappeared.

I have not touched my truck lights.

 

In many multi element light assemblies that appear as they are all lighted; there is an electronic controller that pulses each element on and off in sequence. The speed this is done is so fast they all appear to light at the same time. Your eyes and brain integrate the time into one bright light.
The on / off sequence is what causes the interference. The on/off square wave is an attempt to lower the average power consumption in order to get more brightness by spike driving the LED segments. The sequence is likely done by an Oscillator driving a ring counter action controlling solid state switches to each segment. These controllers are all sub-miniature and fit into small spaces.
In addition, the truck electronics are monitoring this behavior and only expect to detect original equipage function.
Not knowing this, you make a radical change and now the system displays issues.
You cannot just change things at will unless the change can be accepted by the system, in some way..
Gone are the day when you just switched 12 volts on to the the lights.
Even if you did this on a truck as separate lights, they may/could/might still create interference by >>radiation off the wiring..
All this may sound complicated but this is where we are now. There is no going back.
Good luck.

 

Stop setting the headlights to auto.

 

The headlights on all the time in auto may be related to DRL. The LED run at much less current and do not have a DRL function but either on or off, DRL in a halogen equipped vehicle reduces the current during day time operation. If using the auto position and DRL the LED's will be full brightness all the time. The flickering may be more to do with the drivers conversion of supplied electricity, I only have LED headlights in my own XL. KM

 

That would make sense, but I have DRLs off. So when in auto, the headlights shouldn't be drawing any power until a turn signal is turned on. Bluegrass's apocalyptic answer might be the best explanation, that there is some interference from the lights when the truck is started that causes the auto headlights to turn, and stay on. I admittedly don't know much about electronics, but would resistors on the headlight LEDs prevent that interference, or is that unrelated?

 

Since the automotive adoption of the 1986 CAN bus protocol, wiring and automotive electrics jumped into the computer age, I gave up trying to figure it out. KM

 

Apocalyptic it may be, and Bluegrass is right. It's not as easy as it used to be. Light switches used to just be directly wired to the lights that they were powering. Now the switches just send a hexadecimal signal to a computer saying I've been activated, now you do your part and turn it on. That's the sciency **** about it, but as a mechanic and installer I would first ask A) what brand are the bulbs, and please don't say I got them on Amazon, and B) I assume there is nothing on your dashboard blocking the ambient light sensor that actually activates the auto headlamps, right?

The number one issues that I have seen with LED installs is not doing your homework, and buying cheap bulbs. I have never seen them turn themselves on unless some other demon is at play, such as the light sensor on the dash being blocked. Cheap bulbs can have many demons, noisey operation, poor light output due to the bulb being too wide where the LEDs are mounted, and radio frequency interference from those cheap *** fans on the back of some of them. Typically you can remedy incorrect operation with PWM modules/anti flicker modules. Again, you don't want the cheaper ones here either. I've had issues with those too. I installed Putco Silverlux bulbs in my old truck and the lights would work fine until I started the truck and then the high beams would kick on everytime I turned on the fogs. I put cheap plug and play anti flickers in it and all it did was delay one side from turning brights on for about 2 seconds. I installed RaceSport lighting anti flickers in on the fogs and that cured that issue. My new truck I just installed Morimoto 2 stroke 3.0s in and they worked great until I started the truck. Then they would blink twice and shut off. I just put Tiny Monster PWM modules/anti flickers in last night and they work flawlessly. GTR lighting also makes some that are supposed to be good as well.