DTL are high beams after LED bulb change
 

Hello all,

I upgraded the headlights in my 2009 Accent to Philips X-tremeUltinon LED bulbs, and although they work and are very bright, they certainly aren't quite as plug-and-play as they claim. When I turn the car on and release the parking brake the daytime running lights come on, however they are the full power high beams. The second position on the light switch is the same thing. Only when I move the switch to the headlight ON position do the headlights dim, at which point the headlights and high beams work normally. There is perhaps a very slight flicker on the daytime running lights, but I can't recall if I noticed this on the high beam setting.

It is my understanding that some vehicles use the high beam filament at a lower or pulse-width modulated voltage for your daytime running lights, which would explain this scenario. Is this an issue that could be resolved with a canbus resistor like this:


They seem to resolve a number of issues, however my specific issue isn't listed. I'm not getting any error codes.

For the time being I am conscious to always have my headlight ON when driving so I'm not blinding other drivers, but I would like to resolve the issues permanently.

Cheers!

Depending on your local state laws, you might want to check this out. Just because they sell the LEDs does not make them legal in certain states.
Some law enforcement agencies require either the vehicle came with them or they have to be DOT compliant.
Some vehicle inspection locations will not pass the vehicle if there is any question regarding the use of them. Worth looking into that.

Thanks for the reply. These particular headlights are DOT/SAE approved so they shouldn't be a problem. I just need to address the high-beam issue, and it's probably not a bad idea to make sure they are adjusted properly too.

Unless the LEDs are accompanied by the proper reflective path , they can blind other drivers.
OEM make provisions for that whereas add on s , don't and that is where the problem starts.

Well, after doing a bit more research it looks like I will have to switch back to the woefully under-powered halogen headlights. Evidently LED bulbs are for use strictly with high and low beams, the high beams will NOT dim for DRLs. I suppose I could install some fog lights and relays and mess around with a rat's nest of wiring and disable the DRLs (if that's even possible on this car?), but that seems like a bit much.

I must say that with the headlights on (on "low," not the high beams) the beam spread was pretty much perfect. Very similar to halogens, but obviously much brighter. I really do not think that they would have blinded anyone, except the fact that the DRLs were just full-powered high beams. Not worth risking my own or anyone else's safety in the off chance I forget to turn the lights on one day.

It's really disappointing that even a company as big as Philips can't, or won't, figure out a way to interpret the lower voltage/PWM voltage and simply dim the highbeams.

The lamps are designed to do a job. How they are controlled to do that job is affected by whether the headlights are turned on for night driving or not.When DRL function is operative , a module is supposed to have the high beams operate at a lower voltage to prevent high intensity light during times the headlights are not required for safe night time driving . Night time driving with better lighting is all about contrast and that is how vision is improved.