Daytime running lights are a lamps that are automatically controlled by your vehicles system and typically run during the day and is shared to the same high beam bulb but at a reduced intensity. Some cars have dedicated daytime running lights that are separate from the headlamp applications. If your vehicle’s DRL is separate then your car is one of the lucky few that will never run into a flickering problem on the DRL system when running aftermarket LED headlamps.
For those that have experienced a dreadful flicker on their Toyota, this article may be geared towards your situation.
First, you must understand how a daytime running light system works. You know what it is, but how does it turn on?
Most vehicles will be programmed to meet certain conditions in order for the DRL system to actually turn on. The headlight switch must be set to AUTO, gear must be in DRIVE or not PARK, and there will usually be a sensor on the vehicle’s dashboard which detects light. Once the conditions are met, your vehicles system will immediately supply a reduced current to dim the factory high beam bulb. This applies to most Toyota’s with DRL’s and high beams on the same circuit. To understand if your vehicle runs high beams and DRLs on the same lamps, you may either physical test the lamps or consult the owner’s manual. You may also reach out to JDM Astar for any guidance.
Once the DRL system engages, BOOM! You get the fast flicker on your LED headlights!
So how do you fix this flickering issue as it is not controlled by a CANBUS system that is monitoring the lamps for problems?
Well, the fix is very simple and after extensive research and testing of various model Toyota’s with DRL systems, we have determined that Toyota runs a pulsing system where the voltage supplied is roughly 10V-12V but pulses on and off very fast which causes an LED lamp, that is sensitive to power, to light up and shut off quickly. This only works with older model lamps like incandescent or halogen as it will never allow the burning filament, of a factory bulb, to light up to full intensity or shut off completely. The pulsing signal keeps the bulb in a dim state. We now have a solution for you to allow you to run aftermarket LED headlights!
JDM Astar offers a decoder module that is actually designed for CANBUS but will also bypass voltage changes that pulse on DRL systems shared with high beam headlamps.
How does the decoder work?
Our decoder features a built-in capacitor. A capacitor will hold a small amount of charge that will allow the current supplied to the headlight bulb to be steady thus preventing the pulsing voltage from having any effect on the diodes of the LED lamp. Since LEDs are very sensitive to power, a pulsing voltage will also cause the diodes to flicker at the same rate that it’s pulsing. A capacitor will also simulate a much larger amperage which will also take care of a lamp out indicator that is either triggered by the vehicles circuit, or in some cases, a CANBUS system.
If your Toyota happens to have a high beam lamp and DRL running on the same bulb and circuit then make sure you pick up a decoder harness from JDM ASTAR. They are plug & play and will save you a headache, as well as a traffic stop citation. If you ever have any questions or need guidance, contact us. Our friendly and knowledgeable representatives will be glad to assist you on resolving flickering issues on your Toyota and remember….
“LED JDM ASTAR light your way on the road!”
-JDM ASTAR Team