Using LED with a CAN Bus System

You have heard once before, and you will hear it again.  “What is a CAN bus system?”  A CAN bus is a “Controller Area Network” vehicle bus which interconnects components inside a vehicle.  A CAN bus is like an on board diagnostics system that runs upon turning the ignition and while the vehicle’s operating.  The system also monitors your vehicles applications such as lighting.  A CAN Bus system is equipped with the vehicle to alert a driver of a problem with the normal functionality of an application or their vehicle.  A lot of 3rd parties indicate that it only monitors your lighting applications, which they do, but they also monitor everything else that may be considered a safety hazard should the part, component, or application fail or begin to malfunction in a manner that is considered abnormal.  A CAN bus system can be frustrating or cause malfunctions but they are an essential system to have on your vehicle.  We created this article to help you understand how to make your lamps function properly without a worry of a dreadful lamp out indicator or flicker.


The main reason why a CAN bus system cannot detect an LED bulb is due to the power draw (current) of the lamp application or resistance change.  By upgrading your lighting application, whether interior or exterior, you are decreasing the power draw substantially.  It may vary between vehicles, but a CAN bus system (or any similar system) is designed to function a certain amount of power (current), voltage, resistance or amperage of the different applications on the vehicle including lights and by installing an LED bulb, it may recognize the bulb as a fault or opened circuit.(burnt out bulb)  These type of systems are not designed to work with the current of an LED replacement.  They will not be able to distinguish the difference between an actual ‘burnt out’ halogen bulb, and a new upgraded LED so an error code or lamp out indicator may be triggered.  Some cases it will cut power to the application which will result in a sudden flicker then shutting off.  So how do you solve or avoid this malfunction?


The solution is very simple, for most vehicles.  JDM Astar offers “error-free” LED replacements in various sizes from 921 (T15), 1156 bayonet size, and all the way to bulb sizes for headlamps.  They come equipped with built-in decoders.  A decoder (or anti-flicker harness) is a module that is designed to counter or fix CAN bus related problems and they feature a built-in capacitor to keep the LED’s charged (prevents flickering).  The decoder will also increase amperage which will allow the system to detect the lamp (prevents lamp out indicator).  There is also added resistance to allow the vehicle’s circuit normal functionality and ensure the LED’s are receiving proper current.

You can also take the simple route and add resistors which will allow the bulb to simulate a much larger current draw which for most cars will fix a problem triggered by the system.

Another great option is to use an “Error Free” LED which for the most part is designed for vehicles equipped with CAN bus.  With Error Free LED’s, they will feature resistors within the bulbs circuit to allow a larger current draw, however, this type of setup has its limitations on how much can be drawn.  There are certain makers and/or model vehicles that are programmed to detect a much larger current than what a CAN bus-ready LED bulb has to offer.  They may still trigger an error code so then the proper load must be applied to the vehicles circuit by wiring in a resistor.  You can do this by installing resistors to the ground and lead wires.  Resistors will draw out the difference in power to simulate the power draw of your halogen bulb.

If your vehicle is built with a CAN bus system, then don’t worry.  We have an arsenal of solutions waiting for you to resolve any minor issue with your vehicle’s CAN bus system and LED replacements.  If you run into a problem, we are here to help.  We can help you find the perfect LED replacement so that you will have an error-free experience.

-JDM Astar Team

Why is your LED lamp failing?

We have heard this issue before, and we believe that we can speak for every automotive LED sellers that they have come across a similar situation.  So, why is your LED bulb failing prematurely when it is supposed to last a lot longer than your factory halogen bulbs?  There may be several factors that could cause your LED bulb to fail prematurely, but the number one (and most common) reason is usually due to heat.

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When LED made its way into the automotive industry, there was not that many options available.  The overall light output just did not make sense for the investment and not to mention, it lacks the innovations we have today.  Now, LED has made its foot print in the automotive industry and is slowly climbing up the ladder to reach its peak in the automotive market. You may improve the light output of your vehicles application (like a backup light) at half the rate of power consumption with double the light output for less than what a traditional halogen or incandescent bulb would cost you.  (Now, you can really start getting the light output that you need and/or desire and save money while you are doing it. Who doesn’t like to save money?)

3030 Housing.jpg

Now that the brightness is up to par, heat generation is now the concern in the automotive industry for LED lighting.  We have learned that having a balance between light output and rate of heat dissipation will provide a long lifespan with your LED replacement bulbs.  Just like a computer part, LED has always had a threshold with heat.  LED is definitely an upgrade for any automotive vehicle, but it is susceptible to failure at high temperatures so having some type of cooling mechanism is always recommended.  We have also learned that there are other factors that play a role in the maintaining temperature of the LEDs.  We know that drive power will increase light output but will also spike the heat generated from the diodes.  Limited or small housing assemblies may also cause your bulb to heat up to a temperature higher than it can handle and cause the bulb to show symptoms of failure.  For example, if you install a standard low light output LED bulb to side mirror application, it will definitely provide brighter results, but if the bulb is a high power LED with a high lumen rating, then it may not be the best idea.  The fact that the housing is very limited, in space, it builds up the heat faster and does not allow any cooling.  This, combined with the amount of heat generated, may cause your lamp to begin to fail prematurely.

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Just like your car engine, your LED bulbs have a threshold.  If you put a super charger, or turbo into your engine, it will work harder, and faster, but will also put wear on the internal parts of the car so it will cause the engine to not last as long as it was intended.  You will then have to service the engine.  Like your engine, LED also has a limit or threshold as to how much it can handle.  As long as there is a balance between heat dissipation versus heat generated then you will have a long lasting LED bulb.

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Next time you are in the market to replace a bulb on your car, you should always take into consideration how your housing is designed, light output (wattage will also determine heat generated), and the LED housing. (Does it have an aluminum body to radiate heat from the light emitting diodes?)


Here at JDM ASTAR, we do not believe in limits.  Every day, we are learning new ways to redesigning our products, or integrate other parts like an aluminum boards to improve efficiency, and reliability.  We believe in pushing the threshold of automotive LED.  We are always trying to push our products to the limit and looking for new ways to remove the barrier that heat has created for everybody in the automotive LED lighting industry.


So, if you need to replace a factory, or a failed LED bulb, do not just aim for the brightest, but aim more for an option that will provide a balance between power, and reliability. . . . An option that only JDM ASTAR can deliver so that we may continue to light your way on the road. . . .




What is a CK/SRCK socket?

A CK/SRCK is like the traditional sockets you see in most Japanese, and American vehicles except the ground terminals are located on the same side of the socket.  If the ground terminals are located on the opposite side of the socket, then it more then likely is a standard socket.  We still encourage you to test the sockets using a multimeter.  To identify the ground positions.

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Standard Socket

What will happen if a standard LED bulb is used for a CK socket?

Only one level of brightness(intensity) will light up, and when the other application is activated, it will cause a short on the circuit.

How to distinguish between a  CK socket and a standard socket?

From our experiences, most TOYOTA vehicles front turn signal sockets are a CK type.  Sometimes, you can even see there are two terminals connected directly, which means they are the ground terminals.  You may also identify the ground terminal location from the wires on the back of the socket.  A test is still required, using a multimeter, in order to confirm the type. Also your original bulb will tell you if it is a CK or standard, most CK bulbs will say SRCK on the bulb base.

Why do I have a standard halogen bulb, but a CK socket?

The ground pins of halogen bulbs are not shared. The ground pins of LED bulbs are connected on the circuit board inside the LED bulb. The circuit board is necessary to help maintain the temperature of LED which will provide stability, and a long lifespan.

How to solve Turn Signal Light Hyper-Flash

Did you just purchase LED bulbs for your turn signals, installed them and now is wondering why it is flashing really fast?

Well the reason is LED lights draw about 5W of power, which is much less than that of a halogen bulb(27W~30W).  An error code or hyper-flashing is a malfunction that will come up to notify the driver when vehicle detects a change in the power draw.  The vehicle is recognizing the upgraded LED bulb as a faulty (burned) halogen bulb due to the low power consumption

Below are the solutions we recommend that will fix any error code, hyper flashing, flickering issues that you may run into.

SOLUTION ONE: Plug n Play Resistors

3157-5 installation


We have made plug n play resistors for different socket types, ex. 7440 7443 3157 3156 etc. These plug n play resistors are very convenient due to the fact that there is not splicing or tapping of any of your OEM wiring. This will be the simplest solution to solve your hyper flashing issue.

PLEASE NOTE: Resistors will get hot, when installing resistors please keep them away from any plastic or wires.

The power of load resistors is 24W@12V  24W+5W=29W, nearly the same power as a halogen bulb




This LED flasher relay will replace your original flasher relay. Here at JDM ASTAR we have made this product for customer who do not want any resistors near any wiring or plastic, so this would be the best alternative for those customers. With this relay it is a direct replacement for certain vehicle makes such as Honda, Volkswagen, BMW, Mercedes-Benz, AUDI, etc.

The LED flasher relay is very similar to the resistor, it regulates the power and tricks the vehicles system to prevent the hyper flashing with the LED bulbs.



SOLUTION THREE: Universal Load Resistors

50W 6ohm load resistor

These Universal 50w 6ohm resistors will work for any vehicle to fix error codes and hyper flashing. With the universal resistors tapping or splicing is required. To install these resistors you would need wire taps. Most people will tap the rear turn signal wires instead of the front due to weather conditions or road conditions that may affect the resistors.

The universal resistors will help prevent any flickering issues, hyper flashing, or error codes by regulating the power draw to the circuit. These will work with any vehicle that may need it, installing these may be a tad bit difficult on some vehicles depending on how much space they may have.

To install these resistors you would need to tap the ground wire and the turn signal wire, for some vehicle this would be really simple to find since the rear turn signal has 2 wires. For the vehicles that have more than 2 wires in the rear turn signal you would need to use a test light and test which wire is the turn signal wire. After finding the wires and tapping them, you would need to mount these resistors away from any plastic or wires due to the resistors getting extremely hot and may cause damage to the vehicle.


To purchase any of these resistors please visit our website

LED bulbs not lighting up?

We have all been there, we purchase bulbs from online sellers, and once we get them in we are full of joy and excitement and ready to install. Some of us have installed some bulbs and find out that they don’t turn on, so we start assuming that they are defective and start having a huge disappointment. Now before you go and complain to the seller or give negative feedbacks, here are a couple of ways to troubleshoot your “defective” bulb.


STEP ONE: Rotate the bulb 180 degrees.

This step is the simplest way to figure out if your bulb is defective or not. You simply just rotate the bulb 180 degrees to see if the bulb will light up.

Now you may ask why it is necessary to do this, well most LED bulbs are polarity sensitive, which means they will only work when the positive pin matches up with the positive side of the socket/plug you are putting the bulb into.



STEP TWO: Bending the pins

This step is also an easy way to figure out if your bulb is defective. Bending or moving the pins more outward will help ensure proper connection with the socket. Sometime the bulbs base will be too narrow to the point where it will not make any contact at all, with a little modification with the pins on the bulb, you will have a nice snug fit and good contact to ensure that the bulb works perfectly fine.

T10 5050 wire adjustment

STEP THREE: Put back your original bulbs

If both steps did not work out for you, then you will move on to this step. It is another simple solution, put back your original bulb in the socket to see if it lights up. If the original bulbs light up then you can come to the conclusion that you have received a defective bulb, if the original bulbs do not light up then you would need to check your fuses or check the wires to see if there is any power going through the wire. Checking your fuses will be explained in the next step.

STEP FOUR: Checking Fuses

Checking fuses is always a solution to a lot of wiring or power issues that you may have. When the first three steps are not helping, this option would be sure to help you figure out why your bulb is not lighting up.

There are multiple fuses for almost everything in your vehicle, if your bulb is not lighting up this may be the reason why, you may have a blown fuse. To check which fuse you would need to pull or check, you would need to go to your owner’s manual and find the fuse box locations. Once you have found the location of the fuse box, this is where you can see which fuse controls what. Then once you have found the fuse that you are looking for, pull it and then you will be able to see if it is blown or not. If it is blown, replace it with the same amp fuse(NEVER use a high amp fuse) and test the bulb again.