LED Bulbs, CANBus Error Codes & How To Fix Them
In this post, we’re bringing you an episode of ABD TV where we aim to answer all of those burning questions, clear up the confusions and leave you brimming with knowledge.
Today we are tackling the murky waters of LED bulbs, more specifically the hassles of the dreaded CANbus error codes.
So what do I mean with CANbus Error Codes?
Well more modern vehicles are all about sensors, warnings and messages. When something goes wrong on your car, you’ll often get some sort of notification of this on your dash. This could be a simple warning light illuminating, or an actual written message.
Your car is full of these sensors and they will monitor many many systems throughout your vehicle from fuel injection to brake pads to seat belts.
In the case of bulbs, your car will let you know when one of the exterior applications has failed. This checking/reporting is commonly referred to as a CANbus system.
Of course these error messages are very useful and a great addition to modern vehicles, so what’s the problem?
Aftermarket LED Bulbs causing Error Codes
The problem is with false positives created with aftermarket products such as LED bulbs.
The most common way a canbus system will check if a bulb is working or not is to measure the resistance on the circuit. Some vehicles measure the total circuit resistance, others check individual bulbs. But they are checking for the characteristics of a normal filament bulb.
One of the core selling points of an LED bulb is the lower power draw. Who doesn’t want an extra bit of fuel saving! Especially with the likes of caravans and motor-homes.
I won’t bore you with the physics here, but less power means there is more resistance (P=V²/R). Your vehicle CANbus system is therefore going to see something it’s not expecting and flag up the error message. In some cases it will even cut power to that circuit, meaning your perfectly good LED bulb fails to illuminate.
Fixing the Error Codes
There are 2 main ways to overcome this problem and I’m going to run through both of these below:
CANbus Compatible LED Bulbs
The first and most simple solution is to fit a CANbus compatible bulb.
Bulbs like the Twenty20 Cree LEDs and some of the Ring Premium range have additional resistors built into them to adjust the characteristics of the bulb. This brings them closer to the parameters that your car is looking for.
As these are a direct replacement for your existing bulbs, these would always be our first recommendation of what to try.
In 95% of cases, this will be enough to overcome the issue. However some vehicles can be particularly fussy and they still throw up an error.
The issue is with the amount of resistance that would be needed for it to match a filament bulb. It would simply be too big and be too hot. The heat from a resistor would cause it to fail almost instantly.
Therefore the manufacturers can only try and get as close as they can and hope it falls within the required levels.
In cases where you simply have a super fussy vehicle, and even CANbus LED bulbs don’t cut it, we have to move onto our second option and add the resistance another way.
Resistor Kits for LED Bulbs
This is where resistor kits like this one from Osram come in.
This might sound like it’s getting complex but it’s actually very straight forward. You can see how this is done in the video at the top of the page. But the general concept is as follows:
A typical bulb holder that you would have in your car will have 2 wires going to it to supply the power. One for the positive and one for the negative. It’s not important in this case to know which is which, just that you have the correct 2 wires for your LED bulb.
On our resistor, conveniently enough, we also have 2 wires.
Simply use the supplied scotch locks to splice together one leg of the resistor to one bulb holder wire, and the other leg to the other. This is called connecting in parallel.
Once done, this adjusts the resistance to the correct amount without it impacting on the bulb itself.
And that’s it, simple.
Now you are an expert on LED bulbs and canbus issues. Remember, if you have a modern car with a CANbus system, first try a CANbus compatible bulb. If that doesn’t work, break out the resistors and you’ll be up and running in no time.
If you have any questions on this, feel free to ask them in the comments below.
Also if you have any other general product questions you’d like to see us cover in a future ABD TV episode, please send them in either via our social media accounts or via email.
Related Information
- Overview
- Aftermarket LED Legalities
- LED CANBus Errors
- LED Headlights
- OEM LED Units
Author: ABD.co.uk
Hi there I’ve just bought some LeD bulbs from you I have put the indicator ones in and they flash fine but on the dash the indicator signal flashes fast and the sound is fast but the indicators themselves normal speed what do I need to do to sort this thanks
hi, my son has a 2014 vw polo, he has fitted dynamic indicators which work with ignition on but when the engine is running he gets 3 flahes then they cut out. would the resistors shown work to cure this problem?
I tried installing H11 Twenty20 Cree LED 12V Canbus Foglight Bulbs to my For Transit Connect but I have CANBUS issues. Bulb flashes 4 times then stays off. I installed a 55w resistor across each bulb connection and same error. Bulb flashes 4 times then stays off.
If you have resistors on both bulbs it’d probably indicate your vehicle’s CANBus system is just hyper-sensitive.
Those bulbs have resistors already built in so if additional resistors aren’t working – it’s usually down to the vehicle.
You’d be better off plugging in an OBD-II device and just turn off the part of the system that checks the headlights.
Hi There. I have installed 2 new LED bulbs, brake light and indicator lights, on either side of my car. However, they are both connected with one wire. They are both 21w bulbs but connected to the same wire. This is on my 2015 Vauxhall Corsa. Would I still be able to install a 21w resistor to this one wire for both bulbs or would i need to double it so maybe go for one nearest to 42w? let me know!
hey what’s up? thanks for the above info; very useful. I’ve installed the H7 led bulbs about a year ago and now the passenger side low beam flickers. What do I do to correct it?
If it’s just one particular bulb it could be that the heat finally got to it. LEDs are quite sensitive to heat and most headlamps are designed to withstand, not dissipate heat, as a result the LEDs tend to get quite hot and generally start to die after a few months, flicker, dim or outright go out. So if it was fine the whole time and it’s suddenly just that one bulb, it’s like the LED is starting to die
Hi, I’m confused with what size canbus resistor’s should be fitted to. DRL 21w/5w led , thanks, Les
Hi Leslie,
If you know which filament is presenting the CANBus error then you would get the resistor that matches the wattage.
For example, if it’s the 5W part of the bulb giving an error then the 5W resistor will suffice.
A safer method would be to buy the 21W as this should cover both filaments.
With a combination bulb (stop and tail in one socket do you need a separate resistor on both aspects of the bulb?
Why do led bulbs flash when I fit them in my Saab 9-3 2008 and the ignition is turned off,weather it’s a indicator or a main beam bulb they all do this, how can I solve this problem.
The ideal,is to be able to swap out the old style flasher unit and replace it with an electronic unit. Unfortunately car manufacturers are fitted with blinders and just refuse to do it, even in the 2020, just to save a few cents,although with modern parts manufacturing I would doubt that there is any cost difference.
Not to be unfair, there are a few sensible Car makers who do fit electronic units plus LED bulbs, cynically though, they make their Led bulbs as an integral unit ,hence no easy bulb swap, large cost for replacement. Definitely not customer friendly, its all about the bottom line.
The most important thing Ohm resistance number didn’t mentioned ???
I’ve put in LED dipped bulbs from Twenty20 into my 2010 Focus, and the main beam dashboard blue light now doesn’t show. Can this be fixed by resistors?
Hello I have some aftermarket led headlights. Not sure how long this is going on but I know they’ve all worked previously. The main headlights work, then there is 2 outter led rings as well as 3 led lights on each side. One side the rings work and the other side only the 3 lights work. I’ve check all the connections I could locate and peeled off more of the wire to expose the wires better for the little blue clamps. I’m out of ideas if you know what else I could try please let me know.
Hi there
I have a BMW 3 series (13 plate) and have canbus bulbs but still have the error on the dash for all lights (parking lights low beam etc) is there a way of removing this using a software?
Hi, Just bought the 380 Twenty20 Impact Cree Canbus Bulb 12V P21/5W (Red) for my BMW R1200RT (2011) which you say are a direct replacement. The first thing to note is the lugs are not the same in relation to fit. The ones I bought from yourself are offset in height. I know have a tail light bulb warning on my dash to say that somethings wrong yet they both seem to be working.
I have a 2019 Jeep Renegade.I replaced all the front bulbs, headlights, driving and fog lights with leds and also put led turn signals on the side indicators. There were non at all. I had all the canbus issues and put in aftermarket harnesses with resistors. The only bulbs I didn’t change were the front turn signals, the side markets are tied into them with the harness. After this everything was fine then it started indicating running and parking light error all of a sudden now. Was fine before. What could be the issue now?
Hi I want to fit 4 spotlights wat do I have to do to over come the bcm problem
Hi there, i put koyonso Led hb3 9005 120w in my toyota auris hybrid 2011 and they not turn☹️what can i do?please
Hi. I have a problem with my 5-bulb DRL unit. They operate fine when the headlights are off – but when I turn on the main beam, one side remains bright whilst the other turns off. Is this a replacement model issue or a resistance issue that I can resolve without replacement? Thanks for your help
Ok so fitted resistors and have still got error on one fog light and one dipped beam but the rest are fine, any ideas or help please?
Hi there please help if you can I replaced my daytime running lights for led error free bulbs going great until last wk offside started flickering put it into drivers side still flickered so ordered replacement thinking it was faulty.a week has gone by and the offside bulb has dimmed any ideas why would be appreciated drivers side no problem at all tia
Hi I have a vw caddy mk4
Have changed the day time running lights to Osram LEDS
Which has put a light bulb on in the dash
The bulb holder has 3 black wires to it how do determine which 2 to connect resistor to.
Thank you
I need help with my 2013 chevy silverado I put led head light’s on it put my airbags light’s on what I need to do
I bought some Roylux LED headlight bulbs for my 2005 Toyota Tundra 4-door. the bulds work well, but my foglights will not come on at all. When i switch them on, the headlight brights come on. When i try to dim the headlights, they stay on high beam until i switch off the foglights. Do you know a fix?
On my car it detects a blown bulb when the LED unit is connected but switched OFF so not presenting a 26W or so load, when the LED is ON the error disapears as it is drawing similar power to incandescent bulb. The detection is done by tying the bulb feed to a logic high via a resistor of unknown value and a diode and if a bulb filament is present and intact it will pull down that logic high to a logic low and be detected as present and functioning when bulb is not in use, before you need the light… In this case the shunt resistor value should not need to present a 6R or so load to compensate for low LED power but to simply pull the OFF conditions logic high down to logic low. I will have to put a variable resistor in parallel or in place of the reversing light LED and put ignition ON but not select the reverse gear and find out what the highest value I can get away with to silence the LED OFF BCM detection of blown or missing bulb. Then calculate what power will be dissipated when the full 14.4V is applied when reverse gear is selected and source a fixed resistor of nearest preferred value below the max I can get away with.
Hi, I have a Jeep Compass 2014 and have replaced my low beam headlights with H11 as described. First I installed regular leds supposedly compatible with car H7-H11-9005-9006 Auto Headlights kit Led Light 18000lm 80w. Changed to other model Headlights kit Led 16000lm Auto Csp H1 H7 H11 9005 9006 9012 w/Canbus 50w/ea. The problem is that it does not matter which led lights are installed with Canbus or not the headlights start to blink on and off. One on passenger side starts first then jumps to driver side then in unison. Like Xmas lights. Any suggestions? Would greatly appreciate some guidance. Thanks and merry Xmas!
Hi my car failed mot on Friday the Charles Street Quick fit as he said led bulbs no no I had them fitted by a professional in Nottingham he did no put on the paper that he failed because of led bulb) fitment so he said he will take them out and all the fittings and whole set up then proceeded to install two bulbs from the shop that are very dim I told him the 2014 zafira has leveling for up and down and he said again if he don’t change out the led system and fit his shop bulbs then he won’t pass the car mot I am very cheesed off he red the mot declaration but did not read further on about the leveling sistem that the zafira has. What can I do about the service I was given having to pay an extra 40 pounds on top of the mot for his bulb fitment and time cost to remove my complete units and fit his bulbs that are very dim. Can you please help thank you kennith muir
DONT USE QUICK FIT, HALFORDS, Hi Q OR ANY OF THESE FIRMS!! This lot will find faults that are not there, charge you exorbitant prices for a £5.00 bulb, then charge for removing whole headlight unit to install the bulbs when access is there already with the headlight fitted!!
They are rip off merchants!!
Use a local garage… They will have trained staff rather than staff who meet Quick Fits standards, and their standards are very low!!
Good morning, I have a 2006 Volvo S60 I bought it a year and a half ago and had to replace the driver’s side low beam bulb4 times already. I am careful not to touch the bulb as I know that oils from your skin will cause them to over heat. Is there a solution to the problem? Is this a Canbus wiring issue?
Good afternoon, Can you tell me if the 2014 Smart fourtwo would accept aftermarket sidelight LED’s without causing Canbus issues. Many thanks.
So I bought some LED headlight bulbs for my 2008 scion xb and when I replaced them I now have 2 dash lights on. The traction control and my check engine light is on. Anyone know why?
So i have a 2018 silverado ltz and i have the tri-projection led’s an they came with resistors already wired in the headlights are fine the drl/turn signal hyoer flashes after 3 normal flashes an gives turn signal lamp out warning, none of the lights are bulbs they are boards can i install canbus decoder to cancel warning msg?
Hi I have replaced the interior lights in my wife’s golf with LED bulbs, but they do no go out after 10 seconds or so like the old bulbs did. They do go out when you lock the car, but not while you get in and drive off. Any tips> Michael
Bulbs don’t ask for power, the vehicle gives it to them.
Depending on the situation, there might be just enough charge going to the bulbs to light them up.
A simple fix would be to try a different range of bulbs or fit a resistor kit to the wiring behind the bulb.
Hello i have a volvo s40 mr2 2004. I install samsung mover f3s h7 and the low beam failure still appear. I read at some forums that many have this problem. what i should do? The lights works fine but i have that error on my panel. I think the square box that they have is already canseler or not? Any help please? Maybe to do everything led it will solve the problem or not?
What will be the best salaution to not to let load resistor to get so hot anything I can do to secure it from burning anything
I have just fitted Ring Premium LED bulbs (RW501CBLED 12v W5W 501 LED) to sidelights of Ford Ka 1.2 2001 as wanted to increase visibility of daylight running lights (sidelights). They were fitted to replace other LED side lamps that worked but brought up dashboard warning (lamps out). The Ring are bulbs advertised as suitable for my car and CANBUS. The bulbs do not work at all and warning light remains. I have replaced the old filament bulbs. Any ideas before I send them back?
Hi John,
Unfortunately nothing is ever guaranteed with aftermarket LED’s and CANBus systems.
Whilst a bulb is CANBus compatible, it won’t be fool proof and may still cause errors.
This isn’t specific to all Ford KA’s though, we’ve found it’s specific to the vehicle.
The best options would be to either try a different range of bulbs or to fit a resistor.
i’ve changed the headlight for xenon one on a vito, i cannot get them programmed to work at mercedes so thinking of doing via a relay per element this brings on a bulb failure as the power for the relay is approx 1.5w, is it just as simple as fitting a approx 5o watt resistor?
Hi I have a Mercedes Vito. My small car trailer lights are not a problem, but with a caravan which has a total of eight extra bulbs. 2 front marker lights 2 side marker lights 2 number plate lights and two rear side lights. When the lights are turned on they go off and on several times then go offpermanently . Can you advise. Regards Michael.
You supplied me with campus bulbs for my 12 Skoda yeti 1.6 diesel my warning light is still showing check left brake light plus registration plate light even though they are still working is there a special way of putting them in and is common to happen on this particular model car
Hi Henry,
Unfortunately, it’s vehicle specific and results can differ between vehicles from the same line.
The best way to remove warning errors is to fit an LED resistor kit.
581 Twenty20 Impact Cree LED Canbus Amber Bulb 12V PY21W Order ~867827
I have fitted these to the rear indicators to my Ford Kuga 2015 and if I switch on either right or left indicator the indicators flash much quicker as if a bulb was not working, I do not have any error warnings, if I put the hazards ie all 4 indicators they flash normally what is wrong please.
Thanks Richard
Hi Richard, If you experience hyper-flashing then it’s worth swapping what you’ve purchased for some LED’s designed to prevent hyper-flashing.
I would recommend the 581 HF0 LED’s by Twenty20.
They are designed to prevent against quickly flashing LED’s and are incredibly bright compared to a standard bulb.
Hi, is there anything on the market at 70w for 24v truck H7 headlight bulb
My Drl’s power on while the car is off for a few seconds periodically… I have a 2020 Camry and I purchased a set of aftermarket drl/fog lights for amazon
Would I need a resistor for each bulb or can I get 1 for the whole system?
I have replaced the 36mm filament number plate festoon lamps in my Saab 95 Aero (new generation) of 2011 for Osram LED C5W cool white lamps (SV8. 36mm)
The lamps are good but the Saab throws up an error on the dash of lamp failure.
I have then purchased the Osramr 5w LEDriving CANBUS Control unit.
I have wired these in the system and the error message is still there.
However, if I add only a 5w filament lamp into the circuit (no other devices attached) the message disappears and obviously reports that all is ok.
Why am I getting this, when the Osram 2x 5w canbus resistors are placed in the circuit the error is still presented on the dash. What is going on!
Regards Philip
Hi, My sequential leds work fine with ignition on then start engine running lights stay on sequentials stop
Thanks for the information above. As you state in your video one of the reasons for using LED bulbs is to save power. However in cases where you have to connect a parallel resistor to keep the CANbus system happy there will be no power savings. The LED bulb and resistor in parallel will draw more or less the same current as a standard filament bulb. This must be the case if the CANbus system is to ‘see’ the expected resistance as a normal bulb since R=V/I. The voltage V is standard battery voltage.
Hi Joseph, You are correct.
If a driver only wanted the LED bulbs to reduce the power consumption then a resistor would be pointless.
The majority of drivers choose LED’s for the light output, longevity and reliability and fitting a resistor will not affect any of those. Most drivers will not consider power consumption unless there is something wrong with their vehicle such as a faulty alternator or battery.
Most modern vehicles can cope with large amounts of power usage and older vehicles very rarely have any sort of CANBus system so a resistor wouldn’t be needed.
So I take it you have to use a resistor kit for every bulb you’ve changed to led.
Hi Gerrard,
No. You would usually only fit a resistor kit to bulbs that display a CANBus error.
You wouldn’t need a resistor for every LED bulb.
Good afternoon, I have 2 Osram H7 LED bulb and I have an error on dashboard. Can you tell me please what Canbus is beter to use between Osram LEDCBCTRL 103 and Philips H7 Canbus. I know at Osram canbus I will have to change the conector. Thank you!
can you still use the led light bulbs and just ignore the censor saying the light it still out?
Hi Dylan,
A warning light should not have any detrimental affect on your vehicle’s performance.
I fitted your CANbus LED stop/tail light bulbs to my 1993 Yamaha GTS 1000 and although it didn’t have a CANbus system as we know it today it did have an early ABS system. The bulbs really upset the ABS system which created error codes. It was only after fitting Osram resistors that the problem was resolved. I have to say that the bulbs give a great light and hope they stop me getting squished from behind.
The reason for the errors in an apparently unrelated system is incandescent bulbs act as transmission line termination resistors and shunt Radio Frequency Interference to the ground and stop unterminated wires acting as aerials picking up interference and coupling it to other sensors wires within the loom. I had that when replacing stop incandescent bulbs with non-CANBUS friendly LED’s which all ran via a single wire and caused many misc codes, the solution was to fit a 220R 0.5W resistor in parallel with the high brake LED array… just because it was the most accessible place to solder a resistor. HTH some other reader in the future.
Great article! Looking to use 10W DRL leds. Am I able to use 21W osram resistors? Short of the long is, do you have to use the same watt resistor as the led’s or can you use higher resistors?
Thanks in advance
Hello, I have yellow (ish) halogen DRL bulbs on my vauxhall insignia and want to change them for led bulbs and have no error messages / bulb out on the dash. Which rating of osram resistor kit would be suitable? Thanks.
Hi I have a Boxster 987 2005, in the rear lights I have the following bulbs
tail/ stop, tail/fog , tail light only plus indicator and reverse, I purchased 20 twenty led’s from yourself but all throwing up errors, could you tell me which resistors I need to order from your site for the following bulbs I ordered
the bulbs I purchased were
1 x 380 stop/tail, 581 rear indicator, 566 rear fog, 382 reversing – need to order another pair of 380’s as thought there were only 2 tail