DIY: LED license light error permanent removal

[ziggyboy]

For those who have attempted to replace the license plate globes with LED's, you'll know that majority of "non-CANBUS" ones do not work, and even those marked as error-free do not necessarily work all the time. The reason for this is that the car's computer checks the current/power flowing through the license lights, if it is below a certain threshold then you'll see a warning on your MFD which can get quite annoying.

My solution is to permanently solder a resistor onto the casing. It is essentially the same thing as buying load resistor kits but at a much cheaper price. I bought each resistor for $0.40 each. This entire solution cost me less than $1!





First things first, before I tell you what resistor to buy it is important to understand the basic physics of what you're about to do.

The stock T10 globe is 5W.

Each 5050 LED consume about 0.2W (assuming 12V power source), so the 9 SMD 5050 LED globe like the one I used above may draw up to 1.8W (9 x 0.2).

5W - 1.8W = 3.2W difference from the stock globe! Now we would like to look for a resistor to fill that 3.2W void. We know pretty damn sure that the computer isn't checking for exactly 5W as bulbs will not always draw the exact advertised watts. I made a wild guess that maybe it is checking 50%, or 2.5W.

I selected a 56 ohm resistor (5W capacity) which would draw about 2.57W. If you must know the calculations...

12V / 56 ohms = 0.21429A
12V x 0.21429A = 2.57148W

Ok, so 2.57W resistor + 1.8W LED globe = 4.37W total power!

I tried the resistors without any globes and saw no MFD error, which means the threshold is below 2.57W. That's good. This means I can put in anywhere from 1 to 12 5050 SMD comfortably, but it is normally safe to exceed the 5W. I'd say maybe up to 6W or so is safe? That gives us up to 18 SMD's. Not sure if you'd want them that bright anyway.... if so, just pick a resistor with a higher resistance and you'll be able to put higher capacity LED's.

Resistors do not have polarities so it does not matter which end gets solded where. Make sure there is enough clearance from the resistor to any other part to avoid it melting any of the interior components.

The resistor draws about 2.57W and I chose a resistor with a 5W capacity to make sure I have accounted for fluctuations in the power source. Car batteries are not precisely 12V. Some sources claim an average of 12.6V or even as high as 14V!!! It is wise to pick 5W capacity versus 3W for this reason. Plus your resistors will last longer if you keep the running power at around 50% of the rated maximum capacity.

Also remember that by soldering the resistor, you're restricting yourself to using LED's. DO NOT put regular 5W globes on them as it the computer might shut down that entire circuit thinking it is defective for drawing too much power. It is also a good idea to remove the resistors should you decide to sell the car as it is easy for future owners or non-electronics savvy mechanics to just replace them with regular globes!

Disclaimer: I am not responsible for any damage this may cause your car. Do this at your own risk. I have done electronics at university over a decade ago so I'm not exactly an expert on this, but after some brushing up, I am confident my calculations are correct!

Hope this helps anyone. Each resistor cost me $0.40!

[regina105]

thanks for sharing the info.

Will the resistor get very hot while the tag light is continuously lighted up?

Also, do you have any insight about the HID bulb out error for 2012 GLI? Is it the same principle as to the LED? I am thinking to drop a 25W or 50W load resistor across the wire to make the 35W HID kit uses 55W as the computer would recognize. What is your opinion on this?

[ziggyboy]

Again, I'd like to disclaim that while I've got theoretical electronics knowledge from university ages ago, I do not have much practical experience, so don't quote me on this. Others are free to contribute or correct me!

Will the resistor get very hot while the tag light is continuously lighted up?

Generally, yes resistors will get quite hot, but if you stick to half the rated maximum power, it shouldn't get as hot. In my example, I'm running a 5W resistor at 2.57W so I think that's pretty safe. I also checked the clearance above the license light housing and there's plenty in there. It's not like the resistor is next to other electronic parts.

Also, do you have any insight about the HID bulb out error for 2012 GLI? Is it the same principle as to the LED? I am thinking to drop a 25W or 50W load resistor across the wire to make the 35W HID kit uses 55W as the computer would recognize. What is your opinion on this?

Ok. I don't have experience with HID, but are you getting MFD errors because your headlights are only pulling 35W? In that case you could put in resistors easily to fix that. Buying the kits are your safest bet but if you want to save $$ then go DIY or if you're not comfortable with a soldering gun, ask someone to do it for you. I'm sure you'll find a friend or family member who's done a bit of it.

One warning about the kits though. Some of them are not safe in my opinion, especially those that are made in China. I was recently looking at 25W turn signal load resistors on eBay and calculated the power it was pulling at 12V and turns out to be 21W. That is way too close to the maximum capacity, and you'll easily go over 25W and potentially damage your circuit in the process. Another thing to remember is if you see a "25W resistor" advertised, this does not mean it's going to use 25W, that's just the maximum capacity. Ideally you should be running close to 50% of that (up to 70% is maybe OK).

Since you're working with higher watt devices than my 5W T10's, I would highly recommend running about 20-25W on a 50W resistor. My suggestion is 6 or 7 ohms (24W and 20.57W respectively). Where you're going to put the resistor is something I can't help you with. I'm not familiar with the headlight casing but it's better to screw them on metal.

[regina105]

I don't have a HID kit yet, but I have been looking in the forum and didnt see any 2012 GLI owner installed a HID yet, mostly people are saying that it is very picky on HID and seems not be able to light up the HID or getting MFD error. I don't know what causes the problem but my guess would be on the wattage issues. So, that make me think on dropping a load resistor across. I have both 25W 7 ohms and 50W 6 ohms.

If I use 25W 7 ohms resistor, for 12V input, the actual wattage would be 20.6W, getting close to the rated 25W, so no good?

If I use 50W 6 ohms resistor, for 12V input, the actual wattage would be 24W, is that better?

[ziggyboy]

I don't have a HID kit yet, but I have been looking in the forum and didnt see any 2012 GLI owner installed a HID yet, mostly people are saying that it is very picky on HID and seems not be able to light up the HID or getting MFD error. I don't know what causes the problem but my guess would be on the wattage issues. So, that make me think on dropping a load resistor across. I have both 25W 7 ohms and 50W 6 ohms.

If I use 25W 7 ohms resistor, for 12V input, the actual wattage would be 20.6W, getting close to the rated 25W, so no good?

If I use 50W 6 ohms resistor, for 12V input, the actual wattage would be 24W, is that better?

Since you've already got a 25W 7 ohms resistor, I suggest testing this with the HID kit first. If it fixes the problem, then go get yourself a 50W 7 ohm resistor. The increase in maximum capacity will pretty much ensure its survival for practically the entire life of the car. The closer you run resistors to capacity the more strain you put and hence shorten its lifespan.

Personally I'd go with the lower power consumption you can get away with, as that will mean less heat. I personally think 20.6W on a 50W resistor is sweet. Good luck!

[regina105]

I don't have 50W 7 ohms resistor, I only have the 50W in 6 ohms.

But I guess for 12V input, 7 ohms gives 20.6W and 6 ohms gives 24W. As for the resistor rated at 50W, 20.6W or 24W output doesn't make lots of difference, isn't it?

[ziggyboy]

I don't have 50W 7 ohms resistor, I only have the 50W in 6 ohms.

But I guess for 12V input, 7 ohms gives 20.6W and 6 ohms gives 24W. As for the resistor rated at 50W, 20.6W or 24W output doesn't make lots of difference, isn't it?

Well, 24W should be OK on a 50W resistor. It's still below 50% of capacity. It's just a personal preference to run at a lower power to reduce the most amount of heat that I can.

[regina105]

got it, thanks.

Any idea about the power rating for the stock DRL and the city light? I want to change into LED as well, just want to make sure it won't through bulb out error.

[ziggyboy]

got it, thanks.

Any idea about the power rating for the stock DRL and the city light? I want to change into LED as well, just want to make sure it won't through bulb out error.

City lights are same as license lights T10 5W. Afaik city lights are not monitored, just the DRL's, which use 1156 21W bulbs. Would suggest getting the DRL LED bulbs that don't throw errors. There are a few confirmed to work OK without the need for resistors. See the bulb thread. I personally use the 44 SMD one.

[frozze]

Nice work Ziggy! I'll see I can find someone to help me solder!

I bought these LEDs and they're probably the best one I've tried. The colour is very close to "OEM" bulbs that I've seen. They're really bright too!

http://www.v-leds.com/Interior-LED-B...viewsTabAnchor

You reckon the resistor that you recommended will work with these LEDs' specs?

Also, where did you get the resistors from??

Thanks!

[ziggyboy]

Nice work Ziggy! I'll see I can find someone to help me solder!

I bought these LEDs and they're probably the best one I've tried. The colour is very close to "OEM" bulbs that I've seen. They're really bright too!

http://www.v-leds.com/Interior-LED-B...viewsTabAnchor

You reckon the resistor that you recommended will work with these LEDs' specs?

Also, where did you get the resistors from??

Thanks!

Thanks!

According to the "specs" tab the current draw of those LED's are 2W. The resistor I'm using would be the most suitable, 2W + 2.57W = 4.57W total which is just under the 5W stock.

Let me know if you've got any questions. Got them from Jaycar There's a resistor section there. Just look for the exact same resistor in my pics.

I also wanted to make sure the temp wasn't too hot so after driving at night this week, I took out the casing and felt the resistor with my finger. They weren't burning like many people have said, and that was after having them switched on for about 2 hours! I really think running resistors at 50% capacity will keep them cooler and last longer.

[AndriyNYW]

can you send a link for resistors and i got 5050 5 leds

[SimpleStaple]

Or you can just buy CANBUS bulbs...

[AndriyNYW]

Or you can just buy CANBUS bulbs...

YEA I 4 SETS OF THEM CANBUS THEY STILL GIMME ERROR SCREW PAYING 10 OF EACH SET AND TRY other out if i can buy 1 pair or load resistors... GLI TO DIFFICULT to deal with . i cant even install HID on properly either error or burned ballast

[regina105]

YEA I 4 SETS OF THEM CANBUS THEY STILL GIMME ERROR SCREW PAYING 10 OF EACH SET AND TRY other out if i can buy 1 pair or load resistors... GLI TO DIFFICULT to deal with . i cant even install HID on properly either error or burned ballast

stay tuned with this thread for HID

http://forums.vwvortex.com/showthrea...tta-GLI-thread

[asusc]

Or you can just buy CANBUS bulbs...

Doesn't work for GLI. Still waiting on GLI specific error free license plate bulbs.

[blkmagic1]

The city lights are monitored. I swapped mine to 12w canbus leds I bought from ECS, and they threw a code. I put in some cheaper canbus leds, and error went away, lol. I got tired of the error for my plate lights, and just went back to bulb, got piaa extremes...

[ziggyboy]

can you send a link for resistors and i got 5050 5 leds

Your local electronics shop would have them. Alternatively, search 5w 56 ohm on eBay.

[ziggyboy]

Or you can just buy CANBUS bulbs...

Wasted 5 weeks ordering $30 worth of canbus bulbs that threw errors. That or 40c resistors?

[regina105]

what is the difference between cement resistor (the one you are using) and metal oxide film resistor?

I found there are many different kinds of resistors (cement box, metal oxide film, aluminum), but with the same spec. 5W 56 ohms. So, I wonder which one to choose? Are they the same?

[ziggyboy]

what is the difference between cement resistor (the one you are using) and metal oxide film resistor?

I found there are many different kinds of resistors (cement box, metal oxide film, aluminum), but with the same spec. 5W 56 ohms. So, I wonder which one to choose? Are they the same?

They function the exact same way, it's just the construction that's different. You can google the differences. Sorry can't be of much help, but I vaguely remember reading that ceramic cement and metal oxide resistors are durable and suitable for commercial use.