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seeking confirmation re: led tails w/ rear fog on 2012 w/ xenon

S

slush.puppie

Ready to race!
I have read through so my posts my brains is bleeding...

I have a 2012 gti w/ nav (xenon & led drls). I have oem vw led tail lights WITH REAR FOG, with adapters on a boat or plane from Germany right now. I have a euro switch installed, with the parking light trigger wire installed (from switch pin #3 to black cecm pin #19).

For the rear fog light to work, it is my understanding that I need to do the following:
* run trigger wire from switch pin #7 to black cecm pin# 17
* move wire from black cecm pin #28 to brown cecm pin #47
* move wire from brown cecm pin #47 to black cecm pin #28
* vcds coding under 09 central electronics, byte 18, change to either "04" or "21" (from what I've read, not sure exactly which one...)

Can anyone confirm or deny that what I have laid out above is correct? Thank you a million times over, in advance! :)
 
B

Buckshot

Passed Driver's Ed
That is correct from what I've read. I've spent hours trying to figure out this situation. My tail lights arrived yesterday, and I'm going to install them this weekend (hopefully today). I'll post back here about my (hopeful) success after I do it.
 
zVp

zVp

Go Kart Champion
I think "21" is without rear fog, so I think the right one is "04" for your combination. However, try both just in case.

I tried "21" on a Golf R with rear fogs, but it still gave an error about the reverse light.
 
S

slush.puppie

Ready to race!
Buckshot said:
That is correct from what I've read. I've spent hours trying to figure out this situation. My tail lights arrived yesterday, and I'm going to install them this weekend (hopefully today). I'll post back here about my (hopeful) success after I do it.
Click to expand...

thanks! I'll have to mail you a beer! :)
 
S

slush.puppie

Ready to race!
zVp said:
I think "21" is without rear fog, so I think the right one is "04" for your combination. However, try both just in case.

I tried "21" on a Golf R with rear fogs, but it still gave an error about the reverse light.
Click to expand...

was that with the cecm wire swap? thanks for the input. i own a vcds, so trying a few codes isn't a big deal, just want to start out heading in the right direction.
 
J

jbgtied

Passed Driver's Ed
That's right about the 04, but also you need to change it to ROW coding stands for rest of world. I believe.


slush.puppie said:
I have read through so my posts my brains is bleeding...

I have a 2012 gti w/ nav (xenon & led drls). I have oem vw led tail lights WITH REAR FOG, with adapters on a boat or plane from Germany right now. I have a euro switch installed, with the parking light trigger wire installed (from switch pin #3 to black cecm pin #19).

For the rear fog light to work, it is my understanding that I need to do the following:
* run trigger wire from switch pin #7 to black cecm pin# 17
* move wire from black cecm pin #28 to brown cecm pin #47
* move wire from brown cecm pin #47 to black cecm pin #28
* vcds coding under 09 central electronics, byte 18, change to either "04" or "21" (from what I've read, not sure exactly which one...)

Can anyone confirm or deny that what I have laid out above is correct? Thank you a million times over, in advance! :)
Click to expand...
 
S

slush.puppie

Ready to race!
jbgtied said:
That's right about the 04, but also you need to change it to ROW coding stands for rest of world. I believe.
Click to expand...

I'm actually already in rest of world coding I believe. I changed that so that I could get my led drls to dim when the front turn signals come on. I think it was under... instruments (17?)
 
B

Buckshot

Passed Driver's Ed
I just "finished" this project and did everything as stated in the original post in terms of the wiring. As far as the coding is concerned, to enable RoW, I went to byte 18 and there was a drop down menu there. When I selected RoW, it automatically changed byte 18 to "04."

When I first hooked up the VCDS cable I had all sorts of weird fault codes in various places. (Steering column lock? No idea why that would be.) I cleared all of the fault codes, ran an auto scan, and everything came back perfect with no faults.

Everything functions as stock EXCEPT the rear fog simply doesn't do anything. Maybe there is some more coding needed to "activate" it -- I vaguely recall reading somewhere that there might be -- but I didn't feel like messing with it. It seems that when I turn the euro switch to the parking light indicator, the headlights turn on as normal. Turning the switch one notch further to the "headlights on" indicator seems to be the same thing. The front fog lights work fine (and the front fog indicator on the euro switch turns green when they're on), but the rear fog light indicator does nothing. It appears that the reverse light only lights up on the passenger side, which I believe is how it's supposed to work.

Any ideas what I screwed up? I don't care THAT much about having a working rear fog light as long as everything else works fine, but if it's something simple I'll fix it.
 
B

Buckshot

Passed Driver's Ed
Also, I should note that if you are working alone and really want to make this go quickly and minimize cursing, a nice LED headlamp helps a ton, and the proper wire terminal tools make life so much easier than screwing around with sewing needles. Plus it's an excuse to buy more tools! I got these:

http://www.ecstuning.com/Volkswagen-Golf_VI--2.0T/Tools/Electronic/ES11414/

I'm sure someone is aware of a cheaper and/or higher quality solution, but they did the trick for me.
 
S

slush.puppie

Ready to race!
Buckshot, did you try switching tow RoW coding under "07-Instruments" as well??
 
S

slush.puppie

Ready to race!
Buckshot said:
It seems that when I turn the euro switch to the parking light indicator, the headlights turn on as normal. Turning the switch one notch further to the "headlights on" indicator seems to be the same thing.
Click to expand...

did you run the trigger wire for the parking lights position? from pin #3?

Buckshot said:
It appears that the reverse light only lights up on the passenger side, which I believe is how it's supposed to work.
Click to expand...

yeah, that's expected, as you actually only have one reverse light now (right side)
 
B

Buckshot

Passed Driver's Ed
Success!

I changed the 17-Instruments coding to RoW and it did nothing for me that I could immediately tell other than change the units of measurement to kilometers, degrees celsius, etc. I also got a fault code in 09-Cent. Elec. for some reason. I can copy that fault code if anyone cares to see it. So I changed the coding for 17 back to USA, cleared the fault codes in 09 and did another auto scan to confirm that I had no faults.

However, slush.puppie's comments about the parking light wire made me realize that I had a fundamental misunderstanding about how the parking lights work. I had assumed that they were activated via coding and I didn't realize that you needed a second trigger wire to get those working. I never really researched it because I didn't have much interest in making the parking lights work. Because of this, I had also assumed, incorrectly, that there was only one open pin in the headlight switch.

So it turns out that I had shoved the trigger wire in pin #3 thinking it was the only open one and assuming it was pin #7. I moved the trigger wire from #3 to #7 and everything works perfectly with no faults.

So the bottom line is that to do this on an Autobahn or other 2012 GTI with LED DRLs, you have to do the following:

- Run the yellow trigger wire from pin #7 on the euro headlight switch to Black CECM pin #17
- Switch the wire in black cecm pin #28 to brown cecm pin #47
- Switch the wire from brown cecm pin #47 to black cecm pin #28
- Code byte 18 to 04, which is easily done in the newest version of the VCDS software by clicking on byte 18 and selecting "Rest of World" via the dropdown menu.

This will allow everything to work as it was from the factory (LED DRLs on all the time, everything at the correct brightness, etc.). I also noted that the inner tail lights turned off when the hatch was opened, so even that works correctly.

And now that I'm comfortable doing the wiring, I ordered another trigger wire from ebay so I can get the parking light feature working (even though I'll probably never use it).
 
S

slush.puppie

Ready to race!
Buckshot said:
Success!

I changed the 17-Instruments coding to RoW and it did nothing for me that I could immediately tell other than change the units of measurement to kilometers, degrees celsius, etc. I also got a fault code in 09-Cent. Elec. for some reason. I can copy that fault code if anyone cares to see it. So I changed the coding for 17 back to USA, cleared the fault codes in 09 and did another auto scan to confirm that I had no faults.

However, slush.puppie's comments about the parking light wire made me realize that I had a fundamental misunderstanding about how the parking lights work. I had assumed that they were activated via coding and I didn't realize that you needed a second trigger wire to get those working. I never really researched it because I didn't have much interest in making the parking lights work. Because of this, I had also assumed, incorrectly, that there was only one open pin in the headlight switch.

So it turns out that I had shoved the trigger wire in pin #3 thinking it was the only open one and assuming it was pin #7. I moved the trigger wire from #3 to #7 and everything works perfectly with no faults.

So the bottom line is that to do this on an Autobahn or other 2012 GTI with LED DRLs, you have to do the following:

- Run the yellow trigger wire from pin #7 on the euro headlight switch to Black CECM pin #17
- Switch the wire in black cecm pin #28 to brown cecm pin #47
- Switch the wire from brown cecm pin #47 to black cecm pin #28
- Code byte 18 to 04, which is easily done in the newest version of the VCDS software by clicking on byte 18 and selecting "Rest of World" via the dropdown menu.

This will allow everything to work as it was from the factory (LED DRLs on all the time, everything at the correct brightness, etc.). I also noted that the inner tail lights turned off when the hatch was opened, so even that works correctly.

And now that I'm comfortable doing the wiring, I ordered another trigger wire from ebay so I can get the parking light feature working (even though I'll probably never use it).
Click to expand...

that's awesome! super happy to hear you got it all working! especially since we have virtually the same setup. my tail lights just arrived in the USA, so they should be in my hands by weeks end.

just FYI, when you change the instruments setting, under 17, to RoW (yes, it does switch you all to metric and 24 clock, etc, but this can be changed quickly via mfd), one of the benefits is that if you then go into 09 central electronics and check/uncheck (I forget which) the box about making drls go off when blinker is on, then you'll get the LEDs to dim on the side that the blinker is on. holy run-on sentence, but anyhow, I think it looks cool like that.

the parking light trigger wire is worth doing by the way. it will allow you to show off your cool new tails without the headlights on. it will also allow fog lights on without headlights, which looks cool, but in cerain foggy conditions could possibly improve vision. lower light reflects less.
 
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