Notes on LED Tail / Rear Fog Install

[steelcurtain]

Dergolfgti - thanks for the DIY! Works like a champ on 2012 R! Your efforts are appreciated.

[erose914]

So I tried getting my rear fog to work today for the 3rd time, and I'm still not sure what's wrong... Here's what I can figure out:

- I have the euro headlight switch with auto and rear fog. P/N 3C8 941 431 J
- I did the proper wire switch and I just put a new repair wire from PIN 7 on the headlight switch > PIN 17 on the T52/A CECM.
- I'm not 100% sure if the repair wire from PIN 3 on the headlight switch > PIN 19 on the T52/A CECM harness is working correctly because I messed it up previously while trying to get it in, but I don't think this should cause trouble with the rear fog
-If I leave byte 18 at 20 (NA spec) and put the headlight switch to the full on position, the rear fog is on whether in reverse or not, the right reverse works correctly. The rest of the lights seem to be working normally. All the rear lights are throwing faults (obviously)
-If I turn byte 18 to 21 (I tried this because people were having success with this without rear fogs) The rear fog is always on whether in reverse or not, nothing changes whether the rear fog position is on or not on, the rest of the lights function correctly. I also get this fault in VCDS:

Tuesday,16,April,2013,16:37:19:59569
VCDS Version: Release 11.11.5 (x64)

Address 09: Cent. Elect. Labels: 1K0-937-08x-09.clb
Control Module Part Number: 1K0 937 084 G HW: 1K0 937 084 G
Component and/or Version: BCM PQ35 B 110 0651
Software Coding: 6F180A3A94252AC4108800C170000C444E052186774D8DB0E4 8420248040
Work Shop Code: WSC 01357 011 00200
VCID: 3245C3157DC7D088E78
1 Fault Found:

01518 - Bulb for Back-Up Lights; Left (M16)
010 - Open or Short to Plus
Freeze Frame:
Fault Status: 01101010
Fault Priority: 2
Fault Frequency: 1
Reset counter: 154
Mileage: 11209 km
Time Indication: 0
Date: 2000.14.28
Time: 16:33:07

Freeze Frame:
Term 15 On
Voltage: 11.80 V
ON
ON
Term 50 Off
OFF
OFF


-If I have byte 18 set to 04 (ROW, correct for rear fogs) everything works correctly except for the rear fog, no faults and the rear fog position does nothing to any lights.


Anyone have any ideas? I've tried everything I can think of, I'd be willing to try any other ideas people might have.

[deepfry]

Would be nice if the front LED could come on full brightness when the switch is in the parking position though, wonder if that could be done via coding?

Seeing this thread still being alive I thought I would just answer my own question here as I just found out recently that someone has already figured out how to keep the LED DRL at full brightness when light switch is at parking position:
Stopping LED DRL Dimming

Under central electric long code in VCDS, manually change the value of byte 25 from 84 to 86. I tried it on my Golf R last night and it worked as expected. I have OEM LED tail lights with fog and euro switch with rear fog. When the switch is at parking position the following lights will be on: city lights (if you have previously enabled), side markers, LED DRL (full brightness), and tail lights.

When hand brake is engaged the DRL will go back to dimmed mode but that's okay with me.

[cochino2000]

Hello guys,

Today I decided to install the LED tails with fog. I Installed the euro OEM rear fog switch and followed the directions exactly the way Tom ( DerGolfGTI ) mentioned it. What should I say it worked perfect..
Big thanks to DerGolfGti

Regards

Torsten

[9900rpm]

Anyone know the VCDS coding to use if I want to do an LED rear fog light as well as LED reverse light? If I can avoid it, if rather not use load capacitors. With current coding, I will get bulb out error.

[cryan7755]

I made the same modifications (Smoked Euro Led Tails with Rear Fog, They look amazing on my Steel Grey R), however I did install the Euro Auto headlight switch with front and rear fog positions (planning to add the Light Sensor to enable Coming/Leaving home functions for the auto setting). I'm going to wire up the City Lights to the Front fog position on the headlight switch as soon as I can pick up the extra repair wire from my local dealer. I believe I have the process figured out. This way I have manual control of the City Lights on my R while the switch is in any of the ON positions. Sure I could just use them as is, but with the extra available position on the switch, I figured I would add the option to control them manually. I also ordered the 6000k LED bulbs for the City Lights to give them a bit more Kick on the luminosity scale. I'll post Pictures and process once I have it completed and working.

[9900rpm]

That sounds great. Can you share where the repair wires should be hooked to, both at the switch and at the city lights? I don't believe Golf R's have a fog light harness of any type, up front.

[AMD IS THE BEST]

That sounds great. Can you share where the repair wires should be hooked to, both at the switch and at the city lights? I don't believe Golf R's have a fog light harness of any type, up front.

This is a document I wrote up for my last car (2010 Jetta TDI) which used the same style CECM as our Golf R's. It should be identical as far as repair wires, CECM pins and switch pins:

http://njsphoto.com/doctemp/Bi-Xenon%20Upgrade.pdf

Most of the document is unnecessary but the front and rear fog lights are covered as far as wiring. The coding is different though, so please don't use that.

[9900rpm]

This is a document I wrote up for my last car (2010 Jetta TDI) which used the same style CECM as our Golf R's. It should be identical as far as repair wires, CECM pins and switch pins:

http://njsphoto.com/doctemp/Bi-Xenon%20Upgrade.pdf

Most of the document is unnecessary but the front and rear fog lights are covered as far as wiring. The coding is different though, so please don't use that.

If I'm reading this correctly, to do what you want to do (activate city lights with fog light "pull" from euro switch), you would have to run repair wires from the CECM at pins A25 and C25 to the headlight connector at the headlight, as well as running the repair wire from switch to CECM. This opens up another whole can of worms if you're trying to run LED city lights, because the CECM will register LED's as a bulb out. I don't think there's a provision to activate fog lights, but sense them as led's, as in the led tails, or with led license plate bulbs.

[AMD IS THE BEST]

If I'm reading this correctly, to do what you want to do (activate city lights with fog light "pull" from euro switch), you would have to run repair wires from the CECM at pins A25 and C25 to the headlight connector at the headlight, as well as running the repair wire from switch to CECM. This opens up another whole can of worms if you're trying to run LED city lights, because the CECM will register LED's as a bulb out. I don't think there's a provision to activate fog lights, but sense them as led's, as in the led tails, or with led license plate bulbs.

You did read that correct. And I agree, LED's would most likely trigger a fog light out warning unless you get "no error" or "canbus" 194's. I let a friend borrow my VCDS but I'll be getting it back tonight to check and see if there is a check box for front fog lights.

[AMD IS THE BEST]

Confirmed, my '13 Loaded R has an option for front fog lights. Still doesn't necessarily mean that the pins are there though. I'll look into it tomorrow.

[FOOMZ18T]

Just to clarify, It looks like i'll receive my non-fogs tomorrow and I was wondering if I install them(without coding) will they will still function properly besides the bulb out light?

I ask this because I wont be able to get coding done till the weekend and I want to get rid of the horrible stock tails as soon as possible

[CSG_R]

Edited: posted on wrong thread. My bad!

[9900rpm]

Confirmed, my '13 Loaded R has an option for front fog lights. Still doesn't necessarily mean that the pins are there though. I'll look into it tomorrow.

Mine has it too. First time I went through VCDS I saw that option. I don't think that means anything more than that the CECM has a provision for it. Doesn't mean there is any wiring or anything.

I guess we need to look for coding that will beat the bulb out indicators now. I already have those Bold Sport things (wired to the side markers for now), and would like to keep them.

[AMD IS THE BEST]

Mine has it too. First time I went through VCDS I saw that option. I don't think that means anything more than that the CECM has a provision for it. Doesn't mean there is any wiring or anything.

I guess we need to look for coding that will beat the bulb out indicators now. I already have those Bold Sport things (wired to the side markers for now), and would like to keep them.

There's no doubt in my mind that the wiring is not there. VW doesn't even run unnecessary wiring that I've seen. If the CECM has the actual pins in the CECM, then there's a good chance the CECM is capable of triggering fog lights.

In a Euro vehicle, the city lights would be activated by the running lights. I see now reason why people should just run them right from the side markers. I personally wanted to do something different and actually use the all the functions of my Euro switch.

[Denver_Larry]

So I bought this euroswitch a little while back before doing a ton of research on the subject.



My concern is that I haven't seen this particular part number pop up in any discussions, and now that I look at the sticker closer it seems like it may not be an actual OEM part. can anyone shed a little "light" on this? I have LED tails w/fogs on the way and just want to have all my ducks in a row when it comes time to slam them in.

[deepfry]

So I bought this euroswitch a little while back before doing a ton of research on the subject.

My concern is that I haven't seen this particular part number pop up in any discussions, and now that I look at the sticker closer it seems like it may not be an actual OEM part. can anyone shed a little "light" on this? I have LED tails w/fogs on the way and just want to have all my ducks in a row when it comes time to slam them in.

This P/N has been mentioned in many places, just google the P/N.

[mo4mo]

Got my pre-loved LED tail lights with fog light and harnesses from a fellow member. Got the right switch and the repair wires from my work (dealer). Borrowed my techs' pin pulling tools and VAGCOM and everything is working perfectly. Thanks for a great How-To.

[mercury26]

Thanks for the notes on the install. Worked like a charm for me, I installed LED Tails with Rear Fog and enabled Parking Lights.

Thanks Again,

Chuck

[Tranzit]

Used these below, worked great, as usual. Super metal quality and strength.
Can't tell you how many pins I've extracted with it, and they wont bend or break if dropped. Dont ask me where to find them, I have had them for a long time, that I dont recall where I got them.



I did the two wire swap (28 and 47) yesterday, before doing the trigger wires (they come today), just so I dont always have the rear fog on, and a missing front passanger side DRL (got enough comments about it to move my ass) after coding my leds with fogs and euro switch, and set the byte 18 coding to 4.

Worked as expected. When I get to it, I will install the trigger wires to manually control the activation of fog and parking lights.

Near future upgrade is getting the front parking lights with LEDs to light up in the second switch position.