I know a number of forum members have commented that they wish the Atlas had rear fog lights. I am one of them who wished that — so figured out a way to get them!
To do this, I (1) replaced the factory light switch with one that has a rear fog option, (2) replaced the left (drivers side) white reverse lamp with a bright red lamp, and (3) adjusted some adaptation channels using OBDEleven so that flipping on the rear fog switch would activate that bright red lamp. This means I only have one white reverse lamp, which wouldn’t be my first choice but which is street legal and not uncommon especially on European imports. Because I swapped out my dim, incandescent reverse lamp on the passenger side with a bright white LED, I find just one white light still gives me enough light to backup (although I have the "rear fog" activate when in reverse also, to give extra light).
To get the full effect, you will need:
- VCDS, OBDEleven Pro, or another VAG-COM coding tool (I used OBDEleven, ordered from ECS Tuning)
- A replacement headlight switch (or Light Control Module/LCM) with a rear fog light option, often called a “Euroswitch,” which you can order from your dealer, ECS Tuning, Amazon, eBay, etc. (VW Part # 5GG 941 431 worked for me)
- A bright red LED 194 wedge bulb that is compatible with the reverse light fixture (I special ordered mine from deAutoLED)
- A trim removal tool (I ordered from deAutoLED)
Here’s the instructions:
- Replace the light switch, which is surprisingly easy (pull out the old one, unplug it, plug in the new one, and slide it in). You just twist the old light switch a certain way and you can pull it right out. The proper wiring for the rear fog is already run and part of the plug. This video shows you all you need to know: https://www.youtube.com/watch?v=7Ir0Q6PX4Zo
- Replace the driver side rear reverse light with the red LED. To do this, you need to (1) open the tailgate, (2) find the tail light access panel on the inside of the tailgate door and pry it open with a trim removal tool, (3) squeeze the black tabs and pull out the white plastic housing that holds the bulbs, (4) swap out the reverse bulb for the red LED replacement, and (5) carefully put it all back together. Inner tail light access panel: http://i.imgur.com/b8C32Og.jpg .... What part looks like (on non-Premium Atlas) after it is pulled out: http://i.imgur.com/RmNsyqN.jpg
- The final step is to make a few tweaks to the coding.
- ----First, tell the computer that your light switch has a rear fog option by going to Module 09 Central Electrics > Adaptations > Außenlicht_uebergreifend > LDS_mit_Nebel_Schlusslicht and changing “no” to “yes.”
- ----Second, tell the computer that your left reverse light is a rear fog light by going to Module 09 Central Electrics > Leuchte28RFL LC11 > Lichtfunktion B 28 and changing “not active” to “Nebelschlusslicht wenn kein Anhaenger gesteckt”
- ----If you stop there, then the light will ALSO continue to come on when you go into reverse. I prefer it that way as the red light gives me some extra illumination. If you prefer the light ONLY come on when the rear fogs are on, then you should change Lichtfunktion A 28 from “Rückfahrlicht” to “not active”
- I wasn’t quite satisfied that the housing for the reverse bulb was properly projecting the light of the red LED bulb to be bright enough to other drivers for rear fog light purposes, so decided to add a little brightness through the factory tails. The tail lights on the Atlas run at 10% power (with the outer tails kicking up to 100% power when the brakes are activated). Using OBD11, I programmed the tail lights to run at 40% power when the rear fogs are activated. Even though they look bright in the picture above, it's only 40%. The brake light still kicks them up to 100% power, which seems to still be a noticeable enough difference for someone travelling behind me. If you want to play around with this, I suggest you read dv52's excellent white paper entitled "How MQB platform vehicles (like the Mk7 Golf) control external lights -preliminary observations" combined with this post (for SEL Premium): http://forum.obdeleven.com/post/13736/thread
If you do this, just remember that the rear fog light should only be used when it is particularly foggy or there are other weather conditions that greatly reduce visibility. Don't be one of those guys that gives rear fog lights a bad name... Also, anytime you mess with the coding, you do so at your own risk! Finally, this worked for me and my Atlas, but may not work for you or your Atlas.