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Discussion Starter · #1 ·
Foglights Retrofit (CECM Method)
by the.ronin
This document is for informational purposes only. Any vehicle modifications should be done by a certified VW mechanic. Neither the author nor this site will be held liable for actions taken resulting from the information set forth herein.
Note that this procedure requires a highline central electronics control module (CECM) and a foglight capable light switch. The benefits of wiring foglights via the highline CECM include the ability to toggle options associated with fogs via Vag Com and burn-out bulb indicator functionality. Fog lights may also be retrofitted via relay directly to the light switch. But that's just ghetto, man.
MY06 2.5L Jetta package 1 without fogs ...

Retrofitted fog lights ...

Parts Needed
Projector Fog Light Assembly (Left) - 1T0 941 699 B *
Projector Fog Light Assembly (Right) - 1T0 941 700 B *
Foglight Grill Slats (Left) - 1K0 853 665 E 9B9
Foglight Grill Slats (Right) - 1K0 853 666 E 9B9
Nuts (6x) - N 905 353 01
Screws (6x) - N 090 294 1
Zip ties
Kufatec Wiring Harness **
* Part numbers are for projector foglights and not reflector fog lights. Projector bulbs (H11) are included with the projector fog light assembly.
** As of writing, Eurowires is no longer kitting fog light harnesses. Other vendors may carry these or with a little research, you can kit your own. Be sure to wire the right plug (H11 for projectors or 9006 for reflectors) and also get the wiring harness for the switch to the CECM.
Tools Needed
* Required tools. All others will just make your life a whole heck of a lot easier.
* Wrench 10 mm
* Groove Joint Pliers
* 13 mm socket
* 10 mm socket
* T20 torx bit
* T27 torx bit
Precision flathead screwdriver 2.5 mm or 3.0 mm
Trim removal tool
Note that you may need other socket sizes and torx bits other than those mentioned however none are particularly extraordinary and should all be included in your socket and torx sets.
Summary of Procedures
Part 1 – Clearing out the engine compartment.
Part 2 – Installing the foglight assemblies.
Part 3 – Wiring the CECM and light switch.
Part 4 – Vag Com and adaptation procedures.
Note that certain steps may be avoided entirely, however I found the procedures outlined below to be the most effective way to retrofit foglights. For example, a few others have found no need to remove the front bumper, however securing the harness may prove difficult. Additionally, you may also forego removing the battery, however this would require running the wiring harness around the engine bay (not clean); finding a different grounding bolt; and threading the harness through the firewall much more difficult.
Part 1 - Engine Compartment
1. Begin by disconnecting the negative terminal then the positive terminal of the battery with the 10 mm wrench.
2. Remove the plate in front of the battery. Remove the battery itself (bastard's pretty heavy). Then remove the plate to the rear of the battery. The plates snap right off.
3. The engine cover needs to be moved out of the way to get to a bolt holding down the battery tray (bottom right corner of red box). Use the groove joint pliers to carefully open and move the air intake clamp back onto the piping so it can be disengaged (red box).

4. Remove the T20 torx screws on each side of the intake pipe as well. Pop off the engine cover and move it slightly to the left to make room (4 points locking the engine cover - start at the top left).
5. There are three bolts securing the tray to the chassis (red circles) and one larger bolt securing a plate on the tray (mentioned in step #3). Note the path of the existing wiring harnesses and direction of the firewall. Also note the location of the grounding bolt (just outside of the photo).

Part 2 - Foglight Assemblies
6. With the engine bay cleared out, proceed to remove the front bumper. Place carpeting, mats, or cardboard under the bumper so you have something to place it on without scratching it. Begin by removing the sidemarkers and unlocking the bulbs.

7. Put the key into the "on" position and turn the steering wheel all the way to the right. Remove 5 torx screws in the driverside wheel well (red circles show general locations). Turn the steering wheel to the left and remove the 5 torx screws in the passenger side wheel well.

8. Remove the front shield by unscrewing 2 torx screws up top (red circles) and 2 phillips screws in the grill (blue arrows). Remove two more larger torx screws (green circles) under the shield.

9. Proceed to remove the torx screws underneath the bumper itself. There may be eight or so - they are easily spotted.
10. Slowly pull the bumper out - note that the driverside sidemarker wiring harness will be attached to the bumper (red circle) - unclip the harness before fully removing the bumper.

11. Drop the wiring harness down the engine compartment and thread it through the driver side lower bumper opening.

12. Run the passenger side fog light harness and zip tie it to the radiator support (red circles). Be sure to leave enough slack on both ends to sufficiently reach the fog light assemblies secured to the bumper. Obviously clip the zip ties once they are secure.

13. Proceed to remove the old grill slats on the bumper. Start by removing one phillips screw in each of the grill slats (red circle).

14. The grill slats are further secured by various clips on the backside (red circles). You can try to ease them out with a flathead screwdriver but after some frustration, I just yanked those bastards right off.

15. You may not want to get too medieval with the more fragile chrome brows. I found that using a micro flathead screwdriver to undo each clip one at a time starting from left to right - pulling up on the brow as I went along - did the trick effortlessly. Sort of.

16. Replace the chrome brows onto the new fog light grill slats, polish, light a smoke, and relish das bling.

17. Now would be a good time to test fit the bumper to make sure you have left enough slack. Do not leave more slack than you need since that wiring harness still needs to run through the firewall to the CECM.

18. Insert the speed nuts into the existing holes in the bumper (red circles).

19. Plug the corresponding ends of each harness to the respective projector fog lights. Then screw each of the projector assemblies into their appropriate locations.

20. Once the assemblies are in place, proceed to reattach the bumper. Do not forget to re-clip the driverside sidemarker wiring harness. If you are having a hard time (and you will) screwing in the top torx screw in the wheel well, try pushing that side of the bumper in with slight force to make sure it is flush to the wheel well.
21. With the bumper firmly back in place, proceed to install the new grill slats by pushing them in with some slight force and replace the one phillips screw on each side.

22. Proceed to re-assemble the bumper (refer to steps #6 - #9 in reverse order). Do not forget to re-attach the sidemarker harness on the driver side.
Part 3 - Wiring the Foglights
23. Lay the main wiring harness along the path underneath the battery tray (red line). The harness will be threaded through the firewall (green circle) into the cabin. The grounding wire can be tapped into the bolt behind the battery on the wheel well (blue circle).

24. Inside the driver side cabin under the dash, remove four torx screws (red circles) to release the light switch fascia and footwell plating.

25. Carefully lower the footwell fascia and disconnect the OBD harness and footwell lighting harness. Use a small flathead to unlatch the can-bus connector (blue circle - two more latches on other side). Squeeze the lighting plug and pull to remove (red arrows).

26. Lift up the trim in front of the instrument cluster (pull back the steering wheel to make things easier) and remove the torx screw (red circle). I recommend wrapping that trim clip with napkins as that little bastard has a tendency to scratch anything it touches.

27. Remove the light switch by pushing in, turning right and pulling out. Disconnect the light switch. There will be one torx screw behind the switch that needs to be removed.
28. Pry off the fuse panel and proceed to carefully remove the light switch fascia.

29. Be careful as the dimmer switch will still be connected (red circle). Disconnect the dimmer switch.

30. With the footwell and light switch fascia removed, you will be able to see the CECM under the dash. Plugs A, D, and E will need to be removed to connect the appropriate wiring harness. Letters are engraved near their respective plugs.

31. Starting with the light switch harness, disconnect the connector to the wiring harness by unlocking it with a micro flathead screwdriver. This will allow you to remove the connector itself.

32. Connect one end of the trigger wire (doesn’t matter which end) to pin #5 of the light switch. Note the small numbers on each corner of the connector denoting pin locations (red circles).

33. Reconnect the light switch connector to the light switch plug.
34. The trigger wire needs to be fed through the dash and to the CECM. Disconnect plug “E” from the CECM. Separate the connector from the plug by pulling out – in the photo, the connector will come out towards you.

35. Disengage the wiring locking mechanism on the connector by pulling the purple latch. There will be a tactile click once it is unlocked – you do not need to fully remove the locking mechanism.

36. Connect the other end of the trigger wire from the light switch to pin #6 of the CECM plug “E” (red box).

37. Re-engage the purple locking mechanism, re-attach the connector, and re-attach plug “E” itself back into the CECM. Note that the plug will not reconnect if the locking mechanism has not been re-engaged.
38. Thread the main wiring harness from the engine compartment through the firewall. Behind and above the brake pedal will be foam insulation which can be lifted off the pegs securing it into place. Behind the foam insulation will be a rubber grommet that be removed or punched through to thread the main harness.

39. The “RIGHT” foglight harness needs to be connected to plug “A” pin #4. Procedures outlined in steps #34 - #37 will be similar.
40. The “LEFT” foglight harness needs to be connected to plug “D” pin #2. Procedures outlined in steps #34 - #37 will be similar.
41. Clean up the wiring harnesses with zip ties and re-install the light switch and footwell fascias.
42. With the wiring all in place, proceed to clean up the engine bay by replacing the battery tray and battery and reinstalling the cover and air intake components.

Part 4 - Vag Com & Adaptation
43. Connect and load up Vag Com and go to address 09 Central Electronics. Click ON bit 0 of byte 0 and bit 2 of byte 18. Transfer coding and click DO IT. Note that there are other fog light related options that can be manipulated via Vag Com. Turn on the light switch and pull out once to engage the fog lights.

44. Window and sunroof adaptation should be performed after every battery disconnect. Roll down each window and the sunroof all the way and then roll up each window. This will re-activate auto up/down and recalibrate pinch detection.
45. Drive a few meters in a straight line to perform steering adaptations and clear the remaining lights in your dash.

******* End of DIY *******
Thanks to maloosheck (Vortex), Zeb of 1stvwparts, and many others.
Modified by the.ronin at 10:51 AM 5-7-2007

Modified by svander at 11:12 AM 5-7-2007

6,970 Posts
Discussion Starter · #5 ·
Re: (The_Black_Pearl)

Thanks guys. http://****************.com/smile/emthup.gif
Quote, originally posted by The_Black_Pearl »
Looks like the write up took just as long as the install.


276 Posts
Re: DIY: Foglights Retrofit (ZEBLOR)

nice write up!!!!... you should mention that you dont have to take the whole front bumper off... at least i didnt have to for my install.

6,970 Posts
Discussion Starter · #11 ·
Re: DIY: Foglights Retrofit (Rh3017)

Thanks Zeb and thanks for hookin me up with the parts!

Quote, originally posted by Rh3017 »
nice write up!!!!... you should mention that you dont have to take the whole front bumper off...

Quote, originally posted by the.ronin »
... Note that certain steps may be avoided entirely, however I found the procedures outlined below to be the most effective way to retrofit foglights. For example, a few others have found no need to remove the front bumper, however securing the harness may prove difficult ...

[edit] Although I am curious how you guys managed to secure the wiring harness without taking off the front bumper?

Modified by the.ronin at 9:39 AM 5-8-2007

243 Posts
Re: DIY: Foglights Retrofit (the.ronin)

http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif sick writeup, great photo, solid contributor to vortex 'again'! Good stuff rob

423 Posts
Re: DIY: Foglights Retrofit (the.ronin)

really nice write up, still not confident in doing this myself however...but only because i dont trust myself... http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif

282 Posts
Re: DIY: Foglights Retrofit (Rh3017)

Quote, originally posted by Rh3017 »
nice write up!!!!... you should mention that you dont have to take the whole front bumper off... at least i didnt have to for my install.

Same here, didn't remove the bumper.
Bump for a great write up.
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