Results 1 to 7 of 7

Thread: "Downgrade" Passat W8 to halogen headlights

  1. #1
    Verified VCDS User
    Join Date
    Aug 2016
    Location
    USA
    Posts
    7
    Post Thanks / Like

    "Downgrade" Passat W8 to halogen headlights

    I want to "downgrade" the headlights on a 2003 Passat W8 from the original Xenon to standard halogen.

    To answer the "why..."

    In January I bought two black 2003 Passat W8's.

    1. A 6-spd manual to keep, with broken headlights, tail lights, dinged fenders/bumper cover, missing grille, missing badges, missing exhaust, aftermarket wheels, etc. generally needing some TLC.

    2. A high-mileage automatic in good cosmetic shape for parts + OEM wheels (Madras.)

    So I swapped what I needed onto the 6-spd and now am trying to find a buyer for the parts car.

    No takers so far. Mostly people are looking for complete cars. So I'm putting the cosmetically-bad parts back on the parts car, plus an extra grille and tail lights I had from a regular Passat.

    So it already doesn't have any of the distinguishing markers that identify it as anything but a 1.8T Passat. And I have an extra set of halogen headlights, so why not put them on.

    I know the connectors are different, but the colors of the common wires are the same, so I assume everything related to hi/lo/turn/city lights is the same. I have the pigtails for the halogens so I can make the adapter.

    Which only leaves coding. I believe this can be done, correct? Code it for halogens and just don't connect the extra wires on the harness?

    My daughter has a 2.8 v6 with halogens, so I can read it's settings for comparison, as soon as I find where it is in VCDS.

    This is somewhere under 09 Central Electronics, I think, right?

  2. #2
    Ross-Tech Employee Sebastian's Avatar
    Join Date
    Feb 2014
    Location
    Magdeburg, Germany
    Posts
    1,948
    Post Thanks / Like
    There is no spoon (central electronics). Everything is hard wired.
    Sebastian @ Ross-Tech.com // VCDS Rookie since 2003

    »Nichts erweitert das eigene Wissen mehr,
    als die Meinung eines Andersdenkenden.«

  3. #3
    Verified VCDS User
    Join Date
    Aug 2016
    Location
    USA
    Posts
    7
    Post Thanks / Like
    Quote Originally Posted by Sebastian View Post
    There is no spoon (central electronics). Everything is hard wired.
    Which means what?

    1. It will work with no coding, just don't connect the extra wires from the original harness, or
    2. It's not possible?

  4. #4
    Benevolent Dictator Uwe's Avatar
    Join Date
    Jan 2014
    Location
    Earth
    Posts
    26,325
    Post Thanks / Like
    Blog Entries
    1
    Exterior lighting in the B5 (and B5.5) is not computer-controlled. OK, with Xenons, there's a Headlight Range Controller at address 55, but on/off and what lights are on when is all old-school; wires and relays and such. Air-Gap the Xenon Range controller. Re-code 19-CAN gateway with whatever value is there to make it rebuild its internal installation list. Beyond that, it's a matter of having the correct wiring, switch and relay configuration for the halogens.

    -Uwe-
    The engineering problems are likely insurmountable. It would be like proposing to land a rocket booster section on a barge floating in the middle of the ocean.

  5. #5
    Verified VCDS User
    Join Date
    Aug 2016
    Location
    USA
    Posts
    7
    Post Thanks / Like
    OK, so it's possible.

    I think the headlight range controller is the extra wires on the connector, and is sometimes also called auto-leveling. Is that right?

    By "air-gap" as a verb, do you simply mean disconnect and insulate so there's no connection?

    Then recoding the can gateway makes it re-evaluate what hardware is present? (I.e. recognize that the range controller is not there, kind of like Windows plug-and-play?)

    Thanks for all the help. I've got 4 VW/Audi cars in my family (5 counting the parts car) so VCDS is quite useful.

    Quote Originally Posted by Uwe View Post
    Exterior lighting in the B5 (and B5.5) is not computer-controlled. OK, with Xenons, there's a Headlight Range Controller at address 55, but on/off and what lights are on when is all old-school; wires and relays and such. Air-Gap the Xenon Range controller. Re-code 19-CAN gateway with whatever value is there to make it rebuild its internal installation list. Beyond that, it's a matter of having the correct wiring, switch and relay configuration for the halogens.

    -Uwe-

  6. #6
    Benevolent Dictator Uwe's Avatar
    Join Date
    Jan 2014
    Location
    Earth
    Posts
    26,325
    Post Thanks / Like
    Blog Entries
    1
    I can't think of any reason why it wouldn't be possible, but I don't know exactly what's required in terms of hardware mods (wiring, switch, and relays) to get the halogens to function properly. You should probably compare relevant sections of the wiring diagrams for a halogen and a xenon car.

    Yes, "Air-gap" means disconnect.

    Yes, re-coding the CAN gateway in these cars makes them re-evaluate what's actually installed.

    -Uwe-
    The engineering problems are likely insurmountable. It would be like proposing to land a rocket booster section on a barge floating in the middle of the ocean.

  7. #7
    Verified VCDS User
    Join Date
    Aug 2016
    Location
    USA
    Posts
    7
    Post Thanks / Like
    So far, I've made a temporary adapter for the right headlight, and tested hi, lo, turn, and drl bulbs. All work. Haven't tried disconnecting the range controller yet.

  8. Likes Uwe, Dana liked this post

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •