1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Head lights always on and Auto Dim Mirror not working???

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by uS4f, Oct 6, 2009.

  1. uS4f
    Offline

    uS4f S4 Cabriolet 04

    Joined:
    Jul 28, 2009
    Messages:
    26
    Likes Received:
    0
    [Oct 6, 2009]
    my healdights stay on whether i have them on auto or 0, the dimming mirror does not switch on too, i guess they are linked somehow. it seems to be a fault others have experienced but there are no answers on how to solve it?

    any one experienced this problem? its fault code 01800 - Light Switch (E1) i have read on audizine you can code the headlights for a region code ?? will that make a difference, anyone coded their headlights?

    i was just going to buy a new switch but on audizine people who experinced this fault said a new switch did not solve the problem?

    my car is audi s4 cab 2004

    any help would be appreciated.
    #1
  2. Ads

    Ads

    [Sep 20, 2014]

  3. aragorn
    Offline

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Joined:
    Jan 30, 2008
    Messages:
    15,571
    Likes Received:
    313
    [Oct 8, 2009]
    #2
  4. uS4f
    Offline

    uS4f S4 Cabriolet 04

    Joined:
    Jul 28, 2009
    Messages:
    26
    Likes Received:
    0
    [Oct 8, 2009]
    i guess i will have to try the switch, thanks for the link
    #3
  5. uS4f
    Offline

    uS4f S4 Cabriolet 04

    Joined:
    Jul 28, 2009
    Messages:
    26
    Likes Received:
    0
    [Oct 29, 2009]
    just an update really, got a new switch from audi and guess what?? same problem headlights stay on, what the hell can it be ?? i am thinking of disconnecting the auto dimming mirror if that is possible , i would appreciate if someone can tell me how to do this? or any other ideas i could try.
    #4
  6. zyxwv
    Offline

    zyxwv New Member

    Joined:
    Dec 11, 2009
    Messages:
    3
    Likes Received:
    0
    [Dec 11, 2009]
    Hi,
    My car has the same problem too. My battery drained out because of cold weather and this problem started. Then I replaced the battery and cleared the codes. But I still have the lights ON on Auto and O and also the dimming mirror has no power.

    Were you able to figure out the solution. Any help is greatly appreciated.
    #5
  7. Woorlord
    Offline

    Woorlord shifting to Hyperspace... . VCDS Map User

    Joined:
    Dec 8, 2007
    Messages:
    948
    Likes Received:
    12
    [Dec 11, 2009]
    From Ross-Tech web site:

    01800 - Light Switch (E1): Implausible Signal

    Possible Symptoms


    • Parking Light Status Lamp (in Instrument Cluster) stuck ON
    • Self Dimming Rear View Mirror not working
    Possible Causes


    • Light Switch (E1) faulty (or switched to an intermediate position)
    • Wiring/Connectors from/to Light Switch (E1) faulty
    Possible Solutions


    • Check Light Switch (E1)
      • See Measuring Value Blocks (MVB)
    • Check Wiring/Connectors from/to Light Switch (E1)
    Special Notes


    • When found in Audi A3/S3 (8P): Central Electronics, check Light Switch Status in Measuring Value Block (MVB) 017 and 018.
    • When found in Audi A4/S4/RS4/Cabriolet (8E/8H): Central Electronics, check Light Switch Status in Measuring Value Block (MVB) 006.1.

    Looks like it could be a duff Mirror if the light switch has been changed??
    #6
  8. zyxwv
    Offline

    zyxwv New Member

    Joined:
    Dec 11, 2009
    Messages:
    3
    Likes Received:
    0
    [Dec 11, 2009]
    Thanks for the reply. I will check these things right away.

    I have a question though. The rear view mirror has the light sensor whose signal is used by the Auto light switch to switch on or off the lights. But the rear view mirror has got no power and so the sensor is off. I am suspecting the wiring to the mirror has gone wrong.

    I read somewhere that we need to use the correct code settings for the headlight & mirror to work accurately. Do you by any chance have the code?
    #7
  9. Woorlord
    Offline

    Woorlord shifting to Hyperspace... . VCDS Map User

    Joined:
    Dec 8, 2007
    Messages:
    948
    Likes Received:
    12
    [Dec 12, 2009]
    #8
  10. Cockney Boy
    Offline

    Cockney Boy Member VCDS Map User

    Joined:
    Nov 26, 2007
    Messages:
    481
    Likes Received:
    6
    [Dec 12, 2009]
    You may have a faulty rain/light sensor (infront of your mirror) this should be changed when you have a new windscreen, bu they are known to fail on their own
    #9
  11. zyxwv
    Offline

    zyxwv New Member

    Joined:
    Dec 11, 2009
    Messages:
    3
    Likes Received:
    0
    [Dec 15, 2009]
    Thanks for the inputs. My problem has been fixed. I am including the details for anyone who might have the same issue. I recoded the settings in the electrical module specifying that there is a light sensor and it solved the problem. In the 5 digit code, the 4th digit should be 1 (X1XXX)
    #10
  12. haloua2004
    Offline

    haloua2004 New Member

    Joined:
    Apr 10, 2010
    Messages:
    1
    Likes Received:
    0
    [Apr 10, 2010]
    Hello,

    I have a 2005 audi a4 convertible and my interior mirror with auto dim and compass stopped working after changing the battery. I've replaced the headlight switch, tried a new interior mirror, still nothing... Can you tell me how you've fixed that issue?
    Thanks

    A newbie!!!


    #11
  13. semoG
    Offline

    semoG New Member

    Joined:
    Aug 20, 2010
    Messages:
    2
    Likes Received:
    0
    [Dec 13, 2011]
    I have and Audi A3 8P MY2004, but my auto-dimming mirror doesn't dimm but it has the green lkight active.

    Can someone tell me what can I do to fix this ?
    #12
  14. quattro4
    Offline

    quattro4 New Member

    Joined:
    Dec 20, 2006
    Messages:
    23
    Likes Received:
    0
    [Jan 18, 2012]
    likewisw, have the same prob on my2005 Audi A3
    #13
  15. NHN
    Offline

    NHN Retrofitter - Audi - VW - Skoda - Seat Site Sponsor VCDS Map User

    Joined:
    Jan 14, 2008
    Messages:
    27,320
    Likes Received:
    1,229
    [Jan 18, 2012]
    Wrong section mate & you will need vcds to diagnose this tbh as that will show you what connections are not making contact.
    #14
  16. bez101
    Offline

    bez101 Yorkshire & Humber Rep. Regional Rep VCDS Map User

    Joined:
    Jul 8, 2008
    Messages:
    8,806
    Likes Received:
    500
    [Jan 18, 2012]
    mine was light sensor
    #15
  17. quattro4
    Offline

    quattro4 New Member

    Joined:
    Dec 20, 2006
    Messages:
    23
    Likes Received:
    0
    [Jan 20, 2012]
    Many thanks, I''ve pmd you for the vcds cable....
    #16
  18. adampad
    Offline

    adampad New Member

    Joined:
    Feb 5, 2012
    Messages:
    1
    Likes Received:
    0
    [Feb 5, 2012]
    I've had the same problem on my 2004 A4. Headlights always on and the mirror doesn't dim or show the direction anymore. This happened after I was working on the car and let the battery go dead. I did have one headlight unplugged when the battery died (not sure if that matters).

    If I buy a vag-com cable off of Ebay, will I be able to recode whatever it is I need to recode?
    #17

Share This Page