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

[uS4f]

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.

 

[aragorn]

http://www.audizine.com/forum/showthread.php?p=4210776

Google finds that.

Sounds like a faulty light switch.

 

[uS4f]

i guess i will have to try the switch, thanks for the link

 

[uS4f]

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.

 

[zyxwv]

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.

 

[Woorlord]

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??

 

[zyxwv]

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?

 

[Woorlord]

CODING: See Ross Tech A4/B6 under Module 09 Central Electronics
Here you have to specify if you have a light sensor.

 

[Cockney Boy]

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

 

[zyxwv]

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)

 

[haloua2004]

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!!!

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)

 

[semoG]

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 ?

 

[quattro4]

likewisw, have the same prob on my2005 Audi A3

 

[NHN]

Wrong section mate & you will need vcds to diagnose this tbh as that will show you what connections are not making contact.

 

[hades-]

mine was light sensor

 

[quattro4]

Many thanks, I''ve pmd you for the vcds cable....

 

[adampad]

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?