Headlights coming on with ignition

[monkslayer]

Hello.I have searched the forum and haven't seen a problem really like mine.I own a 2004 Audi A4.Problem is that when I switch on the ignition my headlights come even though the headlight switch is in the off position.I have tried replacing the switch but still the same problem.Could someone help diagnosis this and hopefully provide me with a solution.Thank you in advance.

[walky_talky20]

Please be more specific, as there are a lot of exterior lamps on your car.

Are you getting the low-beam headlamps or hi-beam headlamps, which are illuminating with key ON?

Are there any other lamps which illuminate with them (ie: parking lights, fog lights, etc.)? Be specific.

[monkslayer]

The Low beam headlights,tail lights,licence plate lights,dashboard lights(all instrumentation lights to be precise),no fog lights however..basically it functions as though I have turned on the lights at the switch even though the the switch is at the off position.on the instrument panel..the light on sign comes on indicating the lights have been switched on...This happens when the key is at the ON position..

[imnuts]

Grab VCDS and scan for a code or codes. When you replaced the switch, was it a new switch? OEM? Did this happen suddenly, or did they occasionally come on previously. Does your car have automatic lights? Did you install the proper switch if you do have auto lights?

[monkslayer]

Yes the car does have automatic lights.I installed the proper switch(one with auto option).Also tried one without and the problem was still the same.The switches I tried were OEM but not new.I don't have much experience with VCDS(i am a newbie).I have a friend with one,which section should I look at specifically?

[ADCS]

perform an auto scan, it will check all installed modules.

[SlickFix]

Just to be clear, the switch is in the "Off" position, not "Auto" when it does this? Does it do the same thing with the switch in the "Auto" position?

[monkslayer]

Yes it is in the "Off" position..and it does the same thing as the the "Auto" function
...

[walky_talky20]

The Low beam headlights,tail lights,licence plate lights,dashboard lights(all instrumentation lights to be precise),no fog lights however..basically it functions as though I have turned on the lights at the switch even though the the switch is at the off position.on the instrument panel..the light on sign comes on indicating the lights have been switched on...This happens when the key is at the ON position..

Wow. This is an excellent answer. I am impressed. A+

[monkslayer]

Wow. This is an excellent answer. I am impressed. A+

I try;-)

[mobilesuit818]

I have this as well on my 05. There is no mechanical or electrical issues with this.

I remember reading something about ignition switch replacement but can't confirm

[diagnosticator]

Did this just start happening or has it always done this? There are coding options in the Central Electric Control Module that if set or not, will enable the lights to be ON all the time. The CECM controls all of the exterior lighting, The interior lighting is controlled by the Instrument cluster and the Convenience Control Module. It is also possible that the CECM is faulty, turning ON the exterior lights, and sending a lights ON message on the CAN buss, that turns on the interior dash lights the same way the interior lights are turned ON normally. It is unlikely a faulty CECM that has failed in this specific fault mode, will have any stored fault codes. If the problem has only recently started, disconnect the headlight switch, and see if the same symptoms occur with the switch removed from the harness connector. If this is the case, then there could be a fault with the wring to the headlight switch, or again, a faulty CECM. With the headlight switch disconnected from the wiring harness, it is normal for the headlights, running lights and dash lights to be ON with the key ON. This is the fail safe mode for a faulty headlight switch.

[monkslayer]

The problem just started on it's own.it hasn't always been like that.(according to the P.O).removed the switch and the headlights remained on together with everything else.will try looking at the wiring,maybe there could be a short.

[imnuts]

Do you have access to VCDS? It's possible that scanning for codes will point somewhere. My headlight switch was going bad, and occasionally, the lights would come on by themselves. There was a stored code for it at one point, but it didn't always give me a code when it happened.

[monkslayer]

I am getting access to VCDS today.Will scan and give an update on what I come up with..

[monkslayer]

Diagnosed the car and the result is a faulty headlight switch.looking at purchasing one now... Thanks all

[Legios86]

You find the problem? Tell me please how to fixit. (I have same problem)
Thank you.