Dipped Headlight

B6/7 S4/RS4
#21

I’m stumped.

The “issue” is on the driver’s side. First item I did was swap the D1S bulbs to see if the problem moved to the passenger side with the bulb. It did not. Next item, swap the ballasts to see if the issue moves to the passenger side. It did not. So now we know both the new D1S bulbs and both the new ballasts work perfectly…on the passenger side. Which tells me so do the old parts I removed. I don’t mind having two sets of ballasts and bulbs. What’s killing me is the issue I can’t resolve.

When I first swap the bulbs, the driver’s side fires up but then goes out and I get the “dipped headlight” warning. When I swap the ballasts, same thing – fires up then goes out and the warning light pops up.

When I cleared the codes yesterday, directly after installing the new parts, there was indeed 4 or 5 fault codes. Same ones listed in an AZ thread I was referencing. Then I vag’d the ballasts to talk to the ECU etc, checked the codes one last time and still had the issue.

Fast forward to today, I do my swap with the parts but the weird thing is even though I’m getting the error on my DIS it’s not coming up when I scan with the vag cable?? I even took video to prove this is accurate.

Another odd thing, at least to me, is each time I open a door or the hood etc, the driver’s side D1S bulb that I’m having an issue with is flickering like a mofo. I took video of this as well.

So, I start the car and I instantly get the main headlight warning on the DIS. I turn the headlight knob to auto or “on” and instantly get the dipped headlight error on the DIS. Yet nothing pops up in vcds when I scan for fault codes under xenon 55 whatever.

P.S. I can take the bumper cover off and remove the headlights in 20 minutes flat. I can’t line that mother up the way I want if my life depended on it. FML.

P.P.S On a positive note I might have lost 5lbs of water weight while in the garage.

#22

I honestly would PM Phil (fly300kts). I’m not saying he’ll have an answer, but he’s torn these headlights apart probably more than anyone else around (and he’s done several indepth repairs, not just his little LED add-on).

I can imagine how frustrated you are though, sorry for all this crap. Sounds like it’s about time to just buy a new one from a part out car and then hope it’s not a wiring issue to the headlight lol.

#23

Phil has been great, he is who I have been messaging with for guidance. I’m awaiting his latest response to the info I shared above. I sent it to him via pm on az.

Aside from faulty wiring, which would be strange imo, I can’t imagine what else it could be. I haven’t even checked yet but is there a fuse just for the low/high D1S bulb? Maybe it’s corroded? I’m reaching but can’t for the life of me figure out what the culprit is.

#24

Phil is stumped too, he has never heard of such behavior when it comes to the headlamps and what’s happening to mine.

So, I responded with the following and was hoping someone here could chime in too.

I’m far from an electrical or headlamp expert so please excuse the following questions if they are unrelated or do not make sense:

-Are there relays and or fuses for each headlamp? Possible that one failed?
-Are there control units (other than the ballast unit) for each headlamp? Possible that one failed?

When the car goes through the self check upon start up, something has to send a signal down to the headlamps to either check for voltage or something that can send a message back to indicate they are ok…what would that unit be called? I have to assume something between the headlamps and the dash display is faulty - correct?

Edit: I guess the smart thing to ask for would be a wiring diagram. Does anyone have access to this for a B7 RS4? I’d like to follow the path from the headlamps back so I can begin to test different theories. TIA.

#25

At this point you have fuses, the actual headlight housing, wiring, and the control module left.

Fuses are easy to check and they are behind covers on each side of the dash between the door and dash. Open the front door and there is a opening towards the bottom that the metal key shank portion of the key fits into so you can pop it off. I would check both sides - driver and passenger.

Next if you have a spare headlight housing or can borrow a buddy’s car (I would think even a Xenon equipped B7 A4 would work) for an hour then you can try swapping out just the driver’s side housing. Lot of work but at this point the bumper falls off almost. I remember a new housing being like $400+ at the dealership and probably somewhat cheaper from other places but not much.

Then you have the control module and wiring. I remember the control module being behind the glove box. The glove box comes out pretty easy with a few 8mm bolts. The wiring shouldn’t be an issue unless your car has been in an accident.

I would put my bet on the 55 xenon control module behind the glove box but without being there it is only a guess.

#26

Yeah, I’m familiar with those two fuse panels, will check them now. I doubt it’s that simple but I will check anyway. If the fuse acutally blew, I wouldn’t be able to get any power to the bulb at all and since it flickers and randomly goes on sometimes I don’t think it’s the fuse. I will check to rule that out though.

That’s a good idea but I doubt I can find someone willing to do that lol. I will ask though.

My money is on that too. Thanks for letting me know where it is. Is there a way to test it’s functionality through vag-com?

I realized I could pull up the wiring schematic myself on my Ebahn manual CD Rom. Here is the left HID info:

http://i834.photobucket.com/albums/zz269/NY07RS4/LeftHIDwiringinfo.jpg

#27

I tried to complete the “output tests” through vcds to see if the headlights would comply. Nada. And, both sides are coming up with errors now…and…lol…both headlights will fire up randomly and work and then turn off?! WTF, I’m really hoping it is that controller unit so I can replace it and be done with it.

#28

Hi. Brand new here. My '06 S4 Avant has had this problem intermittently since it was new. Listed it on the service notes during a few of my 4yr/50k warranty services and of course they could not replicate. Now the car is 7 years old and 112k miles and one or both lights flickering and failing every night now. I keep driving, turn the switch to indicators only setting, wait for the remaining headlight to shut-down, then refire them by going to “auto” to manual on. Sometimes I have to do this twice, three, four, five… times till the lights behave. Then they might quit again after an hour and a half of driving. Crazy.

Anyway, I’ve search and searched the net looking for a definitive answer to this problem and nobody has come up with the root problem. Some say bulbs, some ballasts, some say there’s a guy who will rebuild your ballasts and do other mods and that’ll fix it.

Does anyone have the answer? What’s the true fix? Thanks in advance for any help.

#29

You came to the right place I had this same issue on my b7 s4. I camt say 3xactly whats wrong with your car but I cam help you track it down like I did…do you have vag-com