2008AudiA8L

I did a search before posting this and didn't come up with anything. The headlight going out seems to be discussed a bit, but not with the cornering light also being out at the same time.

The first symptom is the right headlight goes out sometimes, dash indicator comes on that a bulb is out. Second symptom is that the corner bulb on the right side also is out (halogen bulb that illuminates to the side only when turning steering wheel to the side).

Turning lights on and off with the switch usually gets headlight and corner bulb to come back on.

So my thinking is its not the headlight bulb that is going bad, nor the igniter, nor the ballast because each of these would not have an effect on the corner bulb also going out / coming back on. The corner bulb is just a halogen bulb and not a HID. Other thought I had was a bad ground shared by both the HID and halogen bulb, but that wouldn't explain the bulbs coming back on from just turning on and off the lights. Also, I don't think it's the headlight switch because in one experiment I left the headlight switch alone and instead turned the car off. When I started the car again a few moments later the headlights came on.

Any other thoughts of what I should check?

mishar

It could be J668 Right Headlight Output Stage. That's the module on the outside of the right light. It controls all bulbs and motor in that lamp.

greenz

I'm having the exact same issue. My passenger HID bulb goes out intermittently as well took it to the shop they replaced both the bulb and ballast still didn't work. mishar can you elaborate on what part p/n you think it might be and exacly where it is located i would like to try and replace mines myself if possible.

05SilverA8

There were some previous threads on this if the module is the issue here

mishar

According to Bentley Wiring Diagram it is J668 Module, ETKA states 4F0 941 329 D, and here you can buy it new. There you can see its position too. Just behind the HID light. To access it you have to remove front wheel and wheel liner.

It looks like left and right modules are same, so for the start you may switch them and check if the problem is switching sides too. Or it may just disappear if it is just a contact.

Than I would try to find a used one.

2008AudiA8L

Good suggesting about switching sides as that is an expensive part (but still cheaper than taking the car to the stealership for diagnosis). I already splurged on a set of new headlamp bulbs that I didnt need. I ordered the pair after the first time my headlamp went out as I just assumed it was a bulb. Of course, the next time I drove the car in the evening (and hadnt put the new bulbs in) and the bulb fired right up and didnt go out for like another week later, I still wasnt convinced if it wasn't just the bulb filament with a hairline break. Then I started looking closer and realized the cornering lamp was out at the same time the bulb was out. I guess I'll just put the new bulbs in while I am fiddling at the lamp assemblies now since they are probably somewhat worn out anyway on a 5 year old car.

Would it be quicker to just pull the front bumper off rather than removing the wheel liners? (as they often put up a fight to be removed completely from the wheel house).

First, I will check with my VAG-Com to see if there are any error codes being given off.

RobertV

I have the same issue. Right side lights (HID & corner light) work when they want to. I swapped all components (bulb, ignitor & module) from right to left side works fine. Kept right side components on left side and put left side components on right side. Same issue on right side.
I was guessing a bad ground since two lights go out.
Please share your findings.

2008AudiA8L

Since you've already taken the trouble to swap the components from side to side and the problem still remains on the right side, that eliminates those components as a suspect. What about the relay in the fuse box? That might be the next item to check, assuming that the module gets powered by just one 12v power circuit to control both the headlight and side light markers. Each of the headlight and side markers may be on their own 12v circuit as far as a source of power supply, but the module may act as an electronic relay that controls the power that flows to each bulb, and if the module itself has a relay controlling it, that could be the source of the trouble. I barely drive my A8L anymore (maybe once a month) so I never did get around to troubleshooting mine. And the few times I have driven it in the night time the headlights have stayed on.