Lowbeams not working, HELP

[hooddub]

Hey all,

Having no luck finding out what is wrong with my lowbeams.
Last night they worked fine, brand new D1S bulbs put in about a week ago, on my way to work this morning I noticed my lowbeams would not turn on.

Got home, checked the bulbs (they're fine), checked fuses (although I wasn't sure which were for my headlights as the diagram doesn't say, so I just checked all my fuses) swapped out my switch with the switch in my brother's B6, confirmed both headlight switches worked in his car and after a bit of digging I read there is no relay for B6 A4 headlights, and that they are run through the Central Electrical Control Module behind the fuse box.. $385 on ECS..

Anyone have any ideas?

[Natty54]

Re: Lowbeams not working, HELP

I would scan it and see if the module picks up anything

I can check tomorrow for fuses / relay locations

[MechEngg]

Re: Lowbeams not working, HELP

Hey Evan,

The headlights are typically going to be run directly from the CCM, through the fuse and directly out to the low beam halogen bulbs.

If they are aftermarket HID's (not sure of your setup at all) then you should run them through a relay harness, so if that is the case i'd check the relay or control module if they are bi-xenon.
If your car came stock with an HID setup and you just changed your bulbs out, i'd take a look at the ballasts, it seems quite rare to happen at the same time, but the bulbs and ballasts should typically be replaced at the same time, if new bulbs are used with an older ballasts funky things can certainly happen and it typically happens within a week or two of the install, but it only happens on one of the sides at a time. I'd check the relays, and yes there should be relays for an OEM HID harness i would believe.

[hooddub]

Re: Lowbeams not working, HELP

Hey Evan,

The headlights are typically going to be run directly from the CCM, through the fuse and directly out to the low beam halogen bulbs.

If they are aftermarket HID's (not sure of your setup at all) then you should run them through a relay harness, so if that is the case i'd check the relay or control module if they are bi-xenon.
If your car came stock with an HID setup and you just changed your bulbs out, i'd take a look at the ballasts, it seems quite rare to happen at the same time, but the bulbs and ballasts should typically be replaced at the same time, if new bulbs are used with an older ballasts funky things can certainly happen and it typically happens within a week or two of the install, but it only happens on one of the sides at a time. I'd check the relays, and yes there should be relays for an OEM HID harness i would believe.

Wow! A serious and not snarky response?? Thanks for the advice Sean!
I am going to try swapping out my brothers and my headlights tomorrow (both factory D1S Xenon) to see if it's the ballasts. If not I'm going to assume it's the CECM because I am told that there are no fuses or relays for the headlights in B6 A4/S4s oddly enough.
The CECM doesn't sound like that difficult of a thing to swap out, it just sits behind the fuse panel, just hoping I don't have to spend $400 on a new one.
I'll keep anyone who is interested updated, as I had never had this problem before and couldn't find out much about it anywhere.

[onceover]

Re: Lowbeams not working, HELP

I have a CCM

[hooddub]

Re: Lowbeams not working, HELP

I have a CCM

I can have pls

[MechEngg]

Re: Lowbeams not working, HELP

I would take a look at the following wiring diagrams (b6 a4 xenon headlamps). You do have a relay, it is just labelled as a xenon control module; So it has internal relays to fire the main low beam.
Are your turn signals working? If your turn signals are working then the problem may lie within the power going to the control module (just as you suspected). Check the voltage on wire that goes between pin T23/23 on J519 and pin 5/56b on J343 to make sure you have 12V when the beams are supposed to be on.
If your turn signals aren't working i'd check your grounds as simple as that sounds.

[MechEngg]

Re: Lowbeams not working, HELP

Also the J431 gets its power through a fuse, S10 in the engine bay. I'd check that first.

[MechEngg]

Re: Lowbeams not working, HELP

Updates?

[hooddub]

Re: Lowbeams not working, HELP

Updates?

Thanks for the suggestions Sean! Ended up just being ballasts! Didn't have to dick around with it too much. Just freaked me out because they both quit at the same time and I assumed the worst!

[bydesign]

Re: Lowbeams not working, HELP

That is really odd that they both failed at the same time. I wonder the they saw an over voltage condition or an arc to ground?

[PRY4SNO]

Re: Lowbeams not working, HELP

^^^ Good call, both at the same time is somewhat suspicious...

[MechEngg]

Re: Lowbeams not working, HELP

I third this but at the same time it has happened before. Can I ask what brand bulbs you chose to replace your originals with and what condition the original bulbs were in? We're they burnt out at all or did you just want a change in color?
Using aftermarket hid bulbs paired with oem ballasts which have been used for quite a while seems to put a lot of strain on the ballasts. Don't ask me for the technical reasoning why, it just seems to happen that way. The worst pairing between aftermarket vs oem ballasts and bulbs is the oem used ballasts with aftermarket new bulbs. Best is to pair oem with oem or aftermarket with aftermarket. Oem bulbs with aftermarket ballasts is ok too, provided that they are both brand new.
again it may seem like a weird science, but it has quite a bit of backup if you know what you are searching for.

[onceover]

Re: Lowbeams not working, HELP

Good thing you sold that POS hey?