[exoray]

My car’s passenger low beam went out so I replaced it with a new one and it still didn’t turn on. I thought it might be a short circuit counter issue since I put this repair aside for a bit and strangely the counter is at 0. The strangest part is that it’s only the low beams. Hi-beams and halos work fine. Anyone have an idea of what it could be besides the bulb and software?

[Serf27]

A break in the wire. Or bad ballast if the light is xenon.
What year and model? Xenon or halogen?

[exoray]

Originally Posted by Serf27

A break in the wire. Or bad ballast if the light is xenon.
What year and model? Xenon or halogen?

2008 335i(only sold with Xenon). I'm suspecting it's the ballast. Passenger side too so I'm probably going to have to take the bumper off and pull the whole assembly. I love this car but damn, why they gotta package their cars like this

[Serf27]

The high beam and low beam use the same bulb and ballast.
Your high beams turn on if you push the stalk forward?

[exoray]

Originally Posted by Serf27

The high beam and low beam use the same bulb and ballast.
Your high beams turn on if you push the stalk forward?

Yup… so if we rule out the ballast, what could it be making only the low beam to not turn on? It’d have to be somewhere after the ballast?

[Serf27]

You say high beam(s) and low beam (s). Is it both sides or just the passenger?
The ballast connects to the bulbs with its own wire harness, that is replaceable.
That’s the only thing after that ballast and then the bulb.
I believe that harness has 3 wires, possible the low beam wire in the harness is broken?

I am also not sure how the ballast works internally. The high beam part of the ballast could be working but the part that controls low beams not work…?

Did you reset the short circuits even though the counter was at 0?

Do you have any faults for low beam malfunction?
Ballasts and bulbs are cheap on Amazon. Aftermarket of course, but I haven’t had issues with them so far.

[exoray]

Originally Posted by Serf27

You say high beam(s) and low beam (s). Is it both sides or just the passenger?
The ballast connects to the bulbs with its own wire harness, that is replaceable.
That’s the only thing after that ballast and then the bulb.
I believe that harness has 3 wires, possible the low beam wire in the harness is broken?

I am also not sure how the ballast works internally. The high beam part of the ballast could be working but the part that controls low beams not work…?

Did you reset the short circuits even though the counter was at 0?

Do you have any faults for low beam malfunction?
Ballasts and bulbs are cheap on Amazon. Aftermarket of course, but I haven’t had issues with them so far.

So I have all the lights except for my passenger low beams. I’ll try to buy a ballast to see if the high and low beam are independent within the ballast since I’ve already replaced the bulb. If the ballast doesn’t fix it I’ll replace the low beam wiring

I reset the counter as well and only the A8AB code from the frm is thrown

[Serf27]

You can test for continuity on that small wiring harness in the headlight when you remove the light.

[exoray]

Originally Posted by Serf27

You can test for continuity on that small wiring harness in the headlight when you remove the light.

There's four pins I think that go into the harness. Do you know which one's ground and power?