Flickering OEM xenons ONLY when engine is running

[PipeUy]

So to give some context, a few months ago my LCM totally crapped out and I bought a used one and coded it to my car. That new to me LCM (or so I thought at the moment) caused my xenons to flicker only when the engine is running and since then I tried 2 more LCMs with the same output. I am totally baffled, the xenons work perfectly when the engine is not running but as soon as it is started they start to flicker. I tested the voltage at the headlight connector and it seems normal but I don't think my volt meter would register sudden voltage variations. Also, sometimes if I turn the fog lights on the flickering seems to stop for a while but 95% of the time it comes back later. The alternator seems to be working correctly, it was replaced about 2 years ago with a Valeo unit, and the battery is also about 2 years old. Just to make sure I will remove the battery from my E30 and try that one to make sure the E46 battery doesn't have a dead cell.

Has anyone encountered something similar?

[ugaexploder]

Both left/right headlights flicker? Not just one? Do you have any modifications to your car's electrical system? (aftermarket radio, dashcam, etc.)

[PipeUy]

Yeah both headlights flicker and the car doesn't have any mods done to the electrical system

[ugaexploder]

It might still end up being ballasts, but if both are flickering I would start with possibly a bad ground on the inner taillights? I think I've read somewhere where that was giving flicker issues on our chassis.

[PipeUy]

The weird thing is that it only happens with the engine running, they work perfectly if the engine is off, so I discarded it being ballasts, ignitors or bulbs. Yeah I heard it might be related to the taillights ground issue but I already fixed that some time ago.

[ugaexploder]

Would you have a spare set of headlights to try? Maybe it could be wiring insulation within the headlight housing that could have failed?

Also, do you ever have battery issues or do you drive regularly enough to not notice any parasitic drains? On a trickle charger and all if not used regularly?

[T.J.]

I see you have an 04, like me. There was a tsb for the ballasts and 04 was definitely an included year

[ChapterM3]

I see you have an 04, like me. There was a tsb for the ballasts and 04 was definitely an included year

Is that right? I came here to read more about this as I noticed my driver headlight flickering about a month ago, and the symptom comes and goes randomly. Sometimes it does it sometimes it doesn't and it's so incredibly slight that no one would notice except me - is this the ballast issue? and will BMW still honor the tsb?

[Slideways]

Is that right? I came here to read more about this as I noticed my driver headlight flickering about a month ago, and the symptom comes and goes randomly. Sometimes it does it sometimes it doesn't and it's so incredibly slight that no one would notice except me - is this the ballast issue? and will BMW still honor the tsb?

Always start by scanning the light control module (LCM) for codes. The next free thing to try is swapping the xenon bulbs left to right to see if the issue follows. A xenon bulb on its way out will start to flicker and eventually gets worse until it completely goes out.


OP, does your LCM register any codes?

[karter16]

Is that right? I came here to read more about this as I noticed my driver headlight flickering about a month ago, and the symptom comes and goes randomly. Sometimes it does it sometimes it doesn't and it's so incredibly slight that no one would notice except me - is this the ballast issue? and will BMW still honor the tsb?

SIB 63 01 05 - Xenon Headlamp Failure

SITUATION
Xenon light is intermittently inoperative - either one or both headlamps.

CAUSE
Faulty Xenon headlamps and control module supplied by AL (Automotive Lighting).

CORRECTION
Notes:
a. This Service Information only refers to headlamps supplied by AL (Automotive Lighting). For headlamps supplied by ZKW, carry out regular troubleshooting for the xenon system.
b. Individual parts from different manufacturers are not compatible with each other. Do not mix parts from AL and ZKW.
c. This Service Information depends on the production date of the headlamp and whether there is a green dot on the yellow parts label on the AL headlamp. The production date is shown in the format yy.mm.dd above the bar code.

Case A:
Green dot on the parts sticker on the failed headlamp, continue regular troubleshooting on the xenon light.

Case B:
No green dot on the parts sticker on the failed headlamp:

If both headlamps have failed:
The xenon control module and xenon bulb from the failed headlamps must be replaced.

If only one headlamp has failed:
Replace the xenon control module and xenon bulb from the failed headlamp. Also replace the xenon control module from the other lamp as a precautionary measure. It is not necessary to replace the xenon bulb in the other lamp.

NOTES about installing AL components (indicated by the AL suffix in the EPC):
Control unit P/N 63 12 6 907 496 - Only install a control module with a production date later than 3rd February 2005. The production date is shown in the format dd.mm.yy below the bar code on the white label.