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645ci swiveling low-beams malfunctioning NEED HELP w/diagnosis & PARTS please.

2095 Views 4 Replies 2 Participants Last post by  HerbP
I have a loaded 2004 645ci convertible w/SMG & the headlights that turn with the direction you're headed. The headlights spontaneously and simultaneously stopped working. I get an error light on the dash when I try to turn them on. They don't work. Running lights work fine/side markers/halos/high beams.. everything works. It's just as if the primary headlights stopped working.

Basically I need some help diagnosing this please and what part I exactly need so that I can look it up.. or if someone knows of the part and knows a great price then that would be fabulous too!

I don't want to sound redundant here, but obviously people ask a lot of questions so i'd like to nip what i can in the bud. Yes there was some condensation in both of the lenses prior to them failing and now. Before they finally failed the headlight LED to indicate that they're on would flash when the headlights were on. At that time I noticed that they wouldn't swivel with my vehicle when it would turn, but they were working at that time. Then finally they just stopped working when i tried to turn them on, and obviously there's a notification saying something like "beam malfunction."

I don't have a diagnosis computer and visiting a dealership is not an option. Also there aren't many helpful independent service shops. Supply is low here in Buffalo so prices are high.

I'd like to address this myself. I've heard something like "actuator" needs to be replaced. I need a little more specificity please so that i'm aimed in a more specific direction.

Thank you very much. I can be reached through this thread or via call or text at 312-885-9023. My name is Scott. Thank you.
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If both your head lights have had moisture in them, there could be a lot of damage. There are 2 modules on each headlight that control the up & down movement, they are on the bottom. There are also 2 modules on the side of the headlights that control the side to side movement. These 4 modules talk to the light module, that controls all light functions. You will need to remove the front bumper cover to access the headlights. Remove the lights & find out where the moisture got in from. Hope & pray that the wiring & stepper motors inside the headlights are not fried.

You can start changing out modules hoping you guess correctly, or damage more looking for the problem. The passenger lights functions travel thru the drivers side headlight. So if the drivers side is damaged, the passenger side will not work properly. The modules are not cheap, but very cheap compared to the headlights. You could be looking at a very expensive repair, & at some point you will need the BMW software to test the modules & code them after they are installed.
Regarding the software:
Can I run the software through my Dell laptop; what's the best way to get it?
Herb, or anyone who can answer, is there a way i can bypass the directional aspect of the diagnosis and aim strictly to reactivate the lights; for function sake? I do need to look into that condensation and reseal these lights, but I would REALLY like to get them simply working for the time being... Any way I can give that a shot?
If the lights are aiming straight, they will operate without doing anything. If the stepper motors are cocked to the side, you probably have shorted out the internal wiring inside the headlights themselves. If the wiring is bad inside the headlights, you have damaged some of the 5 modules. Without the software to test what the problem is, there is not anything else you can do but remove the lights & inspect for obvious problems.
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