[Alan335Xi]

Can anyone share with me the correct procedure for diagnosing "left low beam malfunction" message on the instrument cluster?
'08 335xi (E90, N54) Bi-Xennon HID with AHL.
So, I removed the the bulb thinking to swap out with the working passenger side to diagnose. Looking at the bulb, however, it looked 'cloudy' in the center. I installed a new OEM bulb and switched on the low beams. The left headlight flashed on for about a second, and promptly went out. Ugh. Removed the bulb, it too looked cloudy. So now I'm thinking voltage surge? Faulty Control Unit (car's original btw). Others on the forum must've gone through the same experience, any direction you can provide is greatly appreciated. TIA!!
Alan.

[tc535i]

HID capsules can be cloudy, that doesn't indicate a bad bulb

sounds like a bad ballast to me

[MasterWang]

I ran into the same problem yesterday.
So in OP's case, did he burn out his new OEM bulb by connecting it to a bad ballast?

[Alan335Xi]

Originally Posted by tc535i

HID capsules can be cloudy, that doesn't indicate a bad bulb

sounds like a bad ballast to me

So next step is replace ballast? Any other diagnostic or something I should be aware of?

[tc535i]

Originally Posted by Alan335Xi

So next step is replace ballast? Any other diagnostic or something I should be aware of?

sure, swap the ballasts from side to side, or test the capsule on another known working ballast. if the bulb works on another ballast and/or switching your questionable ballast to the other side and that bulb doesn't work, gives you a pretty solid case for replacement

[Alan335Xi]

Originally Posted by tc535i

sure, swap the ballasts from side to side, or test the capsule on another known working ballast. if the bulb works on another ballast and/or switching your questionable ballast to the other side and that bulb doesn't work, gives you a pretty solid case for replacement

Brilliant! Thank you.

[Alan335Xi]

Originally Posted by MasterWang

I ran into the same problem yesterday.
So in OP's case, did he burn out his new OEM bulb by connecting it to a bad ballast?

To your point, I don't know. I would hope not, otherwise how would one diagnose whether it's the bulb+igniter or the control unit as tc535i suggested to trouble shoot?
Bought an OEM Control Unit. I plan on making the switch this weekend. Now I'm nervous if a faulty bulb+igniter can damage a Control Unit and vice versa. For what they cost, I would hope the electronics have some form of self protection.
Anyone chime in?


edit: btw, what did your headlight issue turn out to be and how was it diagnosed?

[MasterWang]

Originally Posted by Alan335Xi

To your point, I don't know. I would hope not, otherwise how would one diagnose whether it's the bulb+igniter or the control unit as tc535i suggested to trouble shoot?
Bought an OEM Control Unit. I plan on making the switch this weekend. Now I'm nervous if a faulty bulb+igniter can damage a Control Unit and vice versa. For what they cost, I would hope the electronics have some form of self protection.
Anyone chime in?


edit: btw, what did your headlight issue turn out to be and how was it diagnosed?

I tried swapping the 2 bulbs then the 2 ballasts. Turns out the ballast went bad. Fortunately, the bad ballast did not burn out the bulb.

[Alan335Xi]

Success! Replaced Control Unit. Voila! Illumination. Thanks MasterWang and tc535i for the input. Commendation to Jason@Tischer for a fair price on OEM and exceptional service. Answered PM's promptly, shipped same day, received part the next.

[fazman]

Originally Posted by Alan335Xi

Success! Replaced Control Unit. Voila! Illumination. Thanks MasterWang and tc535i for the input. Commendation to Jason@Tischer for a fair price on OEM and exceptional service. Answered PM's promptly, shipped same day, received part the next.

Lol i also have a 2008 335xi e90... Mine just died as well. I'm thinking about going the ebay route for a replacement ballast. $100 used and $200 new seems the going rate. How much was it from tischer??

I'm also curious... What was the cause of the old ballast's demise? I'm still running the original battery. I also still have cpo... Does that cover the ballast???

[Alan335Xi]

Originally Posted by fazman

Lol i also have a 2008 335xi e90... Mine just died as well. I'm thinking about going the ebay route for a replacement ballast. $100 used and $200 new seems the going rate. How much was it from tischer??

I'm also curious... What was the cause of the old ballast's demise? I'm still running the original battery. I also still have cpo... Does that cover the ballast???

I would check on cpo first ... no harm. In my case, I opted for oem ($385), what's the sense getting 6 mo out of a used to go through this hassle all over again, and since the electronics seem sensitive, I didn't want to risk the false economy of blowing another bulb,control unit, or even the frm.
good luck.

[fazman]

Originally Posted by Alan335Xi

I would check on cpo first ... no harm. In my case, I opted for oem ($385), what's the sense getting 6 mo out of a used to go through this hassle all over again, and since the electronics seem sensitive, I didn't want to risk the false economy of blowing another bulb,control unit, or even the frm.
good luck.

How do i check if my frm is damaged? Usually electronics hold up well... Its not like this ballast is like the waterpump. I think its a good gamble to go used. Otherwise we would have many threads on ballast failures (i don't see it too commonly).

[Alan335Xi]

Originally Posted by fazman

How do i check if my frm is damaged? Usually electronics hold up well... Its not like this ballast is like the waterpump. I think its a good gamble to go used. Otherwise we would have many threads on ballast failures (i don't see it too commonly).

Footwell module gets input from the light switch. controls, I think, all the lights .. DRL, side lights, courtesy etc. You mentioned drl and angel eyes are ok; so i would think frm is ok. In my case, I was surprised that it turned out to be the Control Module; thought for sure the bulb after 5yrs. If you want to eliminate or confirm Contrlo Module, switch from working headlight to non-working headlight. You may also want to try a known working bulb in the non-working headlight.
Though if you are cpo, make a call and find out if you're covered if it's not the bulb.