Passenger Side Tail Light not working

dam718 · 09-07-2015, 09:59 PM

Howdy guys and gals,

I just bought a 2008 328i Sedan. It's my first BMW, so I'm still learning some things about it.

I have been going over the car trying to figure out how to solve all the service lights and such. I've got most of them resolved, and am attempting to hash out the last issue now.

The right rear trunk mounted tail light is not turning on.

So far I have replaced the bulb, moved the bulb holder to the left side (light comes on).

So I'm pretty certain it's not the bulb, or the bulb holder.

I tested the wire for +12V, and got nothing...

The wire is a Yellow with Violet going in to pin 3 of the fixture harness.

I saw a lot of folks were having issues with wires breaking in the rubber tube between the trunk and the trunk lid. I did not find any breaks.

I have since traced the wire up to the point where it enters the passenger cabin on the right side of the trunk. I have tested the continuity of the wire from the light harness to this point and there are no breaks in the wire throughout the trunk.

I haven't been able to find any good wiring diagrams, but I do have a rather basic lighting diagram from a Haynes manual that confirms the Yellow w/ Violet is the right color.

I was trying to find a source of power to this wire.

It would appear the light is connected directly to the "Footwell Control Unit"

At least from the crappy diagram I have, it looks like the Yellow w/ Violet wire comes from Pin 3 of the light harness and connects directly to harness "X14260" pin 18 of the footwell control unit.

Can anyone tell me where to locate the footwell control unit? At this point I'd like to test continuity down the entire length of the wire from the source.

Sorry for the long post... Just want to give out as much info as I can.

dam718 · 09-07-2015, 10:04 PM

Just a real quick addition to the original post.

In looking at this diagram from the Haynes manual, it would appear that this footwell control unit provides power to dang near every light on the car...

Not being familiar with the inner working of this module, is it more likely that I have a broken wire? Or that this one single output of the footwell control unit is not working? Seems like if it was something in the module, I would be seeing multiple issues...

Every other light inside and outside the car appears to be working without any issues...

uber · 09-08-2015, 02:18 AM

I am not sure if this will help, but you should check the contacts on the bulb holder. Use some sort of contact cleaner on them.

dam718 · 09-08-2015, 05:27 AM

You know, when I first started troubleshooting this issue, I found that the positive solder connection on the bulb itself had melted and the contact inside the bulb holder was very ugly. Cleaning the contact and checking continuity within the bulb holder was one of the first things I tried.

I wish it were that easy!

Thanks for the suggestion though!

dam718 · 09-09-2015, 05:28 AM

Update:

I have tested continuity from the FRM to the harness that plugs in to the light, and there are no breaks in the cable. Additionally, I have verified that the cable is not grounded out.

All signs at this point are pointing to the FRM.

Am I on the wrong track? Should I be looking at anything else before taking the car in to the dealer to have a computer diagnostic run? When the lights turn on, is there anything else that processes that signal besides the FRM? Is it possible that the FRM is fine but there is another module somewhere else in the car that is causing the problem?

Thanks!

chmsalman · 09-09-2015, 05:06 PM

Ah yes, classic FRM bullshit. I had the same issue with my driver side angel eye. You need to purchase a good OBD2 to USB cable and code out the error. Basically, this is what happened:

Your bulb blew out. You didn't replace it right away. You started the car X number of times and each time, the FRM checked for errors. Each time you turned on the car, the FRM accumulated error count for that bulb. Eventually it got fed up (hot headed Germans) and assumed you already tried changing the bulb and considered it to be an "internal fault". To protect one thing or another, it decided to shut power to that light.

Result:

A permanent error code associated with that light which cannot be cleared using a simple OBD diagnostic/reset tool.

Frustration.

I could easily clear the code for you, but I live in the middle of nowhere in Canada so there are a few options for you. Go to the stealership, pay a diagnostic fee although you already know what's wrong and then pay more to get it fixed. OR, don't pay the diagnostic fee, tell them they need to reset the error counter on the FRM, pay them like $300 to do it. They probably won't get it because most of them are totally incompetent when it comes to coding the car, and they won't give you your money back because they didn't do any "diagnostics" and they'll assume you didn't know what you were talking about, your fault.

Another option, buy the cable and software, DIY. Another option: buy the cable and software and I can connect to your computer remotely and code it. Last option, PM me for another option lol.

dam718 · 09-10-2015, 10:00 AM

Quote:

Originally Posted by chmsalman

Ah yes, classic FRM bullshit. I had the same issue with my driver side angel eye. You need to purchase a good OBD2 to USB cable and code out the error. Basically, this is what happened:

Your bulb blew out. You didn't replace it right away. You started the car X number of times and each time, the FRM checked for errors. Each time you turned on the car, the FRM accumulated error count for that bulb. Eventually it got fed up (hot headed Germans) and assumed you already tried changing the bulb and considered it to be an "internal fault". To protect one thing or another, it decided to shut power to that light.

Result:

A permanent error code associated with that light which cannot be cleared using a simple OBD diagnostic/reset tool.

Frustration.

I could easily clear the code for you, but I live in the middle of nowhere in Canada so there are a few options for you. Go to the stealership, pay a diagnostic fee although you already know what's wrong and then pay more to get it fixed. OR, don't pay the diagnostic fee, tell them they need to reset the error counter on the FRM, pay them like $300 to do it. They probably won't get it because most of them are totally incompetent when it comes to coding the car, and they won't give you your money back because they didn't do any "diagnostics" and they'll assume you didn't know what you were talking about, your fault.

Another option, buy the cable and software, DIY. Another option: buy the cable and software and I can connect to your computer remotely and code it. Last option, PM me for another option lol.

You nailed exactly what the problem ended up being.

I ended up just taking the car in to the dealership. I was prepared to buy a new FRM... When they took it back, about 30 minutes later the tech came in and basically explained to me exactly what you just said here.

They charged me a diagnostic fee, and the resetting the FRM was included in the fee. Unfortunately they charge a minimum 1 hour fee, so I had to pay $144.95 US.

Oh well... In the end it was a lot cheaper than a new FRM. Guess I should look at getting one of these ODB2 to USB interfaces...

chmsalman · 09-10-2015, 04:29 PM

Quote:

Originally Posted by dam718

You nailed exactly what the problem ended up being.

I ended up just taking the car in to the dealership. I was prepared to buy a new FRM... When they took it back, about 30 minutes later the tech came in and basically explained to me exactly what you just said here.

They charged me a diagnostic fee, and the resetting the FRM was included in the fee. Unfortunately they charge a minimum 1 hour fee, so I had to pay $144.95 US.

Oh well... In the end it was a lot cheaper than a new FRM. Guess I should look at getting one of these ODB2 to USB interfaces...

Got it fixed under $150? not too bad... haha im glad it worked out for you.

johnbradshow · 09-10-2015, 06:12 PM

I am so glad that I found this since I had the same issue a few weeks ago and thanks for you guys for this advice, my BMW tail lights are all working now. But I did end up upgrading them to aftermarket LED tail lights at http://www.xtralights.com/all-produc...ail-lights/bmw

I installed them a few days ago and they work great so far, I really love the new look of them.

09-07-2015, 09:59 PM	#1
dam718 New Member 3 Rep 10 Posts Drives: 2008 328i Join Date: Sep 2015 Location: Atlanta iTrader: (0)	Passenger Side Tail Light not working - Need assistance! Howdy guys and gals, I just bought a 2008 328i Sedan. It's my first BMW, so I'm still learning some things about it. I have been going over the car trying to figure out how to solve all the service lights and such. I've got most of them resolved, and am attempting to hash out the last issue now. The right rear trunk mounted tail light is not turning on. So far I have replaced the bulb, moved the bulb holder to the left side (light comes on). So I'm pretty certain it's not the bulb, or the bulb holder. I tested the wire for +12V, and got nothing... The wire is a Yellow with Violet going in to pin 3 of the fixture harness. I saw a lot of folks were having issues with wires breaking in the rubber tube between the trunk and the trunk lid. I did not find any breaks. I have since traced the wire up to the point where it enters the passenger cabin on the right side of the trunk. I have tested the continuity of the wire from the light harness to this point and there are no breaks in the wire throughout the trunk. I haven't been able to find any good wiring diagrams, but I do have a rather basic lighting diagram from a Haynes manual that confirms the Yellow w/ Violet is the right color. I was trying to find a source of power to this wire. It would appear the light is connected directly to the "Footwell Control Unit" At least from the crappy diagram I have, it looks like the Yellow w/ Violet wire comes from Pin 3 of the light harness and connects directly to harness "X14260" pin 18 of the footwell control unit. Can anyone tell me where to locate the footwell control unit? At this point I'd like to test continuity down the entire length of the wire from the source. Sorry for the long post... Just want to give out as much info as I can.
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09-07-2015, 10:04 PM	#2
dam718 New Member 3 Rep 10 Posts Drives: 2008 328i Join Date: Sep 2015 Location: Atlanta iTrader: (0)	Just a real quick addition to the original post. In looking at this diagram from the Haynes manual, it would appear that this footwell control unit provides power to dang near every light on the car... Not being familiar with the inner working of this module, is it more likely that I have a broken wire? Or that this one single output of the footwell control unit is not working? Seems like if it was something in the module, I would be seeing multiple issues... Every other light inside and outside the car appears to be working without any issues...
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09-08-2015, 02:18 AM	#3
uber uber driver 120 Rep 657 Posts Drives: 2011 335i E90 Join Date: Jan 2013 Location: Bay Area iTrader: (5)	I am not sure if this will help, but you should check the contacts on the bulb holder. Use some sort of contact cleaner on them.
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09-08-2015, 05:27 AM	#4
dam718 New Member 3 Rep 10 Posts Drives: 2008 328i Join Date: Sep 2015 Location: Atlanta iTrader: (0)	You know, when I first started troubleshooting this issue, I found that the positive solder connection on the bulb itself had melted and the contact inside the bulb holder was very ugly. Cleaning the contact and checking continuity within the bulb holder was one of the first things I tried. I wish it were that easy! Thanks for the suggestion though!
	Appreciate 0 Quote

09-09-2015, 05:28 AM	#5
dam718 New Member 3 Rep 10 Posts Drives: 2008 328i Join Date: Sep 2015 Location: Atlanta iTrader: (0)	Update: I have tested continuity from the FRM to the harness that plugs in to the light, and there are no breaks in the cable. Additionally, I have verified that the cable is not grounded out. All signs at this point are pointing to the FRM. Am I on the wrong track? Should I be looking at anything else before taking the car in to the dealer to have a computer diagnostic run? When the lights turn on, is there anything else that processes that signal besides the FRM? Is it possible that the FRM is fine but there is another module somewhere else in the car that is causing the problem? Thanks!
	Appreciate 0 Quote

09-09-2015, 05:06 PM	#6
chmsalman First Lieutenant 48 Rep 357 Posts Drives: 2014 F10 535i x-drive Join Date: Jun 2013 Location: Regina, CA iTrader: (0)	Ah yes, classic FRM bullshit. I had the same issue with my driver side angel eye. You need to purchase a good OBD2 to USB cable and code out the error. Basically, this is what happened: Your bulb blew out. You didn't replace it right away. You started the car X number of times and each time, the FRM checked for errors. Each time you turned on the car, the FRM accumulated error count for that bulb. Eventually it got fed up (hot headed Germans) and assumed you already tried changing the bulb and considered it to be an "internal fault". To protect one thing or another, it decided to shut power to that light. Result: A permanent error code associated with that light which cannot be cleared using a simple OBD diagnostic/reset tool. Frustration. I could easily clear the code for you, but I live in the middle of nowhere in Canada so there are a few options for you. Go to the stealership, pay a diagnostic fee although you already know what's wrong and then pay more to get it fixed. OR, don't pay the diagnostic fee, tell them they need to reset the error counter on the FRM, pay them like $300 to do it. They probably won't get it because most of them are totally incompetent when it comes to coding the car, and they won't give you your money back because they didn't do any "diagnostics" and they'll assume you didn't know what you were talking about, your fault. Another option, buy the cable and software, DIY. Another option: buy the cable and software and I can connect to your computer remotely and code it. Last option, PM me for another option lol.
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09-10-2015, 06:12 PM	#9
johnbradshow Enlisted Member 5 Rep 45 Posts Drives: I have brand new Audi R8 Join Date: Jul 2015 Location: USA iTrader: (0)	I am so glad that I found this since I had the same issue a few weeks ago and thanks for you guys for this advice, my BMW tail lights are all working now. But I did end up upgrading them to aftermarket LED tail lights at http://www.xtralights.com/all-produc...ail-lights/bmw I installed them a few days ago and they work great so far, I really love the new look of them.
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