Fix for infamous LBF problem

[mmaigret]

Hi all,

Several people have requested a write-up for this fix. Well, here it goes...

I originally intended to perform the CCM fix documented here, but found that the part number on my CCM was not the same as the one in the write-up. Therefore, I whipped out the Bentley electronic schematics and just figured out which wires went from the low beam fuses in the fuse box, through the CCM module, and out to the low beam headlight bulbs. Once I identified these four wires (two CCM inputs, two CCM outputs) I just cut them at the CCM connector, shorted them together with a molex connector, and instantly no more LBF. Unfortunately, this completely disabled the LBF feature for the low beams, so if I actually do have a low beam bulb burn out, the OBC will not tell me (it should be fairly obvious though).

Anyway, read on....

1) Remove the three screws securing the driver's side knee bolster. One on either side of the steering wheel and one down by your right shin pointing upward.





2) Loosen the bolster by pulling the center.



3) Further loosen the bolster by pulling back hard on the left side. See the clips that your are dealing with in the picture below.




4) Remove connectors for the foot light bulb, and the green thing (I think it's the warning buzzer for leaving the lights on, etc.)




5) Ok, now you can either push the bolster down and out of the way enough to work or try to figure out how to take it completely out (I couldn't figure out how to do this!).

6) Squat down low and look up under the dash near the left side for the CCM module. In front of it is a plastic nut that needs to be removed. It can be looseden either by hand or with a 10mm socket. I have big hands, so I used a socket with a 12" extension.



7) By reaching up and behind the wiring mess, attempt to pull the CCM toward you-- there is another plastic nut in the back that the module slip-fits in between. Once it's free to move to the right, you should be able to flip it over and pull it down (again, reaching up from the back). It should dangle by the connectors' wiring. In the picture below, the CCM is the black thing with the big white connector plugged into it. I had alrady done the LBF modification to my car, so you should not see any snipped wires (yet) as are shown in the picture.



8) Disconnect the big white connector by sliding the mechanism toward you. This is just to give the wires you will be working with some slack and to get the CCM module out of the way.



9) Ok, now you need to cut some wires. Look for the 4 wires that I have cut. They are all yellow with various stripes. The stripes are blue, green, grey, and red. Look at the picture below and make sure that these color wires are in the same locations as they are on my car. If so, proceed to snip them. You want to snip fairly close to the CCM module as to give you enough slack to work with, but not so close as to not be able to reconnect them should you desire to reverse the LBF fix in the future.



10) Once the wires are snipped, you want to connect the yellow/green to yellow/grey and the yellow/red to the yellow/blue all on the wiring side. See the picture of my molex connector to get the idea.



11) That's it, installation is reverse of removal (I've always wanted to write that). Please post here if you have any questions so my PM inbox doesn't overflow.

Mike

[clumpymold]

AWESOME write up! So far, the EASIEST fix I've seen and also THE best write-up I've read so far. VERY detailed and organized. Will try this once I get back on my feet. You are da man!!!

What sort of HID kit are you running?

[toddman35]

Awesome, I'm going to have to try this tonight. I assume you can get a molex connector at radio shack?

[MMNJTWA]

you my friend are a smart man... hooray for you... once i hook back up my OBC and i get this LBF reading i will do this, but luckily my HIDs do not set off the LBF (as of the last time the OBC was in my car

[CrayzeeM3]

Those look like R/C car battery connectors. You can get those at your local hobby shop. Luckily, I was a R/C enthusiast and have some lying around Ill try this soon.

[Mad Dog 20/20]

Wow. What a great write-up, and great solution.

Thanks.

[clumpymold]

Originally Posted by CrayzeeM3

Those look like R/C car battery connectors. You can get those at your local hobby shop. Luckily, I was a R/C enthusiast and have some lying around Ill try this soon.

I think those also look like computer connectors.

But I would think using typical male and female connectors would be a LOT cheaper. You can get a box of 100 for like $5.00. Plus, it won't be as bulky.

[toddman35]

Well just did the fix to my car. It was kind of a bitch to get down there (I'm a fairly big guy), but once I figured out what was going on it went pretty smooth. It's nice to turn on the headlights now without that damn low beam failure!!! You have no idea how annoying that stupid thing was. Thank you!!

[toddman35]

Originally Posted by clumpymold

I think those also look like computer connectors.

But I would think using typical male and female connectors would be a LOT cheaper. You can get a box of 100 for like $5.00. Plus, it won't be as bulky.

These are what I used. There was a huge bag of them sitting around in the shop with a $0.50 tag on them.

[DDEM3]

Hey thanks so much mmaigret, the LBF is now history

Its amazing how something so minimal can make me so happy!! Thanks alot guys!

[AntiHero]

Great writeup!!! I havent even put any time in to get annoyed by these light yet but I had it when I put in my HIDS. Now I wont even have to bother being nagged by it! Thanks alot man!

[MMNJTWA]

thats odd antihero... i didm't have the LBF... guess ou got the other 1/2 of the 50%

[BS05ZHP]

Damn! I don't even have HIDs (yet) and this is a great fix for a long time issue for many of us.

WAY TO GO!

[clumpymold]

Originally Posted by MMNJTWA

thats odd antihero... i didm't have the LBF... guess ou got the other 1/2 of the 50%

I think it probably depends on the HID kit you get. If you don't get the LBF, you're basically running higher wattage than a "typical" HID kit (or you've already got a blown OBC for that problem ). I had NO LBF error message when I was running ONE HID bulb and one stock bulb (total ~90 watts). Since stock is 110 watts, you're probably running around ~20 watts too much power.

And yes, this write-up will SURELY be put into an archive and remembered forever. In fact, this thread should be stickied for a bit. GREAT write-up!!!

[umnitza]

Originally Posted by clumpymold

I think it probably depends on the HID kit you get. If you don't get the LBF, you're basically running higher wattage than a "typical" HID kit (or you've already got a blown OBC for that problem ). I had NO LBF error message when I was running ONE HID bulb and one stock bulb (total ~90 watts). Since stock is 110 watts, you're probably running around ~20 watts too much power.

And yes, this write-up will SURELY be put into an archive and remembered forever. In fact, this thread should be stickied for a bit. GREAT write-up!!!

this is not correct.

There is NO definitive answer for why this happens - DDEM3's car is a 99 M3 with full OBC and he's running EXACTLY the same setup as I am in my car - but mine's a 98. He gets the LBF, and I don't...no matter what HID kit I put in.

We both have CATZ, but I have had access to Philips, Hella, and some other brands.

Is it resitance? Is it voltage? Is it...who knows.

Mmaigret : thank you!

[DDEM3]

Originally Posted by umnitza

this is not correct.

There is NO definitive answer for why this happens - DDEM3's car is a 99 M3 with full OBC and he's running EXACTLY the same setup as I am in my car - but mine's a 98. He gets the LBF, and I don't...no matter what HID kit I put in.

We both have CATZ, but I have had access to Philips, Hella, and some other brands.

Is it resitance? Is it voltage? Is it...who knows.

Matt is 100% correct. Unfortunatly some people just get the damn LBF and others are lucky enough to escape its evilness. It must have something to do with the sensitivity of the CCM... or atleast that would be my best guess.

Im just happy i dont have to deal with it any more! Once again thanks Mmaigret, you did a 5 star job

[mmaigret]

Hey guys. I'm glad I could help. Again, if anyone has any questions, please let me know. Also, for anyone in the Bay Area I can do the fix for you if you're not comfortable with the procedure.

[hc1001]

dumb question but, can i jus twist the wires together and then electric tape them instead of using some kind of connector? and for the white connector part... im assuming i should tape off the ends of those jus in case? is that all?

[AntiHero]

Yeh that will work. I just sautered(sp) mine together

[DDEM3]

Yeh it doesnt matter how you connect the wires together, as long as you have a good secure connection.

[mmaigret]

Originally Posted by hc1001

dumb question but, can i jus twist the wires together and then electric tape them instead of using some kind of connector? and for the white connector part... im assuming i should tape off the ends of those jus in case? is that all?

You can connect them however you want, but make sure you insulate the connection very well. Remember, these connections have peak current of ~10-12 amps! You certainly don't want to burn anything up down there.

Mike

[clumpymold]

Originally Posted by AntiHero

Yeh that will work. I just sautered(sp) mine together

It's "soldered".

[Estoril4dr]

Woohoo, just did this and no more LBF for me. The hardest part for me was getting the damn CM out. Rest was a breeze. Solder and tape.
Thanks Mike!

[CrayzeeM3]

i have some wire taps that taps two wires together at the same time. Theoretically, it would short the circuit, I wonder if this would work, if it does you dont have to snip any wires, just unsheath them a little bit. Anyone want to try?

[NiTE]

You can't just use the taps to connect the wires together unless you pull them out from the CCM as well. Plus, I think it would be a better idea to use a good set of connectors (such as the ones mmaigret used) rather than flimsy taps.