Electric Brake Controller

DaveNW · #1 11-07-2007, 03:53 AM

Hi everyone,

New member here. Just bought an '03 X5 4.4i a few weeks ago. Absolutely love the truck, and I'm working hard to "make it my own." I gave up an '04 325i convertible to buy it, and so far, I have no regrets.

I'm trying to resolve a very specific situation, and hope those of you with more experience will be able to help me out:

I've searched high and low for a definitive answer about installing an electric brake controller. The size and weight trailer I'm hauling requires one. I've read the two "how-to" posts here at X5World about installation, but I'm trying to find out exactly what parts are needed, how many of them are OEM, and what exactly is needed to make this work. The biggest questions are about where to connect the wiring to the unit to get proper performance.

I spoke to my local dealer (BMW Seattle) and got nowhere. I called BMW USA today, and the rep I spoke with was genuinely suprised to learn BMW doesn't offer a brake controller, and doesn't even recommend one, even though the OEM hitch installation instructions advise the installer to call BMW Service for recommendations on what to use. He had no answer when I asked why BMW would make a vehicle that is rated to tow 6000 pounds, and even provides an OEM Class III hitch, but then can't tell me the right way to install a brake controller that a large trailer would require. The trailer dealer that installed a brake controller on my previous tow vehicle told me there are a number of vehicles they won't install brake controllers on, and BMW heads that list. This has been a very frustrating search.

I've had an OEM BMW hitch installed by a reputable local company. They did a great job, but they can't install a brake controller without having the right parts, and knowing the best way to connect it. Due to the X5's brake system, a conventional connection doesn't work.

So what I'm trying to find out is what do YOU have? If you have a brake controller installed in your X5, how is it connected? What parts did you use? Was your BMW dealer involved, or was it totally after market? Has anyone made a direct installation kit with the right parts in it? Or is there a perfect "how-to" somewhere that I can provide to the installer? If not, is anyone here from the Seattle area who can refer me to an independent shop that knows how to properly install a brake controller? I want my X5 to have a long and happy life, and I really don't want to make a mess of thigns by some kind of jury-rigged installation. I need this to be done right.

Can anyone help me out? I'd sure appreciate it. Thanks very much in advance.

Dave

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mfiver · #2 11-07-2007, 10:55 AM

Hello Dave,

I'm going to install my brake contoller this weekend, so I have just finished all the research myself. I recommend the Tekonsha Prodigy controller, if you haven't already purchased one. I used the Prodigy on my last truck and it was truly awesome!

I've done these installs before and they are an easy project for any do-it-yourselfer using the following instructions:

There are two excellent write up's for installing the controller located on the home page of this site -
http://www.bmwmotorsports.org/pdf/BM...er%20Brake.pdf
http://www.bmwmotorsports.org/pdf/X5...stallation.pdf

The wiring is straight forward (to anyone who has done this type of thing before), and there is only one aspect of the installation unique to the X5 - picking off the 12V brake signal. That connection is described from BMW here:

"A connection pin for retrofitting (electric brake) is provided on
plug X393S. If an electrical brake is desired for the trailer, it
can be retrofitted. For the latest list of recommended brake
controllers contact BMW Service Hotline. The signal pick-off for
brake (the input to the brake controller) may only take place on
plug X12, Pin 10. This plug, X12, is to the Light Control Module
(LCM), the wire color is black and yellow. The male pin (BMW
P/N 61 13 1 376 195) should be used at the mating plug of
X393S. Be sure to observe this information."

In addition to your brake controller kit, the BMW OEM tow kit, and misc wires and connectors (that any installer would already have), you only need two additional pieces of hardware: 1) a BMW male pin P/N 61 13 1 376 195 2) a 20A-30A resettable circuit breaker - available at any stereo and most auto parts shops.

So here is the readers digest version of the install:

1) pick your controller location - left of sterring wheel or inside ash tray
2) black and white wires (power and ground) to the battery
3) blue wire to the rear trailer connector
4) red brake signal wire to the LCM (light control module behind the glove box)
5) Done!

Simple, no?

Good luck, let us know how it goes!

4MoJoe · #3 11-07-2007, 11:59 AM

I've done this with the Prodigy and basically the same install instructions. I mounted my controller just above the dead pedal on the left hand side of the drivers side. Towed our boat for 2 seasons using this and it works perfectly. With the prodigy I can disconnect it from the wiring simply and remove it when not in use.

The articles mentioned above are great documentation and just give yourself an afternoon to do the install.

It's nutty that BMW hasn't addressed the brake controller issue. The big 3 have done this for years and Toyota too with the Tundra and they make it so easy to install a brake controller. Hello! BMW are you listening?

DaveNW · #4 11-07-2007, 06:38 PM

Thanks for the replies. The two articles mfiver mentioned are the two I was referring to. After reading through them again, I think this is a doable thing. My installer guy is willing to try, anyway, as long as I can give him as many OEM parts as possible.

So that begs the question: Are brake controllers that different from each other? Why choose a Tekonsha Prodigy controller? I grant they're great for all-purpose trailer brake controlling, but isn't it a bit of overkill for occasional use of one trailer type? Is there an advantage of specifically using the Prodigy, instead of another Tekonsha model or a different brand altogether? It seems virtually every article I've read mentioned the Prodigy, but nobody ever says why they chose it. And why am I seeing that the controller should be mounted as horizontal as possible? Why would it matter?

Thanks,
Dave

X5 in AK · #5 11-07-2007, 06:46 PM

My understanding for using the Prodigy controller on the X5 is due to the method required of picking up the brake light signal. As the brake lights are triggered by a hall effect sensor on the pedal (as opposed to the usual method of a mechanical switch) you can't just tap into the sensor like you do on most vehicles. You are picking up the signal on from that 'pin 12' over in the passenger footwell area. Not sure what the exact reason is, but it has been determined from trial and error by other people that the Prodigy is the only controller that works in the X5 without screwing something up.
I haven't installed one yet, but it is on my list, just haven't gotten around to it yet.

mfiver · #6 11-07-2007, 07:18 PM

Quote:

Originally Posted by jeepguynw

Thanks for the replies. The two articles mfiver mentioned are the two I was referring to. After reading through them again, I think this is a doable thing. My installer guy is willing to try, anyway, as long as I can give him as many OEM parts as possible.

So that begs the question: Are brake controllers that different from each other? Why choose a Tekonsha Prodigy controller? I grant they're great for all-purpose trailer brake controlling, but isn't it a bit of overkill for occasional use of one trailer type? Is there an advantage of specifically using the Prodigy, instead of another Tekonsha model or a different brand altogether? It seems virtually every article I've read mentioned the Prodigy, but nobody ever says why they chose it. And why am I seeing that the controller should be mounted as horizontal as possible? Why would it matter?

Thanks,
Dave

Everyone uses the Tekonsha Prodigy because it's the very best, or at least the very best for the buck. It uses a sophisticted inertial system to measure the actual g-force generated during braking and applies power to the trailer brakes in proportion to the vehicle's deceleration. In plain terms - the harder you brake your X5, the harder the Prodigy brakes your trailer. Simple, but genius! Another outstanding feature of the Prodigy is that it is self-leveling. So it is not as sensitive to istallation angle as other old style controllers. It also adjusts itself to varying terrain as you drive, so if you are braking on a down hill it will still measure true deceleration force (i.e. the same value that would be measured if the car and the controller were both perfectly level.)

Back to why everyone uses Prodigy... It's cheap, it's an outstanding product, and BMW owners are willing to pay more for quality. I got mine brand new on e-bay for about $79. Sure you could get a vastly inferior controller for $50 or $60, but why would you? To save $20 or $30? That would be like buying a Kia Sportage instead of an X5 to save $500!

I think there is a lot unecessary aniexty over installing a brake controllers on an X5. There is only one piece of information we need to know that is different than any other vehicle...and that is - Where to pick up the 12 volt brake signal?? Once we know that answer to that question (and we do - it's plug X12 Pin 10 on the LCM) installing the controller on the X5 is just as easy as any other vehicle (that is not pre-wired for a brake controller). Once you know where to pick-up the 12 volt brake signal, any stereo installer, auto tech, or do-it-yourselfer can easily do it with or without the instructions on this site.

And feel free to use any brake controller you want as long as it takes a 12 volt trigger signal. But why not go for the best, and therefore the safest, for only $20 or $30 more?

mfiver · #7 11-08-2007, 02:53 AM

I was able to obtain the schematic for LCM plug X12 to be used for the brake signal pick-off. With this descrpition and the attached diagram it should be easy for any installer to find the correct connection point.

"A connection pin for retrofitting (electric brake) is provided on
plug X393S. If an electrical brake is desired for the trailer, it
can be retrofitted. For the latest list of recommended brake
controllers contact BMW Service Hotline. The signal pick-off for
brake (the input to the brake controller) may only take place on
plug X12, Pin 10. This plug, X12, is to the Light Control Module
(LCM), the wire color is black and yellow. The male pin (BMW
P/N 61 13 1 376 195) should be used at the mating plug of
X393S. Be sure to observe this information."

DaveNW · #8 11-08-2007, 01:28 PM

Thanks again for the replies. Nothing like hearing the voice of experience.

I completely agree with the Prodigy as being the right choice. The cost savings of a few dollars wasn't my concern - I was more interested in knowing why THAT particular controller was so popular, and nobody ever said anything about another model or brand. The installation company I used to put in my OEM hitch happens to be a Tekonsha dealer, and the owner (my installer) was the one who asked the "Isn't a Prodigy kind of overkill for what you need to do?" question.

As it happens, my installer is also a real pro at what he does. I took the install instructions referenced above to him yesterday, and we discussed what he would do. Once he understood why the X5 is different than other cars, he said, "Actually, this install is more like it used to be, before cars were so complicated. It'll be a piece of cake." So, armed with the OEM pin part I had ordered (which looks surprisingly like the pin shown in the installation instructions already mentioned) he's confident he'll be able to do a fine job.

I'll report back once everything is done, and put together that definitive how-to I was looking for. Maybe the X5World moderators can offer it to those like me who were looking for a "final answer" about this. (I'm still amazed after this many X5 years that BMW hasn't stepped up with a suitable controller and installation instructions that tell folks exactly what to do.)

Thanks again for all the great info. You guys rock!

Dave

davidachoi · #9 02-24-2008, 02:40 PM

I'm a little late with this thread, but this info is really helpful. So, what is this OEM part that I need to install the Prodigy? I know mfiver had the instructions about parts and all that, but that might as well been in Chinese, I didn't understand a thing in that. If I wanted to buy everything online, what should my order look like to install this brake contoller? I'm not very handy, should I get a pro to do this?

JCL · #10 02-24-2008, 02:52 PM

Quote:

Originally Posted by davidachoi

I'm a little late with this thread, but this info is really helpful. So, what is this OEM part that I need to install the Prodigy? I know mfiver had the instructions about parts and all that, but that might as well been in Chinese, I didn't understand a thing in that. If I wanted to buy everything online, what should my order look like to install this brake contoller? I'm not very handy, should I get a pro to do this?

Yes, get it professionally installed. You may also need trailer brakes installed, given the info in your other post.

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