[Di3s3l_Power]

Originally Posted by marcelji

Di3s3l_Power Thanks for the detailed pics on the Redarc install.

Did you you need to install the Redarc diode?
(https://www.redarcelectronics.com/us...ed-power-diode)

After installing my Redarc Tow-Pro Elite I'm receiving a center brake light malfunction warning on my car. I believe pressing the manual override button of the Redarc is causing the brake lights to backfeed the system. Just wondering if you ran into this problem. I believe the diode was designed to fix this problem, but installing the diode would require knowing where the center mount height stop light (CMHSL) wire is.

I haven’t installed the Redarc diode. In fact, I didn’t get a chance to test with trailer (as is in storage until April 1st)

I might encounter the same issue, I will reply to this thread if so.

I intend not to use the manual override, just proportional braking

[marcelji]

Di3s3l_Power Whether or not you run into the issue might depend on what year your X5 is. I have a feeling I'm running into this issue because mine is 2023.

I spoke to someone at Tekonsha support today and told them I bought the 3037-P harness expecting it to be plug and play for the X5. They said that the issue I'm having is most likely because I don't have a diode in place and the brake lights are backfeeding the braking system, as I expected.

They said the 7865 harness (https://www.tekonsha.com/Product/786...ontrol-harness) has a diode built into the red brake wire, so that's what I would need. Only issue is that the 7865 doesn't have the BMW connector on it. My plan is to cut off the BMW adapter from the 3037-P and wire it to the 7865 harness and connect it to the Redarc. Tekonsha is sending me the 7865 harness for free, as they said they weren't aware of this issue with the newer X5. I'm guessing they will create a version of the 3037-P with a diode eventually.

I also hope to never have to use manual override but it's a safety feature. If the trailer starts to sway out of control, pushing that button alone will help straighten out the trailer and tow vehicle.

[jad03060]

FWIW, the built-in anti-sway logic in the OEM towing package can activate the trailer's brakes on its own, so, in most cases, a manual override (should) never be needed.

[Di3s3l_Power]

Originally Posted by marcelji

Di3s3l_Power Thanks for the detailed pics on the Redarc install.

Did you you need to install the Redarc diode?
(https://www.redarcelectronics.com/us...ed-power-diode)

After installing my Redarc Tow-Pro Elite I'm receiving a center brake light malfunction warning on my car. I believe pressing the manual override button of the Redarc is causing the brake lights to backfeed the system. Just wondering if you ran into this problem. I believe the diode was designed to fix this problem, but installing the diode would require knowing where the center mount height stop light (CMHSL) wire is.

I don’t have this issue.

One surprise was the unit had to run a calibration cycle when I first hooked up the trailer. The instructions says it calibrates automatically with or without trailer.

The unit calibrated within first 5 minutes, I think is around 20 brake applications.

[skarimi]

Originally Posted by Tallman152

A few more pics of the wiring and mounting.

Thank you for the detailed pictures. While I had the same idea, seeing your pictures confirmed my thoughts that this is possible.

I went a slightly different route though and mounted the snap-in bracket from the top using double-sided 3M tape. I can un-snap the controller from the bracket and leave it in the closed compartment.

The only modification to the stock part that I did was creating a small opening at the back for the wires. Since I inserted the pins in the connector later, I only needed a small hole for wires to go through.

[bono]

What is the source of this information? It would be great, if this works like that. I am skeptical to be honest. I thought that BMW anti sway software controls only vehicle brakes, not trailer.

Originally Posted by jad03060

FWIW, the built-in anti-sway logic in the OEM towing package can activate the trailer's brakes on its own, so, in most cases, a manual override (should) never be needed.

[jad03060]

With an electronic brake controller, if the brake lights come on, it should activate the trailer brakes at the same time. With surge brakes, the slowing of the vehicle should apply the trailer brakes...no help if the trailer doesn't have brakes. Now, the questions is, does the vehicle's stability control, when it applies the brakes, turn the brake lights on? I think so. The user's manual says it applies the vehicle's brakes, so that leaves it somewhat up in the air. IMHO, it would be bad practice to be applying the brakes and not activate the lamps as well.

The Autowbrake controller has its own accelerometers in it and can brake the trailer independently if it detects the advent of sway in addition to the normal braking when the tow vehicle's brakes are applied. FOr this reason, I'm leaning toward that controller if I buy one.

[Celos]

I installed a Prodigy iD brake controller in my 2023 45e. Following the inspiration of others in this thread, I put it in the left-hand cubby and used the connector available from ECS Tuning to connect the vehicle harness to the brake controller.

It’s mounted in such a way that I can reach it while driving if I need to apply the manual override. It’s a little too far of a reach, so I’m going to move the mount further forward in the drawer, and may also change the angle of the mounting plate to make it easier to reach. I tried another position, hence the extra drill holes in the last photos.

The Prodigy iD brake controller has a controller box that plugs into the car harness on one side via a pigtail connector from Tekonsha, and plugs into the the controller knob on the other side.

I put the box behind the dash (details below) and the controller knob in the cubby.

A few notes from the install.

Removing the cubby is pretty easy. It has two T20 torx screws on the top, and a couple clips on the bottom. Once the screws are out, it pulls straight out. It looks like this when it’s removed (clips visible at the bottom).



Removing the bottom plate below the steering wheel was helpful, but honestly there’s more room to work reaching in through the cubby. Even if you’re not going to install the brake controller in the cubby, removing it to have room to work is helpful. You can see the brake controller factory connector in these photos.





The bottom plate below the steering wheel/dash remains attached due to some wiring connectors that I couldn’t seem to detach. The sun was shining directly in the car door so the photos aren’t great.



Taking the cubby apart allows for drilling and trimming. The door catch just needs to be pushed in from either side to get it apart.





Per post 61 in this thread, I bought the connector and pins from ECS Tuning, and connected them to the pigtail from Tekonsha.

Thanks to this post, I called Tekonsha to ask about the need for a harness with a diode. The person I spoke to cheerfully told me they had no information on BMW X5s, so I just went ahead and bought the 7865 harness as I needed a pigtail for the brake controller anyways.

The Tekonsha harness wires are not all the same gauge, and the thicker ones were a little tricky to fit in the pins from ECS, but they did fit.

The wires on the X5 side of the brake controller harness are all the same gauge. I couldn't figure out any way around that fact. Since the majority of the current is coming from the vehicle side of the harness, not the controller, I decided it was going to be fine. You can see the difference in the gauge in this photo.



Mapping the X5 wires to the harness wasn’t too hard thanks to this thread.



Once wired up, the pins clip into the ECS-provided harness, which in turn connects to the factory harness. It's relatively easy to unclip the Tekonsha harness from the X5, if I ever wanted to remove it for some reason.



I mounted the controller box on top of the knee airbag housing with double-sided velcro tape.



Closeup:

And mounted the control knob to an aluminum plate that I attached to the cubby with angle brackets.







Per the comment from @[jad03060], the built-in sway control seems to work really well. I used the manual override a couple times on my 2,000 mile trip to the Grand Canyon, but quickly realized it wasn’t really needed. It’s nice to know the option to straighten out or slow down the trailer is there, but compared to my previous vehicle, where I needed to apply the trailer brakes manually pretty frequently, the X5 does very well. I didn't do enough mountain passes on this trip to know whether setting the boost level on the trailer brakes for long downhills will be helpful or necessary in the X5. I will post some impressions of the X5 as a tow vehicle overall (and how the hybrid works as a tow vehicle) in another thread.

To clarify what the built-in anti-sway does, though, it brakes the vehicle, not the trailer, per the manual:



I had no way to verify that the trailer brakes or brake lights were activated when the X5 trailer stability kicks in. But I don’t think they likely are, based on the way the trailer behaved. It felt much more like the car was braking than the typical “pulling” motion I’m used to when using the manual override.

Tekonsha actually sold (it’s not on their site anymore) a wiring harness specifically to turn on the trailer brake lights if the manual override was used (link on etrailer).

[jad03060]

If the vehicle does not activate the brake lights when it initiates the stability control, then it won't do anything to the trailer brakes (at least with an electronic brake controller).

This is why I'm leaning towards the AutoTowbrake box...it detects the sway and can activate one or both of the trailer brakes on its own, maybe before the X5 would detect the situation developing. As I mentioned, it wouldn't be all that useful if you towed multiple trailers unless you put one on each...that would get expensive, but may be nice if you loaned the trailer to someone that had the hitch, but not the controller...it is IN the trailer, so will work with or without one in the vehicle.

[bono]

Where does it state that it will activate trailer brakes when it detects sway? I am not familiar with this product. I am using Tekonsha Prodigy RF (wireless) for the last 40k towing miles. It auto brakes, i.e. the controller in the cabin may not work, but it will still brake the trailer. However, it won't specifically fight sway. I doubt that AutoTowbrake will do this either.

If somebody is serious about towing, ProPride hitch eliminates sway. Expensive, but works very well.

Originally Posted by jad03060

If the vehicle does not activate the brake lights when it initiates the stability control, then it won't do anything to the trailer brakes (at least with an electronic brake controller).

This is why I'm leaning towards the AutoTowbrake box...it detects the sway and can activate one or both of the trailer brakes on its own, maybe before the X5 would detect the situation developing. As I mentioned, it wouldn't be all that useful if you towed multiple trailers unless you put one on each...that would get expensive, but may be nice if you loaned the trailer to someone that had the hitch, but not the controller...it is IN the trailer, so will work with or without one in the vehicle.

[jad03060]

I just sent them an email, asking to clarify that. I know that the included fob can independently initiate trailer braking, but somewhere, I either read or saw in a video that it can do that independently...I'll update after I get a response, probably tomorrow.

If the BMW stability control logic activates the vehicle's brake lights, the trailer brakes would also be engaged. That's a question for BMW. You could probably cobble up a tap in the harness to monitor that, but then, looking at it while sway was happening may not be the safest thing to do!

The tech from AutowBrake got back to me...good response time...a couple of hours and it was after normal working hours. They are working on self-contained anti-sway logic, but it is not in the current units, so I was misled thinking it was already implemented. When you manually engage the brakes, it's done more like ABS, where it pulses the brakes to try to stop the sway of the trailer rather than a fixed value.

[Celos]

What's being towed also makes a big difference. I have a low-profile trailer that weighs less than 2,000 pounds (~900 kg). It also has a pretty low hitch weight (~200 pounds/90kg).

So I tow with a regular hitch as I don't need weight distribution, and I used an older Tekonsha brake controller for years in my previous vehicle. In that car I definitely needed the manual override, which applies the brakes up to a maximum percentage that you can set.

I was going to just move that controller over to the X5, but realized it doesn't work properly when it's tilted down as it needs to be in the cubby.

If you're towing something heavier, taller, or longer then a different brake controller or hitch may be warranted. And, of course, all the usual caveats about driving within the limits of the tow vehicle and trailer combination apply. Keeping the speed down and being aware of things that might impact the trailer (passing large trucks, crosswinds, mountain grades, etc.) makes a big difference.

[bono]

All good points here. I am pushing the limits of X5, therefore, I am using the best hitch on the market (ProPride). X5 handling and the hitch provide one hand driving experience even when towing a 33' trailer.

[JohnSEA]

Originally Posted by Di3s3l_Power

I'm adding this post and photos to help others who want to go with wired trailer brake controller (g05 X5 with towing package)

Some summary from previous posts:

The pin out of the connection from BMW connector is as follows:

Brown = Ground
Blue = To trailers brakes
Red w/stripe = +12v battery
Black w/stripe = 12v brake light trigger

your brake controller connector must match the same sequence (post #54 on this thread)

I got my matching BMW pin housing and pins from ECS but you can get from other websites (pelican porsche parts). The pin housing is shared with porsche cars.

Pin housing:
Mfg Part #
99965275840
ECS Part #
ES#1512776

https://www.ecstuning.com/b-genuine-...g/99965275840/

Circular Contact 1.0mm-2.5mm:
Mfg Part #
61131376193

https://www.ecstuning.com/b-genuine-...m/61131376193/

Redarc Tow-Pro Elite Trailer Brake Controller - 2 Braking Modes - 1 to 3 Axles - Proportional

https://www.etrailer.com/Trailer-Bra...c/RED44FR.html

I used Scotch double tape Velcro (stuff that holds the I-pass on windshield) and positioned the controller horizontal. There is limited flat space to mount the controller. I used the same tape for knob controller.

Since my trailer is in storage, I followed Redarc's method of testing the brake controller. I used an old car bulb 12V 21W.
Also, there are 7-pin tester on etrailer.com if you want something already made.

https://www.redarc.com.au/how-to-test-tow-pro

These pictures and details are super helpful. For removing the panel to locate the pre-wired connector, how do you loosen it? I've turned the two "locks" CCW...anything else to loosen or remove? I don't want to force it....thanks!

[Di3s3l_Power]

Originally Posted by JohnSEA

These pictures and details are super helpful. For removing the panel to locate the pre-wired connector, how do you loosen it? I've turned the two "locks" CCW...anything else to loosen or remove? I don't want to force it....thanks!

From what I remember, once you turn CCW you gently pull out the panel. There’s sponge foam on the inside to seal and prevent rattles but should come out pretty easily.

[Colibri]

Can verify that it is still the same odd connector on my 2024. Thanks a ton to all those that got this sorted before me - very helpful.

[Colibri]

LED's on trailer --> throwing trailer malfunction warning in vehicle?

I installed the Tekonsha universal adapter (W/ DIODE) in the wiring system workaround/unique harness I built - everything is functioning as it should - brakes work, all lights properly etc. yet I'm getting a general malfunction warning in the vehicle (exact wording escapes me rn)... Again, I've checked and all lights and brakes are working as they should. So its really just an annoyance + if something should actually malfunction, it'd be nice to know it's actually real.

Coming from the motorcycle world, I've installed LED's (where OEM ECU expects incandescent), I've needed to install resistors to get the error codes to stop. I'm suspecting that's my case. (long thread here, skimmed/searched, just saw stuff on needing diode/backfeed errors - I may have missed something tho)

Anyone experience this, with LED's on the trailer, and find a solution?

[jad03060]

The solution is to add a load resister to the lamp circuits. There's a min/max on the lighting. Everything will work fine if the actual perceived load is within that range. If the load is too small, the monitoring logic won't 'see' that a bulb is lit when it is expecting it and post an error. Too large, and you'll pop a fuse.

[Colibri]

Originally Posted by jad03060

The solution is to add a load resister to the lamp circuits.

Thanks

[Rjking2112]

Hi there, lots of great info. I have a Prodigy P3 I’m moving from my old Q7 to the 2021 X5 with factory towing. I just located the factory plug under the dash. I suppose I still have to build a cable? I wasn’t sure if these are now just being sold for adapting my P3 to the factory harness. Thanks!

[Colibri]

Originally Posted by Rjking2112

Hi there, lots of great info. I have a Prodigy P3 I’m moving from my old Q7 to the 2021 X5 with factory towing. I just located the factory plug under the dash. I suppose I still have to build a cable? I wasn’t sure if these are now just being sold for adapting my P3 to the factory harness. Thanks!

AFAIK - as of 4 months ago, still had to order the parts and build the cable myself

[jad03060]

If you get a pin removal tool, it wouldn't be very hard to reorder the pinout to match your controller's needs. Cheaper than building an adapter cable.