Installing Electric Trailer break controller: how to remove trim?
 

We just purchased Airstream sport 16 foot Trailer.

Our 12 E70 has OEM trailer hitch installed, but as always E70 still need to install the break controller to tow legally. Steallership quote $280 parts + $535 labor to install the electric Trailer break controller which is Prodigy P2 indeed. Since we already have Prodigy P2 unit passed from a friend. The only thing missing is to wire the 4 pin connecter from electric panel at rear right side of the car to the dashboard on the driver side.

I got the PDF installation guide for electric controller, it seems a fair straight DIY project, but I am not sure how to prey off all kind of trims: wheel arch trim, door pillar trim, b pillar trim, door still trim etc.

Does anyone happen to have a guide or even did so? any sugesstion is appreciated.

We are supposed to pick up the trialer on Saturday, hopefully the break controller is ready at that time.

Picture attached

Use the wireless controller. Problem solved.....

Thanks for you advise, we will try to intsall P2 first if we can, there are a few advantange of P2.

1. with P2 installed in X5, it can tow other tailers without any additional work.
2. Wireless will require to drill hole on the trialer frame to mount, which may compromise the strengh
3. Wireless has quite footprint.
4. Since we already have P2, it's duplicate investment to get Wireless

Well, I have successfully run a wire from BMW hitch harness in the back of the car to Prodigy P2 in the driver sides, it was not that hard at all. Everything works perfectly; I took some installation photos and will post them later.

Here is our my airstream

Awesome, good work and good looking trailer!

can you provide brief instructions how you removed the rear cargo area trim? Also, how did you wire it to the 4 pin connector on the trailer wire harness kit?

I noticed you have a 2012 X5, as do I... do you get an kind of special camera zoom mode when the backup camera is turned on? I have heard earlier model E70 X5's have a camera zoom and later model E70 X5's do not? I am just trying to determine if the stealer coded my hitch kit correctly, i had it done at BMW of Seattle.

Thanks for your help!

Why does the wireless "REQUIRE" drilling the frame?!?!

Presumably there were no existing holes or bolts that could be used to mount it on the trailer A-frame.

Installation pictures attached;

Our X5 does come with backup sensor but no camera, so I can't comment on zoom feature; But I know it's coded properly, when the tailer is attached, in reverse gear, a hitch icon will show up in the back of car on idrive screen, and rear backup sensor is disabled.

Tools and materials needed:
1. You need 18 feet trailer 4 wires, there is 14 gauge one you can find at Woodinville Mclendons; 12 gauge would be better, but I couldn't find locally.
2. the trim remover tool you can find at Bellevue Haborfreight.
3. P2 wire harness at Amazon, any car type less expensive is fine, you are going to cut the car adapter any way.

Installation tips:
1. You DO NOT need to remove cargo area trim and storage pocket as BMW suggested, there is enough space to push the wire through to the rear panel. Removing storage pocket requires removing two one time use plastic pivot, too much trouble to do that.
2. In order to remove rear arch trim, there are two screws need to be removed, one holds seat belt, another is hidden under rubber as in pictures.
3. Tips to remove the carpeted console trim: remove the screw holding it,
pull out front end, and then pull the trim in the direction of car.
4. Cut the P2 harness 4 pin adapter and the BMW 4 pin adapter, and hard wire them; There is no way to find 4 pin male adapter for BMW wire hardness.
5. We put the P2 on the right side under the steering wheel, it doesn't bother either my wife or me.

The whole process should be under 1 hour, and your X5 has full capability to tow after the process

Continue

wiring:

Thank you miamipanther for this detail and the awesome photos! I feel much better about wiring my prodigy brake controller.

So just to clarify... in the rear trunk, on the ride side, all i need to do is remove the "fuse panel cover (2)" per the BMW instructions above? Are you sure this will give me enough room to access that 4 pin connector so that i can cut that connector off and hardwire my prodigy? Also, does this "fuse panel cover" just come off easy without removing any screws or rivets or anything like that? that would be great!

honestly, i am not going to route all the wires through the vehicle trim, etc... i plan to just leave the brake controller in the trunk with a bunch of extra wire (like you mentioned about 18 ft) coiled up in the back with the controller. and when i'm towing (not very often) - i'll just grab the brake controller and bring it to the front of the car and leave it "loose" just for temporary use, not worrying about the wires just running through the cabin.

so i'm hoping the access to the panel in the trunk is easy, so that i can gain access to that 4 pin and do the wiring simply.

thanks again!

Correct, you can just hand remove the fuse panel cover and the 4 pin adapter is there.

There may be safety concern to just put the P2 control in the rear trunk: There is manual break feature in the controller, it may be required by law this feature is accessable all the time.

Prodigy uses accelerometer to engage the breaks, the device need to be mounted as instructed.

You can read the votage on the controler while breaking, it's obvious whether it works or not. If you put it in the trunk, you may not know at all if it's malfunctioning.

I would highly suggest to do it in regular way.

yes, i actually plan to bring the unit forward right next to me when i'm actually trailering. if i am not trailering then i was going to just leave the whole deal in the trunk, out of sight.

but... i may just end up routing it through and mounting it up. we'll see. :)

Yeah, but as we both know that would not "require" drilling holes... I can think of more that a few ways to attach it, and question the need to install it there.

It was presented as a "requirement" as in "unavoidable" and hence a rational for running wires up to the dash....

Miami- FANTASTIC post. Really fine effort. Thx

A

Brilliant. Exactly what I was looking for. Thanks again for your documentation.

I believe he was referring to the main brain for the wireless controller. It has a large box that must be bolted to the front frame of the trailer in order for the accelerometer to work. The wireless part just plugs into the cigarette lighter and doesn't need to be mounted. I just leave mine in the center console.

I would appreciate any help here. I am installing the factory brake controller in my '09 X5. I have removed all the trim pieces and routed the wire harness up to the side of the center console.

My problem is that the PO spilled a beverage and now the access port cover under the driver's side cup holder is basically seized in place. I tried to remove it using a 1/2" drive bit, but the drive started to dig into the recess before the access port cover even moved. Any suggestions how to "un-seize" the access cover so I can route my harness?

Another question. Has anyone removed the cigarette lighter assembly to the right of the "ash tray/coin tray" and routed their brake harness that way? I think this would be a cleaner install, but access to the lighter assembly looks heinous.

Thanks in advance.

-Chris D.

Well I finished the install of my brake controller with a few caveats.
1) Routing the factory harness up through the driver's drink holder is impossible. The harness is too stiff to flex around a plastic "boss" that is right under the drink holders. I even notched the plastic under the rubber pad to increase clearance, but it still would not pass through easily and I saw a potential for a lot of chaffing in the future.

2) There is not enough clearance to fit the harness up through the holder and though the center hole in the "mounting" bracket. Believe me, I tried and tried to no avail. FYI, I used to assemble custom rack mount chassis with nests of wires and they were way easier than trying to complete this install.

In the end, I just ran the harness all the way to the passenger side of the center console. I left enough harness hanging from the under-dash covers to reach the driver's cup holder. I loop it and tuck it under the floor mat. For use, I just pull it out and route it along the center console and up and over to the driver's cup holder where the controller sits in its metal bracket. Not the prettiest set up, but works for when we tow our travel trailer.

Now, I need to figure out how to add a cup holder that I can use when the towing. Any suggestions would be appreciated.