Towing Setup Questions
 

I just picked up a 2011 X5 35D tonight. I want to set up a tow hitch on it for taking my race car to the track. I have do e tons of reading so far on it and still have some questions. I plan on ordering this oem kit with wiring...

https://www.ecstuning.com/b-genuine-...t/71602156525/

how straight forward is the wiring portion of it? Do all these cars need to be coded after the instal? What other kits have everyone used?

I have installed the OEM kit on my E53 couple weeks ago. Wiring harness was plug and play, and no coding was required.
Your kit however according to the install manual attached on ecstuning link you provided requires coding after install. Wiring harness install is also well described and seem pretty straightforward.

I think BMWofsouthatlanat has it with free shipping, $439 or so (I think)

Install is pretty straighforward - harness is plug and play. You do need to have it coded for all features to work, but my recollection is that it will be NOT be fully functional without coding.

Oh, near unanimous agreement that the BMW harness is the one you should use- hitch itself there are multiple vendors, but the harness should be BMW (with oe connectors, etc)

GL

Wow....didn't have to code anything? You are lucky cuz my trailer brake lights don't work and I get an error saying a trailer bulb is out . Still trying to figure it out, even after I added the brake module to the Vehicle Order. Signal lights work but nothing on brakes.....




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According to BMW "The vehicle must be reprogrammed before the trailer lights will work properly". Most report brake lights not working before getting programming done.

Just a reminder for those reading this and may get confused by some of the replies...

...the E53 and E70 X5s have totally different communication bus systems. The e53 is now an old generation BMW...it uses a much simpler and less complex communication bus. Depending on if you have the low cluster (KOMBI - K bus) or the high cluster (I, K, M, P, CAN, Diangositc busses)...it is still much less complex. The the e70 X5 with its new generation communication busses like the LIN, MOST, Byteflite busses...is much more complex...and even something as simple as installing a trailer hitch may require coding so that (as mentioned) back up lights and even reverse camera come on line to aid/assist:

You have to have it coded otherwise the brake lights won't work through the harness.

Great. After some more research I think I am going to go with the OEM harness but Reese hitch as it wont require as much cutting. My local BMW dealer will do just the coding for $145. Not terrible.

I also red a few places that it is not necessary to use the load distribution hitch i have set up for the trailer on this X5. Is that true? Any reason not to use it?

BMW states it SHOULD NOT be used- not 'that it isnt necessary'. Very different issues.

Can someone explain why it should not be used?

I am assuming you made all the necessary calculations to go with aftermarket hitch. Personally these top 3 items helped me decide between OEM v aftermarket:

1- Safety: Many aftermarket products sacrifice OEM safety features in terms of impact or high load absorbance

2- Fitment: Surely did not want to be a statistics with messed up bumper stories

3- Max weight specs: If the hitch is below OEM specs (GW, tongue, etc..)

BMW will be best positioned to explain. I am no expert and my limited knowledge tells me weight distribution could abuse your transmission because it is designed to shift weight between front and rear axles.

Fyi The wiring instructions from the hidden hitch website are the most detailed I could find when I installed my oem harness.

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The wiring instructions are simple enough to understand, and you can install the hitch yourself if you are the slightest bit mechanically inclined. The hardest part will be trimming the rear bumper for the OE hitch.

There are some people towing with WD hitches, this is not recommended with the OE hitch. See this thread for details http://www.bimmerfest.com/forums/sho...d.php?t=852873

I have PDC and comfort access. W the OEM kit I did not have to touch thw external wiring for either. The trailer harness comes with wires and plug for CA that are superfluous on a 2011. Just install the trailer harness thru the second unused body pass thru. I did not have to move the PDC plug either. The only existing wiring I touched was
(1) relocate part of the PDC harness attached to the bumper cover to make space for the cut out
(2) splice into the backup light wire (P side), if your trailer has backup lights (mine does).

The cutout on the bumper can be very minimal, in which case you won't need the additional trim piece. As others suggest, if you angle the 7-pin receptive downward,it reduces the needed bumper cutout significantly.

Finally, I highly recommend the prodigy wireless ebrake controller. Much easier and more convenient than hacking your cup holder for the hard wired controller.

John

The OEM hitch lacks a longitudinal member to resist the torque a WD hitch places on the receiver. I looked at how a trailer shop in Canada adds a reinforcement and I agree with BMW's recommendation that WD is to be avoided unless you strengthen the receiver attachment, and add a fore/aft reinforcement bar to resist twist. Unless you don't tow often and you are using light duty WD bars I would avoid WD.

I just sold my high end enclosed trailer because it needed WD (tongue weight near 1300lbs when loaded up), and bought a bare bones all aluminum ATC 20' to keep weight low enough to avoid the need for WD (tongue weight about 200lbs empty).