X5 Hitch & OEM Harness & Coding Installation Retrospective

[TheMane]

Emboldened by posts on this forum, I set about installing a hitch onto my 2014 X5 50i this week and wanted to write up a retrospective with some notes that might be useful for others in the future since I found that a lot of the important information for pulling this off is spread across multiple posts and external resources.

Hitch Install:

I chose the Draw-Tite 75600 since I didn't really care if the hitch was hidden and liked that it would let me keep the factory impact bar. Bonus points that a visible hitch will give my rear bumper some added protection from bump-n-parkers in NYC.

I ordered the hitch from amazon for ~$180 and it came in a few days with some chipped paint from shipping that I spot-painted with rustoleum so it looked uniform.

The installation itself was pretty straightforward. I followed a mix of the video instructions at e-trailer (https://www.etrailer.com/Trailer-Hit...ite/75600.html) and the pdf instructions for stealth hitch (https://cdn.shopify.com/s/files/1/21...f?v=1590006347).

Notes:

• I read a number of reviews on amazon about how the hitch might have shipping damage and considered ordering from somewhere else more expensive but after reading reviews on other sites it seemed like a generally accepted risk for basically any hitch order and really the few damaged areas when it arrived wouldn't have been visible after install, so spot-painting them was just for my own satisfaction / extra rust prevention.
• it was 100% worth it to buy a set of body panel spanning tools for this. I picked up a set from harbor freight for $9 (https://www.harborfreight.com/automo...-pc-64126.html).
• I had read a bunch about the wheel flare rivets being a pain so I bought a set from getbmwparts but it turned out I was able to pry out the existing rivets and just re-use them. If you do want to buy new ones the black rivets are part # 07-14-7-293-278.
• Make sure to wire the electrical harness while the bumper is still off the car, it is MUCH easier than trying to do it after you've put things back together. It's also much easier to run the external wiring after you pull the impact bar off and before you put the hitch on.
• I needed a mount and bracket for the 7 and 4 pole trailer connection that comes with the harness, so bought the HM40978 and the CURT 57204, along with two right-angle brackets from the hardware store to build a mount that fit perfectly. (edited to update, originally said CURT 57202 which turned out to be too long)

Harness Install:

I went with the OEM harness + Control unit. They're part #s 82-71-2-349-500 and 71-60-6-889-589 respectively. Combined these came out to ~$320. There's a lot of mixed opinions out there on using an aftermarket vs OEM harness and I decided to go with OEM because the net cost wasn't that much more than aftermarket and the upside seemed significant (read on for coding impact).

For the install itself I used the stealth hitch instructions (linked above) and the BMW official instructions (https://f15.bimmerpost.com/forums/sh...6&postcount=37). I was very slow and methodical with this.

Notes:

• Running the hitch harness up behind the other harnesses put it in a nice spot for routing wires to the ground/behind the fusebox/etc without creating a mess.
• On my control unit there is a 4th 10-pin port that doesn't seem to appear in the stealth hitch or official BMW documentation. I ultimately left it unoccupied (the 3 occupied ports are all next to each other, the unoccupied 4th port is at the bottom of the unit). I'm still unsure what it's for. EDIT: X-Mon clarified below that this 4th port is for the European electric hitch
• The wire colors in the stealth hitch instructions did not match my OEM harness in one case: specifically the black wire connected to the back of the fuse box was red with a blue stripe on my harness. This is correctly indicated in the BMW instructions.
• In the BMW instructions the RT/GE color indicator means RED/YELLOW (the German word for yellow is gelb).
• After searching around a bit I found the CAN-BUS connector was taped onto the wiring harness exactly as indicated in this doc as X18*1B: https://www.newtis.info/tisv2/a/en/f...-1b/1VnYGe9NiG
• For general electrical safety I disconnected the battery before doing the harness and module install by pulling the negative lead in the trunk after popping the tailgate and then putting the key fob out of sensor range and waiting 15minutes or so for the car to fully power down. Remember not to close the tailgate while the battery is disconnected!!

Coding:

Once the above was all done, I received a hitch electrical warning on my dash. I grabbed a copy of ESYS + psdzData LITE and an ENET cable from amazon.

I found a ton of posts sprinkled throughout the forums about various individual lines to code for the hitch but the approach that looked most promising for 100% replicating what the dealer would do was:

1. add K235 to the HO-WORT folder and write the FA/FP to car
2. VO-Code entire car
3. Inject the CAFD into the AAG unit via:
   Connect => Read FA (VO) => Activate FA (VO) => Read ECU(VCM) => Left-Click on desired ECU => Click on "Detect CAF for SWE" => Select the CAFD matching from latest I-Level Shown => Select OK => Right-Click on ECU (the ECU itself not the underlying CAFD) => Select CODE

Notes:

• I went with K235 for coding since this is the code recommended in the official BMW retrofit instructions linked.
• Despite there being lots of specific per-line coding recommendations in other posts, I VO-Coded the entire car to be safe because I couldn't find a definitive list anywhere of which ECUs would be affected by the K235 addition. Boy did I read a lot about this including all kinds of scary posts about needing a battery charger and bricking the whole car because it might take too long. I did a few test codings and they seemed awfully fast, so I turned off the engine, hooked up ESYS, held my breath, and clicked "code" at the top-level ECU.
• Coding the whole car only took about 3 or 4 minutes and despite some scary cycling of various sytems accompanied by a few scary but brief errors on the idrive screen, once complete I disconnected, turned off the power completely to the car, turned it back on and all was well! Tested all the trailer lights, confirmed the hitch zoom feature was enabled when in reverse, etc. YMMV and maybe there's some huge risk here I'm overlooking so don't take this as gospel (I'm super new to coding) but the whole-car coding approach seemed awfully safe considering how fast it happened. I do know my copy of ESYS has some memory updates I think (memory is set to 4000 in the launcher), maybe that helps it go faster?
• After the coding I dumped all the .ncd files and compared them to what they were beforehand and found that 10 ECUs had changed (11 if you count the AAG control unit itself). I feel like this confirms my suspicion that the OEM harness + module may be worth it over an aftermarket harness since so many other ECUs are impacted by its presence (everything from the parking assist to the chasis management module).

Impacted ECUs:

• KOMBI
• HC2
• ACSM
• DSC2
• HU_NBT
• KAFAS2
• ICM
• ICAM
• BDC_BODY
• PMA2

I also ran a diff on the specific codings that changed if anyone's interested.

Conclusion
Everything is now working wonderfully and I feel very confident in the install. Many thanks to all the people who posted about portions of this process since I relied heavily on other posts along the way. Hope this is helpful to others in the future.

[scotty339]

Good write up. I just put a Curt 13077 on mine which is the same as the DrawTite minus some differences to the bracket to allow the crash bar to re-install. The Curt hitch is much stronger than the OEM crash bar so no worries about leaving it off.

Glad you got it all working. I'll be tackling this project later this year. But for now, all I care about is my bike rack. Haha.

What do you plan on towing?

[TheMane]

Thanks! Yeah the impact bar reinstall hardly seems like a requirement because the hitch crossbars are so much beefier (the drawtite instructions from etrailer actually say to leave it off).

My original goal was also for a bike rack but now that it’s on there with the harness I’ve got family coming after me for all kinds of things (helping my brother in law move some things in a trailer this coming week, towing my dad’s boat). I also want to pick up something like this to expand trunk space for family trips: http://www.walmart.com/ip/MaxxHaul-7...x-20/891865821

Feel free to reach out if you eventually do the harness, this was my first electrical / coding effort with this car and I learned a ton about going from zero to one on the coding front especially.

[RED_Y_]

Great DIY write up! A lot of people had questions about hitch wiring and coding recently.

[skoold2003]

Originally Posted by TheMane

Thanks! Yeah the impact bar reinstall hardly seems like a requirement because the hitch crossbars are so much beefier (the drawtite instructions from etrailer actually say to leave it off).

My original goal was also for a bike rack but now that it’s on there with the harness I’ve got family coming after me for all kinds of things (helping my brother in law move some things in a trailer this coming week, towing my dad’s boat). I also want to pick up something like this to expand trunk space for family trips: http://www.walmart.com/ip/MaxxHaul-7...x-20/891865821

Feel free to reach out if you eventually do the harness, this was my first electrical / coding effort with this car and I learned a ton about going from zero to one on the coding front especially.

I think the coding aspect changes depending on whether you have the trailer preparation option with your car. I remember only having to fdl code a couple of things.

[X Mon™]

FWIW, the 4th port in the AAG is for the automated/power trailer hitch option available in Europe.

[TheMane]

Originally Posted by X Mon™

FWIW, the 4th port in the AAG is for the automated/power trailer hitch option available in Europe.

AHA! That makes sense.

[Kendal]

Thanks for the great write up. I just ordered a Curt hitch and didn't know which route to go on the wiring. I am now going to get the OEM wiring harness. I haven't done any coding but I am going to give it a shot.

[TheMane]

Originally Posted by skoold2003

I think the coding aspect changes depending on whether you have the trailer preparation option with your car. I remember only having to fdl code a couple of things.

Yeah could be. My car has the "S8SL - Trailer coupling preparation" option on it if that helps for comparison, but for the life of me I can't figure out what that option actually means since it didn't seem to make anything different during the install.

Maybe it means the bumper was pre-trimmed since I didn't have to do any fascia cutting?

[328<335]

Originally Posted by TheMane

Coding:

Once the above was all done, I received a hitch electrical warning on my dash. I grabbed a copy of ESYS + psdzData LITE and an ENET cable from amazon.

I found a ton of posts sprinkled throughout the forums about various individual lines to code for the hitch but the approach that looked most promising for 100% replicating what the dealer would do was:

1. add K235 to the HO-WORT folder and write the FA/FP to car
2. VO-Code entire car
3. Inject the CAFD into the AAG unit via:
   Connect => Read FA (VO) => Activate FA (VO) => Read ECU(VCM) => Left-Click on desired ECU => Click on "Detect CAF for SWE" => Select the CAFD matching from latest I-Level Shown => Select OK => Right-Click on ECU (the ECU itself not the underlying CAFD) => Select CODE

.

Hey TheMane - hoping you can help. I'm trying to code the same and followed your directions, however, it seems that my zoom does not appear and when I plug in the trailer light tester(to trick the car into thinking a trailer is connected) the rear PDC remains active. I think I may have coded incorrectly. The only thing that I can see being off is the latest CAFD from the latest pszdata that I have is newer than my I-level. Would that be a problem? Any help would be appreciated! Thanks

[TheMane]

Originally Posted by 328<335

Hey TheMane - hoping you can help. I'm trying to code the same and followed your directions, however, it seems that my zoom does not appear and when I plug in the trailer light tester(to trick the car into thinking a trailer is connected) the rear PDC remains active. I think I may have coded incorrectly. The only thing that I can see being off is the latest CAFD from the latest pszdata that I have is newer than my I-level. Would that be a problem? Any help would be appreciated! Thanks

Hey sorry I’ve been away from the forum for the past week or so. Afraid I’m no coding expert so I’m not sure how to diagnose the issue.

All I can guess to check is whether the hitch icon appears when you’re in parking mode at all? It should always show up on the bottom of the stacked items to the left of the camera view even if nothing is connected to the electrical port (so you can manually select it for a hitch view even if you’re not using a powered trailer).

If not it sounds like maybe the coding didn’t take or wasn’t executed correctly.

You might also ask in the bigger coding megathread where some of the experts hang out. I believe there are some other documented approaches to hitch coding in that thread as well.

Best of luck!

[328<335]

Originally Posted by TheMane

Hey sorry I’ve been away from the forum for the past week or so. Afraid I’m no coding expert so I’m not sure how to diagnose the issue.

All I can guess to check is whether the hitch icon appears when you’re in parking mode at all? It should always show up on the bottom of the stacked items to the left of the camera view even if nothing is connected to the electrical port (so you can manually select it for a hitch view even if you’re not using a powered trailer).

If not it sounds like maybe the coding didn’t take or wasn’t executed correctly.

You might also ask in the bigger coding megathread where some of the experts hang out. I believe there are some other documented approaches to hitch coding in that thread as well.

Best of luck!

No worries! Thanks for the info. I bought a new tester and turns out all but the zoom feature was coded. I manually coded the zoom, so all is good now. Thanks again!

[Kendal]

I recently installed a curt hitch with the OEM wiring harness and control module. I found that the control module that you have listed is no longer being made and has been replace with part#63-11-9-463-372.

Also I am having trouble finding the R2*1B 24 pin socket casing that wires A7 and A8 plug into. Can you help in poiting me to where it is?

[TheMane]

Originally Posted by Kendal

I recently installed a curt hitch with the OEM wiring harness and control module. I found that the control module that you have listed is no longer being made and has been replace with part#63-11-9-463-372.

Also I am having trouble finding the R2*1B 24 pin socket casing that wires A7 and A8 plug into. Can you help in poiting me to where it is?

It's behind the fuse panel. The stealth hitch instructions show the location well starting on step 32: https://cdn.shopify.com/s/files/1/21...f?v=1590006347

[Kendal]

Thanks, I finally found it and got it all wired up and coded. It works great! Thanks for all the information. I couldn't have done it without it.

[steveg_nh]

Originally Posted by Kendal

Thanks, I finally found it and got it all wired up and coded. It works great! Thanks for all the information. I couldn't have done it without it.

Agreed, excellent assistance, and saved me from posting a thread about wiring the OEM harness. Looking at the BMW instructions, I could not figure out that the plugs I was to insert some of the terminals into was the back side of the fuse panel. Makes total sense now!

One question though - should you disconnect the battery before doing any of these changes with the OEM harness? If you do disconnect the battery (this is my first newer BMW) when I reconnect will anything not work? Radio/security codes I should locate first, or stuff like that?

Thank you

[X Mon™]

Originally Posted by steveg_nh

Agreed, excellent assistance, and saved me from posting a thread about wiring the OEM harness. Looking at the BMW instructions, I could not figure out that the plugs I was to insert some of the terminals into was the back side of the fuse panel. Makes total sense now!

One question though - should you disconnect the battery before doing any of these changes with the OEM harness? If you do disconnect the battery (this is my first newer BMW) when I reconnect will anything not work? Radio/security codes I should locate first, or stuff like that?

Thank you

Yes, it's prudent to pull the negative lead off the battery. There were no issues regarding lock out codes from the battery pull.

I can't remember if it was from adding the camera or the hitch, but one of the connector housings was missing. It can be sourced from the dealer if you end up down that road.

[steveg_nh]

Originally Posted by X Mon™

Yes, it's prudent to pull the negative lead off the battery. There were no issues regarding lock out codes from the battery pull.

I can't remember if it was from adding the camera or the hitch, but one of the connector housings was missing. It can be sourced from the dealer if you end up down that road.

Thanks. So just like an old school car, just disconnect, do your work, reconnect and all should be good?

As far as missing connector housings, as far as I can tell, I have everything I need. I found the Can bus 3 wire connector, and the rest of the wires are to the fuse panel, and the connector behind it.

[TheMane]

I updated the harness notes in the main post to reflect this but yes I disconnected the battery before doing the harness install— you’re poking around the fusebox, inserting wires, and disconnecting/reconnecting grounds. The last thing you want is to short something in the process while it’s energized.

[steveg_nh]

Thanks. I did the wiring this morning, with the exception of plugging in the 3 wire CANbus connector, and the trailer module 3 connectors (module is arriving later today). Went super smooth once I saw what was in there. Pretty easy actually, just nerve racking digging into wiring in your new-to-you, and still under warranty, X5.

Thanks for this post, it was fantastic to help with the project.

[ohmyecu]

i guess you're lucky... i cant inject cafd in mine...
started a thread here https://f15.bimmerpost.com/forums/sh....php?t=1760775

[kasb58]

Hello, I have a 2016 F15. Has anyone been able to test the OEM wiring harness and plug successfully with a seven ping or four pin tester? I had the harness installed and coded by an independent shop but when I attach either tester, I see flashing LT, RT and RL. When probing with a meter, I see fluctuating voltage on the four pin. The seven pin tester does show 12v but again the RT, LT and RL are barely flashing more like a flicker. I am wondering if I need a trailer to properly test. Any suggestions? Thanks