Q5 trailer harness confusion....

[choppstixxx]

I can appreciate that.

What I'm looking for is definitive knowledge of what it does adjust, beyond speculation of what the adjust might do.

I feel that the link in my earlier post (#4) clearly defines what specific areas are adjusted with the OEM setup.

[Norskie]

I'd say if you are towing anything besides maybe a bicycle rack or a hitch basket, I would not want to risk damaging the vehicle by not using the OEM module/wiring/coding. Also the wiring harness that you mention (8R0971541C) is not correct, that looks to be using the Euro pinned connector.

In one of your prior posts you have this: https://www.ecstuning.com/b-genuine-...ss/4l0971124f/

That looks correct, but what's interesting is on that page it shows "Home Page Search SiteSearch 8R0971541C ES#398324" ...

Either way, I need the flat-four connector but an adapter would suffice.

Also came across this:

https://www.audiworld.com/forums/q7-...ulous-2893396/

instead of paying ~$300 for a harness.

I feel that the link in my earlier post (#4) clearly defines what specific areas are adjusted with the OEM setup.

Found it, thanks!

I'm not towing much but do like to have minor projects to work on and keep my eyes open for less expensive parts when they come up.

[choppstixxx]

Either way, I need the flat-four connector but an adapter would suffice.

With my OEM setup I use a Reese 7 way to 4/5 way adapter that works flawlessly. You could always wire up a separate 4 way connection or replace the 7 way with a 4 way, but didn't wanna hack up my OEM wiring.

[Das Ponto]

Just got an oem hitch installed here in canada yesterday.... Flawless install and brake controller put into the cubby left of the steering wheel.

(ball was just put on for measurement hence no locking pin).

Pick up our Basecamp trailer tomorrow.

Sent from my Igloo.

[simy]

I've been doing some research and wanted to make sure I'm getting the right parts. I know the OEM tow hitch package has been discontinued but found this and wanted to make sure this was the right package for my 2017 Q5 3.0T with S-Line package:

https://www.jimellisaudiparts.com/pr...8R0092115.html

And I understand it'd be helpful to get this bracket as well: 8R0907297A

[Brendon11]

This thread seems to be active, so I'll piggy back instead of starting a new one...

I have a curt/ e-trailer.com wiring harness installed in my 2014 TDI Q5. It has the flat 4 connector and has worked perfectly for years while towing my little utility trailer. But now we're looking to get a travel trailer that weights ~3500lbs ... so I have to get the proper wiring and controller installed. I agree with choppstixx and a few others-- when towing some 'real weight', having the proper OEM wiring, control, and coding is worth the peace of mind.

Holy cow, it's confusing. All these parts numbers and no dealer can give definite answers! .

I think I need the following:
Wiring harness-- 8R0971541C
Trailer detection control unit-- 8K0907383E
plastic control unit bracket-- 8R0907297A
7-Pin electrical connector-- 4L0055305U

Is if there is an additional brake control unit? Or is that part of the trailer control unit noted above?

Thank you for your time!

[choppstixxx]

This thread seems to be active, so I'll piggy back instead of starting a new one...

I have a curt/ e-trailer.com wiring harness installed in my 2014 TDI Q5. It has the flat 4 connector and has worked perfectly for years while towing my little utility trailer. But now we're looking to get a travel trailer that weights ~3500lbs ... so I have to get the proper wiring and controller installed. I agree with choppstixx and a few others-- when towing some 'real weight', having the proper OEM wiring, control, and coding is worth the peace of mind.

Holy cow, it's confusing. All these parts numbers and no dealer can give definite answers! .

I think I need the following:
Wiring harness-- 8R0971541C
Trailer detection control unit-- 8K0907383E
plastic control unit bracket-- 8R0907297A
7-Pin electrical connector-- 4L0055305U

Is if there is an additional brake control unit? Or is that part of the trailer control unit noted above?

Thank you for your time!

There is a pretty solid thread detailing exact part #'s etc. on AudiWorld (see post #37).

[Brendon11]

There is a pretty solid thread detailing exact part #'s etc. on AudiWorld (see post #37).

THANK YOU!!!

[choppstixxx]

THANK YOU!!!

Np man, honestly I don’t understand why they stopped making the OEM kit. The vehicle isn’t that old and there obv is a demand for it, I literally bought my kit months before they discontinued it.


Sent from my iPhone using Tapatalk

[simy]

Tow capacity is stated as 4400lbs (USA) but wondering what we can safely push this to. Would it be possible to tow a trailer with a 3500lb car on it?

[choppstixxx]

Tow capacity is stated as 4400lbs (USA) but wondering what we can safely push this to. Would it be possible to tow a trailer with a 3500lb car on it?

I mean a car trailer probably weights at least 1500 lbs? How far is it being driven? I'm sure it could be done, but I would make sure you are using a brake controller and a weight distribution hitch.

[Novarider]

Does the trailer have breaks? If not, Have fun stopping a trailer that weighs more than the tow rating.

[Brendon11]

I found the control module online as an aftermarket replacement by Hella, and it's nearly $100 cheaper than the OEM part 8K0 907 383E. Its the same thing, right??
Has anyone had any experience with this? What (if any) are the downsides of not getting the 'real' OEM part?

[gsulshski]

I found the control module online as an aftermarket replacement by Hella, and it's nearly $100 cheaper than the OEM part 8K0 907 383E. Its the same thing, right??
Has anyone had any experience with this? What (if any) are the downsides of not getting the 'real' OEM part?

Did you ever get the referenced Hella part ? I am looking at installing a stealth hitch with OEM "like" hitch controller and wiring harness. The Hella 5DS010154011 is literally printed on the OEM part 8K0 907 383E and I hooked up a Hella part in my VW Passat and didn't notice anything difference in coding or functionality.


The Hella part is about 1/2 price compared to the OEM part but I don't know if the coding is different or not.

[Brendon11]

Did you ever get the referenced Hella part ? I am looking at installing a stealth hitch with OEM "like" hitch controller and wiring harness. The Hella 5DS010154011 is literally printed on the OEM part 8K0 907 383E and I hooked up a Hella part in my VW Passat and didn't notice anything difference in coding or functionality.


The Hella part is about 1/2 price compared to the OEM part but I don't know if the coding is different or not.

I ordered the Hella part and received an OEM part! haha

[ilq516]

I ordered the Hella part and received an OEM part! haha

Where did you order the hella part from?

[Brendon11]

Where did you order the hella part from?

See post #53 above-- it has the direct link.

[SerJay311]

Anyone have a link to the DIY for the wiring install? lots of videos and instructions on how to install the bumper hardware, but little information on where to plug everything in, wiring and bracket locations. I got lucky and found the OEM hitch (which includes the harness and control modules) through a dealer in Atlanta, bracket was available local.

FYI - i spoke to a few reputable Audi dealers, and the issue is not with the quality of the parts, rather the supply and demand and for some reason the manufacturer ended up discontinuing the part and the dealers having been scrambling to find another source.

[Norskie]

https://www.audiworld.com/forums/q5-...stion-2964381/

[Shaggymatt]

Anyone have a link to the DIY for the wiring install? lots of videos and instructions on how to install the bumper hardware, but little information on where to plug everything in, wiring and bracket locations. I got lucky and found the OEM hitch (which includes the harness and control modules) through a dealer in Atlanta, bracket was available local.

FYI - i spoke to a few reputable Audi dealers, and the issue is not with the quality of the parts, rather the supply and demand and for some reason the manufacturer ended up discontinuing the part and the dealers having been scrambling to find another source.

I've since sold my SQ5, but I installed and coded the OEM hitch in my car. The hitch kit includes everything you need to know, except how to do the long coding.

Be really careful towing anything heavy with the car. Sure it has a 4400# rating, but the SQ5 doesn't have the capability to monitor the transmission temperatures unless you watch through VCDS. I imagine that you can do it on OBDeleven, my only experience is with VCDS as I've been a user for 20+ years.

Your transmission temperature varies a LOT when towing. I bought a pickup just for towing and it's eye opening watching the transmission temperature gauge move around, long hills, driving through towns when you don't have as much airflow over the cooler, etc.

[Norskie]

I've since sold my SQ5, but I installed and coded the OEM hitch in my car. The hitch kit includes everything you need to know, except how to do the long coding.

Be really careful towing anything heavy with the car. Sure it has a 4400# rating, but the SQ5 doesn't have the capability to monitor the transmission temperatures unless you watch through VCDS. I imagine that you can do it on OBDeleven, my only experience is with VCDS as I've been a user for 20+ years.

Your transmission temperature varies a LOT when towing. I bought a pickup just for towing and it's eye opening watching the transmission temperature gauge move around, long hills, driving through towns when you don't have as much airflow over the cooler, etc.

I have watched it with ODBEleven but then again I haven't done anything heavy. I didn't see it go over 63C, then again, I wouldn't know what excessive temps are.

[SerJay311]

I've since sold my SQ5, but I installed and coded the OEM hitch in my car. The hitch kit includes everything you need to know, except how to do the long coding.

Be really careful towing anything heavy with the car. Sure it has a 4400# rating, but the SQ5 doesn't have the capability to monitor the transmission temperatures unless you watch through VCDS. I imagine that you can do it on OBDeleven, my only experience is with VCDS as I've been a user for 20+ years.

Your transmission temperature varies a LOT when towing. I bought a pickup just for towing and it's eye opening watching the transmission temperature gauge move around, long hills, driving through towns when you don't have as much airflow over the cooler, etc.

Fun fact... i thought i found the kit, but they ended up cancelling the order on me as they didn't actually have it and, like every other dealer i've tried, the kits are discontinued. They discontinued them in 2019 with a note that a new kit would replace them... that replacement does not exist yet. So, the search continues.

Looks like eTrailer has an option for the bumper hardware, but the real challenge is finding the wiring harness and console that only came with the kit and never had separate part numbers. eTrailers options for the wiring look like a nightmare.... Any recommendations on wiring alternatives would be greatly appreciated.

PS: I'm only trying to tow a single jetski, so never pushing more than probably 650lbs.

[Shaggymatt]

Looks like eTrailer has an option for the bumper hardware, but the real challenge is finding the wiring harness and console that only came with the kit and never had separate part numbers. eTrailers options for the wiring look like a nightmare.... Any recommendations on wiring alternatives would be greatly appreciated.

PS: I'm only trying to tow a single jetski, so never pushing more than probably 650lbs.

https://www.ebay.com/itm/27436569978...AAAOSwTqBevS34

I towed one of my sailboats with the SQ5, that's about 1100# and I never had any concerns.

[DWAS]

I just installed the Audi OEM trailer hitch and kit on my 2021 SQ5. Went to my local Audi dealer, Audi Central Houston, and they charged me $540 to activate and code the module and re-calibrate the "side Assist".

[scottst]

https://www.ebay.com/itm/27436569978...AAAOSwTqBevS34

I towed one of my sailboats with the SQ5, that's about 1100# and I never had any concerns.

Thanks for the link! From Lithuania. Do we think it is plug and play?


Sent from my iPhone using Tapatalk

[Das Ponto]

Tow capacity is stated as 4400lbs (USA) but wondering what we can safely push this to. Would it be possible to tow a trailer with a 3500lb car on it?

Depends on conditions, and more importantly tongue weight. And as others mentioned, braked vs. non braked trailer makes a huge difference.

We tow our airstream, 2700lb dry weight - probably in around 3000-3200lbs loaded (we avoid loading water until we get to our destination... saves about 280 lbs).

_MG_6768 by Ryan Ponto, on Flickr

[Valpo A7]

Tow capacity is stated as 4400lbs (USA) but wondering what we can safely push this to. Would it be possible to tow a trailer with a 3500lb car on it?

Worst case scenario here. You are towing beyond weight capacity and have a fatal accident. You are criminally negligent.

Can it be done, probably. Should it be done. No.


Sent from my iPhone using Audizine Forum

[Fast4esT]

Need some help here.
My Q already has the bracket installed but I can’t figure out how to get the module installed in the bracket.
Advice? Lol

[Fast4esT]

Need some help here.
My Q already has thmodulee bracket installed but I can’t figure out how to get the installed in the bracket.
Advice? Lol