Q5 trailer harness confusion....

[MadMen]

Been doing some research to prepare for installing a hitch on my '16 Q5. The hitch itself seems easy enough, but lots of confusion about the wiring harness.

I first found this video showing the install on my exact same Q5 (even the same color).

https://youtu.be/7HIjFx3TmqU

While a bit involved, it's certainly doable. But then I read through the forums and folks keep mentioning the need for programming the harness with VCDS. They didn't do that in the video, nor did they even mention it. They tested it and it seemed to work.

So what am I missing here?

[choppstixxx]

Been doing some research to prepare for installing a hitch on my '16 Q5. The hitch itself seems easy enough, but lots of confusion about the wiring harness.

I first found this video showing the install on my exact same Q5 (even the same color).

https://youtu.be/7HIjFx3TmqU

While a bit involved, it's certainly doable. But then I read through the forums and folks keep mentioning the need for programming the harness with VCDS. They didn't do that in the video, nor did they even mention it. They tested it and it seemed to work.

So what am I missing here?

In that video they are using a non-OEM harness, I don't recommend that route if your towing anything that weights a good amount. IMO the added cost for the OEM hitch/harness is worth it for peace of mind and to have something that is tied in perfectly/meant to be there.
The OEM harness uses a module that controls all engine/lighting & parking sensor changes and uses a 7 pin round plug. I think those aftermarket harnesses just patch into the OEM tail lights to make sure the trailer "works" when plugged in. However I'm sure your dash will have plenty of errors/warnings because of it.

[Shaggymatt]

I installed the OEM hitch, which I believe is no longer produced. The actual installation was pretty easy, they did tell you to remove the rear seat or something like that, but it wasn't necessary.

Most of my the time was spent messing with the coding. It's been a while, but IIRC, it's all done in long coding.

[choppstixxx]

Most of my the time was spent messing with the coding. It's been a while, but IIRC, it's all done in long coding.

I'll do ya one better, here's my thread with detailed coding instructions:
Clicky Click

[Shaggymatt]

I'll do ya one better, here's my thread with detailed coding instructions:
Clicky Click

If only I had that years ago when I did mine.

Have you towed your Sea Ray with the Q? I bought a 190 BR a few months ago. Was downright scary towing with the SQ, but later learned there was an issue with the trailer brake on one wheel. While getting that resolved, I ended up buying a pickup just for towing.

Curious how your heavier towing experience has been. I'm quite happy to not tow heavy with the Audi. Towing my sailboats is cake but they're around 1300#.

[choppstixxx]

If only I had that years ago when I did mine.

Have you towed your Sea Ray with the Q? I bought a 190 BR a few months ago. Was downright scary towing with the SQ, but later learned there was an issue with the trailer brake on one wheel. While getting that resolved, I ended up buying a pickup just for towing.

Curious how your heavier towing experience has been. I'm quite happy to not tow heavy with the Audi. Towing my sailboats is cake but they're around 1300#.

Works perfectly fine, every year I tow my 18ft Searay from the winter storage to home which is about 45 mins away. Then from home to our slip which is about 1.5 hrs away and is mostly highway. Also took it down to a rental lake house which is about 30 mins away with no issues at all. Boat/trailer weights around 3000 lbs total, I use a Curt hitch w/a 2" drop that I flipped the ball to create a 2" rise. Makes the trailer nice and level and very stable.

[MadMen]

If only I had that years ago when I did mine.

Have you towed your Sea Ray with the Q? I bought a 190 BR a few months ago. Was downright scary towing with the SQ, but later learned there was an issue with the trailer brake on one wheel. While getting that resolved, I ended up buying a pickup just for towing.

Curious how your heavier towing experience has been. I'm quite happy to not tow heavy with the Audi. Towing my sailboats is cake but they're around 1300#.

Thanks for the info. I'm going to get an estimate from the dealer to see what it would be for them to just do it all.

But funny thing is, it's to tow a boat - most likely a Sea Ray 20'. But I would just be towing a few miles from the storage facility to the ramp. Shouldn't have to be on the highway with it at all.

[Shaggymatt]

I literally thought we were going to wreck driving the boat home when I bought it. Went over an expansion joint on a bridge doing 65. Started the fishtailing, gave it a touch of gas as you're supposed to do and it got worse. Eventually, it settled down. Every 18 wheeler that passed was downright scary. Later to find out, I was lucky that it didn't catch on fire because of the braking system on the trailer. The previous owner cut the brakes and they didn't retract the drums. All four-wheel hubs needed to be replaced, brakes lines and the coupler. $2500 later, my turn-key boat is just about that.

But that's pretty funny that we hit an 18', 19' and 20' in this thread.

[MadMen]

I installed the OEM hitch, which I believe is no longer produced. The actual installation was pretty easy, they did tell you to remove the rear seat or something like that, but it wasn't necessary.

Most of my the time was spent messing with the coding. It's been a while, but IIRC, it's all done in long coding.

Ok - Dealer confirmed OEM hitch is no longer available. So how do I get the OEM wiring harness? Is there an equivalent aftermarket harness if the E-trailer harness is not recommended?

Thanks!

[choppstixxx]

Ok - Dealer confirmed OEM hitch is no longer available. So how do I get the OEM wiring harness? Is there an equivalent aftermarket harness if the E-trailer harness is not recommended?

Thanks!

You can find some non-local dealers that still have the OEM hitch/module/harness kit for sale via eBay or just a simple Google search for part #8R0-092-115

[MadMen]

You can find some non-local dealers that still have the OEM hitch/module/harness kit for sale via eBay or just a simple Google search for part #8R0-092-115

Thanks again! Yowza! $825!! Any chance the wiring harness can be had separately, since the hitch itself looks identical to the $200 Draw-tite hitch?

[choppstixxx]

Thanks again! Yowza! $825!! Any chance the wiring harness can be had separately, since the hitch itself looks identical to the $200 Draw-tite hitch?

Probably not since the kit is now discontinued, your best bet is to find the entire thing and buy it ASAP. It's going to get harder and harder to find the OEM kit as time goes on unless you find like a wrecked Q5/SQ5 with the hitch installed. A few months ago I bought mine for just under $500 shipped from an Audi dealer in FL, glad I did.

[MadMen]

Probably not since the kit is now discontinued, your best bet is to find the entire thing and buy it ASAP. It's going to get harder and harder to find the OEM kit as time goes on unless you find like a wrecked Q5/SQ5 with the hitch installed. A few months ago I bought mine for just under $500 shipped from an Audi dealer in FL, glad I did.

Ok - I found it at a local dealer for $668 for everything, including the module bracket. Made the purchase. I'll assume I can code using my OBDeleven instead of VCDS hopefully.

Thanks guys!!

[MadMen]

Well crap. Dealer cancelled my order. Said they can no longer get them :/

Looks like I'll take my chances with the etrailer stuff. I won't be pulling it far - and rarely if ever on a highway.

[choppstixxx]

Well crap. Dealer cancelled my order. Said they can no longer get them :/

Looks like I'll take my chances with the etrailer stuff. I won't be pulling it far - and rarely if ever on a highway.

If your pulling a boat with it regardless of distance/speed I would strongly recommend going the OEM route at all possible costs. The OEM trailer module also adjusts the engine/braking/cooling functions, where as the aftermarket E-Trailer wiring will not.

[Novarider]

Why did they stop making the hitch for the Q5? It's not like they stopped making Q5's

[MadMen]

If your pulling a boat with it regardless of distance/speed I would strongly recommend going the OEM route at all possible costs. The OEM trailer module also adjusts the engine/braking/cooling functions, where as the aftermarket E-Trailer wiring will not.

The only OEM I can find has a 1-2 month ship date. And I bet that would get cancelled too, since they would be ordering it :/.

My storage spot is literally across the street from the ramp. I probably don't even need trailer lights - except for getting the boat from the dealer across town....

[choppstixxx]

Why did they stop making the hitch for the Q5? It's not like they stopped making Q5's

The last year they made the prior gen Q5/SQ5 was 2017, but I too agree IDK why they are discontinuing the hitch kit part #. Glad I bought mine when I did.

The only OEM I can find has a 1-2 month ship date. And I bet that would get cancelled too, since they would be ordering it :/.

My storage spot is literally across the street from the ramp. I probably don't even need trailer lights - except for getting the boat from the dealer across town....

Trust me I know what you mean as I have a dry slip in the parking lot of my launch. I am just saying that pulling a 3000ish lb boat out of the water adds a good amount of stress on the engine/brakes/cooling system. I rather utilize the OEM module/system that will safely allow me to do so.

Here's a link to the OEM module, looks like you can still buy it. Not sure about what the part # is of the wiring harness tho.

[Shaggymatt]

Transmission was my biggest concern towing with the SQ5. The Titan I got, the temp gauge goes up 3/4 of the way on some of the larger hills here in PA when I'm pulling, I believe that has two transmission coolers. Think the tow weight is somewhere just over 3500# if I had to guess, given a dry weight on boat of 2750#. If you're towing in hilly areas at higher weights I'd definitely only do so with OEM wiring.

[MadMen]

The last year they made the prior gen Q5/SQ5 was 2017, but I too agree IDK why they are discontinuing the hitch kit part #. Glad I bought mine when I did.


Trust me I know what you mean as I have a dry slip in the parking lot of my launch. I am just saying that pulling a 3000ish lb boat out of the water adds a good amount of stress on the engine/brakes/cooling system. I rather utilize the OEM module/system that will safely allow me to do so.

Here's a link to the OEM module, looks like you can still buy it. Not sure about what the part # is of the wiring harness tho.

Yep - seems you can still get the controller, but the harness is the part that I can't find. I think it may only come with the hitch as a kit.

[choppstixxx]

Yep - seems you can still get the controller, but the harness is the part that I can't find. I think it may only come with the hitch as a kit.

Tonight I'll see if I can get a part # off my wiring harness to see if it can be ordered for you.

[MadMen]

Tonight I'll see if I can get a part # off my wiring harness to see if it can be ordered for you.

Thank you! Really appreciate the help.

[choppstixxx]

Thank you! Really appreciate the help.

I actually think this is the harness, part #4L0971124F. It says it's for the Q7, but all the connectors etc. look like the one that came with my Q5 kit. Obviously I will confirm the part # tonight tho.

[choppstixxx]

So I checked my OEM harness and it's actually a Westfalia part, so it doesn't have an Audi part #. I tried to find some other part #, but all I could find was the barcode #305214321003.

[MadMen]

So I checked my OEM harness and it's actually a Westfalia part, so it doesn't have an Audi part #. I tried to find some other part #, but all I could find was the barcode #305214321003.

Thanks for trying. I couldn't find anything either. Ended up just using the non-splice Tekonsha wiring kit from etrailer. Other than the annoyance of having to run it through the hatch when needed, it works great - with no cutting or splicing into the factory wires at all.

The Q5 tows the 3k lb boat and trailer with ease. Barely breaks a sweat. I just tow in sport mode to keep the revs a bit more in the power range.

[dubjager]

So I've been waiting and waiting and finally ready to buy this hitch for my SQ5 and it is discontinued.
Anyone know why? Parts adviser I spoke to said there must be something wrong with it for them to clear inventory the way they have.

So, I am in a bit of pickle. I'd like to keep it all OEM, fit and finish is really important to me.
Going to keep an eye on dismantlers to see if one pops up.
But anyway of doing a clean/OE install with one of the aftermarket hitch companies?

[choppstixxx]

But anyway of doing a clean/OE install with one of the aftermarket hitch companies?

If you want OEM look/fit use the Draw-Tite or if you want a sleeker/hidden one use Stealth or Invisi Hitch.
Then for wiring you can sort of cobble together some of the OEM parts with what we discussed already above.

[dubjager]

That's great to hear.
So to summarize I would be able to use the following and get a pretty decent OE fit?
#4L0971124F
8R0-907-297-A

Thanks for your help.
Also do you have 8R0807819M1RR but with the OE cutout for the hitch? Or did you cut yours out yourself?

[choppstixxx]

That's great to hear.
So to summarize I would be able to use the following and get a pretty decent OE fit?
#4L0971124F
8R0-907-297-A

Thanks for your help.
Also do you have 8R0807819M1RR but with the OE cutout for the hitch? Or did you cut yours out yourself?

Module: 8K0907383E
Wiring Harness: 4L0971124F (meant for the Q7, so IDK if it's pinned 100% correctly)
For the valence cutout, I actually bought this pre-done one from Audi that is for I believe the prev. gen Q5 but fits/matches perfectly.

[dubjager]

really appreciate all the help with the part numbers!
Crazy to see how all the wiring and modules add up- but the added utility of the hitch is great.

[seanf86]

really appreciate all the help with the part numbers!
Crazy to see how all the wiring and modules add up- but the added utility of the hitch is great.

if you need the trailer module bracket 8R0-907-297-A I've got one for sale as mine had the bracket already installed when I put my factory hitch on.

[choppstixxx]

if you need the trailer module bracket 8R0-907-297-A I've got one for sale as mine had the bracket already installed when I put my factory hitch on.

Def. recommend purchasing this if you don't have it, I thought I would just tuck my module somewhere but the bracket keeps it away from the OEM wiring mess and out of harms way.

[dubjager]

if you need the trailer module bracket 8R0-907-297-A I've got one for sale as mine had the bracket already installed when I put my factory hitch on.

Thank you- how much are you looking to let it go for?

I am going to just piece it together, looking for a hitch for either a Q5 or Macan, looks like they are the exact same piece. Ironically, Porsche folks have been skipping the Porsche tax and buying the Audi part...

[seanf86]

Thank you- how much are you looking to let it go for?

I am going to just piece it together, looking for a hitch for either a Q5 or Macan, looks like they are the exact same piece. Ironically, Porsche folks have been skipping the Porsche tax and buying the Audi part...

$50usd shipped

Let me know

Sent from my LM-G710 using Tapatalk

[yup]

ECS shows the Q5 wiring harness as: 8R0971541C

and the control module as: 8K0907383D

These are for the 3.0T models

[Norskie]

So let's see if I have this summarized correctly:

1. Control module 8K0907383D ~$200
2. Wiring harness 8R0971541C ~$200
3. Module brackets 8R0907297A ~$60
4. Coding to make it all work

Vs. a $75 generic tow module controller spliced into the wiring.

The main benefit of the modules and harness etc is for the various ECU's to modify traction/stability control, shift points and something to do with cooling? And it's only really needed when towing closer to the tow limit?

I'm leaning towards assuming that for us towing < 2000# the OEM modules and harnesses might be overkill / over-engineering.

[choppstixxx]

So let's see if I have this summarized correctly:

1. Control module 8K0907383D ~$200
2. Wiring harness 8R0971541C ~$200
3. Module brackets 8R0907297A ~$60
4. Coding to make it all work

Vs. a $75 generic tow module controller spliced into the wiring.

The main benefit of the modules and harness etc is for the various ECU's to modify traction/stability control, shift points and something to do with cooling? And it's only really needed when towing closer to the tow limit?

I'm leaning towards assuming that for us towing < 2000# the OEM modules and harnesses might be overkill / over-engineering.

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.

[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.

How would it be damaged?

[choppstixxx]

How would it be damaged?

Pulling anything heavy for an extended period of time (let's just put out a hypothetical # of 1k lbs) puts added stress to the entire car. Again that is why there is a OEM module that adjusts everything, like the ABS system/cooling/shift points etc. In the end this is your vehicle so do whatever works for you, but for me having the peace of mind that I have an OEM setup on a vehicle that cost upwards of $50k when new was the only option.

[Norskie]

Pulling anything heavy for an extended period of time (let's just put out a hypothetical # of 1k lbs) puts added stress to the entire car. Again that is why there is a OEM module that adjusts everything, like the ABS system/cooling/shift points etc. In the end this is your vehicle so do whatever works for you, but for me having the peace of mind that I have an OEM setup on a vehicle that cost upwards of $50k when new was the only option.

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.