[suiteskull]

I did a search and was not sure if this has been covered before and was not very sure what keywords to search for, so pardon me if this was covered already!

The reason for the question: I have towed with my T1 V8 that has a simple piggyback trailer light system and was not impressed with the transmissions ability to downshift, to keep highway speeds, on its own. Sport mode was a bit better but still not great.

To those of you with OEM VW Tow modules (or knowledge of):
1. My understanding is that the shift strategies are changed when it senses a trailer is connected. Can anyone quantify what changes are made? Ie. is it basically like manually shifting into sport mode and nothing more, or does it do anything above and beyond?
2. Assuming the shift strategy is worth the effort, is there a way to install a "switch" or fool the ECU/TCU into thinking it is in tow mode? I imagine this is not as simple as a switch, but I wonder what the logic is to let the system know it is towing.

I have access to VCDS and assume that I could purchase a 7L0.907.383 or kit and program it for full functionality, but would rather save the money if it is not worth it.

 

[EddieB]

I did a search and was not sure if this has been covered before and was not very sure what keywords to search for, so pardon me if this was covered already!

The reason for the question: I have towed with my T1 V8 that has a simple piggyback trailer light system and was not impressed with the transmissions ability to downshift, to keep highway speeds, on its own. Sport mode was a bit better but still not great.

To those of you with OEM VW Tow modules (or knowledge of):
1. My understanding is that the shift strategies are changed when it senses a trailer is connected. Can anyone quantify what changes are made? Ie. is it basically like manually shifting into sport mode and nothing more, or does it do anything above and beyond?
2. Assuming the shift strategy is worth the effort, is there a way to install a "switch" or fool the ECU/TCU into thinking it is in tow mode? I imagine this is not as simple as a switch, but I wonder what the logic is to let the system know it is towing.

I have access to VCDS and assume that I could purchase a 7L0.907.383 or kit and program it for full functionality, but would rather save the money if it is not worth it.

My T3 2016 V6 with a factory installed hitch definitely changes when trailer connected. It has a icon showing car with trailer. I could not find any prewiring for brake controller, so I had to add. What is surprising is the shifting seems smoother when in Cruise, especially on Interstate highways. I asked the VW Service Manager (he drives a 2006 V10 TDI), if I should shift manually, and he said NO. Let the computer make the changes. The only time I shift manually is on very steep (7%+) uphill grades. That allows me to maintain at least 45 MPH. Should I be concerned with high rev's going up steep grades? - he said no. Occasionally will rev up to 5K when starting uphill. My temp is always dead on 200 degrees. Does not change, even in 95 degrees heat in eastern Montana. I am most impressed with the brakes. I know that if my trailer brakes fail, this vehicle will stop.

I have more frequent oil changes than standard, and inspect the hitch for any damage (I also use a very expensive hitch system - ProPride 3. Zero sway and tracks nicely behind the vehicle. I am hoping to get more than 150K out of this tow vehicle. I am at 60K now.

 

[suiteskull]

My T3 2016 V6 with a factory installed hitch definitely changes when trailer connected. It has a icon showing car with trailer. I could not find any prewiring for brake controller, so I had to add. What is surprising is the shifting seems smoother when in Cruise, especially on Interstate highways. I asked the VW Service Manager (he drives a 2006 V10 TDI), if I should shift manually, and he said NO. Let the computer make the changes. The only time I shift manually is on very steep (7%+) uphill grades. That allows me to maintain at least 45 MPH. Should I be concerned with high rev's going up steep grades? - he said no. Occasionally will rev up to 5K when starting uphill. My temp is always dead on 200 degrees. Does not change, even in 95 degrees heat in eastern Montana. I am most impressed with the brakes. I know that if my trailer brakes fail, this vehicle will stop.

I have more frequent oil changes than standard, and inspect the hitch for any damage (I also use a very expensive hitch system - ProPride 3. Zero sway and tracks nicely behind the vehicle. I am hoping to get more than 150K out of this tow vehicle. I am at 60K now.

That is kind of what I would like to emulate with my older Touareg. I have a feeling there may be some more bells and whistles associated with the T3 platform over the T1. I am deciding what brake controller I would like to add to the vehicle at this point, but that is another thread entirely...

 

[mhucuoly]

I have a question hopefully someone knows.

I know that for the Range Rover you can buy as an option the tow module. When a trailer is plugged in it shuts of the rear parking sensor and disables the ride height.

Now the technical question, Does it change how the transmission operates?

I have an 04 RR that someone installed a tow module but it does not look like that RR specific one. So it does not shut the parking sensor off or lock the road height. I could care less about this feature. What does concern me is how the transmission operates. Towing a heavy load in overdrive is usually a quick way to burn a transmission out. I tow a boat and sometimes it seems to hunt for the gear.

Anyone know?

 

[Black Grouse]

I have a question hopefully someone knows.

I know that for the Range Rover you can buy as an option the tow module. When a trailer is plugged in it shuts of the rear parking sensor and disables the ride height.

Now the technical question, Does it change how the transmission operates?

I have an 04 RR that someone installed a tow module but it does not look like that RR specific one. So it does not shut the parking sensor off or lock the road height. I could care less about this feature. What does concern me is how the transmission operates. Towing a heavy load in overdrive is usually a quick way to burn a transmission out. I tow a boat and sometimes it seems to hunt for the gear.

Anyone know?

The knowledge of Range Rovers on this VW Touareg forum is minimal - the best advice is to avoid them like the plague as they're the most unreliable brand in the world. They're built just down the road from where I live, they aren't something we're proud of.

 

[ideaHex]

I have a 2008 TDI V6. I have a swing out tyre carrier that fits in tow hitch that has a tail light. I have it connected to the trailer lights and this required the addition of resistors to fool the vehicle into thinking it had a trailer connected. Otherwise the taillight would not light. The good thing is it also stopped the rear sensors. I haven't noticed any change in shifting. I thought I may have read somewhere that it affects the ABS.

I would also be interested if anyone has more information about this.

 

[suiteskull]

I have a 2008 TDI V6. I have a swing out tyre carrier that fits in tow hitch that has a tail light. I have it connected to the trailer lights and this required the addition of resistors to fool the vehicle into thinking it had a trailer connected. Otherwise the taillight would not light. The good thing is it also stopped the rear sensors. I haven't noticed any change in shifting. I thought I may have read somewhere that it affects the ABS.

I would also be interested if anyone has more information about this.

Is your trailer wiring setup factory? It sounds like it, but I wanted to be certain for clarity.

 

[ideaHex]

Is your trailer wiring setup factory? It sounds like it, but I wanted to be certain for clarity.

I believe so. The vehicle recognizes when a trailer has a light out.

 

[volkswagens-for-life]

I did a search and was not sure if this has been covered before and was not very sure what keywords to search for, so pardon me if this was covered already!

The reason for the question: I have towed with my T1 V8 that has a simple piggyback trailer light system and was not impressed with the transmissions ability to downshift, to keep highway speeds, on its own. Sport mode was a bit better but still not great.

To those of you with OEM VW Tow modules (or knowledge of):
1. My understanding is that the shift strategies are changed when it senses a trailer is connected. Can anyone quantify what changes are made? Ie. is it basically like manually shifting into sport mode and nothing more, or does it do anything above and beyond?
2. Assuming the shift strategy is worth the effort, is there a way to install a "switch" or fool the ECU/TCU into thinking it is in tow mode? I imagine this is not as simple as a switch, but I wonder what the logic is to let the system know it is towing.

I have access to VCDS and assume that I could purchase a 7L0.907.383 or kit and program it for full functionality, but would rather save the money if it is not worth it.

huge differences with the tow module. It simply detects when something is plugged into the wiring harness. It changes a lot more than just shifting.

That is kind of what I would like to emulate with my older Touareg. I have a feeling there may be some more bells and whistles associated with the T3 platform over the T1. I am deciding what brake controller I would like to add to the vehicle at this point, but that is another thread entirely...

no comparison

 

[suiteskull]

huge differences with the tow module. It simply detects when something is plugged into the wiring harness. It changes a lot more than just shifting.


no comparison

Is that on the T1 platform you are seeing huge differences? Any explaination of the differences? Ie. Throttle map change, up shift changes, down shift changes, converter lock changes, gear hold on hill descent...etc?

Has anyone reverse engineered the signal that tells the "front" (ECM, TCM, CCM) computers that the module is connected? I am hoping that it is not a canbus signal and it is a simple 1/0 input that can be tricked into tow mode. I know that is hopeful thinking considering the platform...

 

[volkswagens-for-life]

I have not a single clue on the T1.

The differences in tow mode are exponential. You should be able to look up a comprehensive list but it changes the throttle mapping, shift mapping, the alarm mapping for the vehicular alarm, it adds additional stability control to the vehicle and also the trailer, it adds a ton of extra abs and braking maps to the system, Etc

 

[suiteskull]

Well, I bit the bullet and decided to get a tow module off of eBay. It appears to have the connector and a short pigtail so hopefully I can get it spliced into a flat 4 pin and see what all the "factory tow package" hype is about. I really hope it makes a difference in, at least, the shift strategies (which was my biggest complaint)...

 

[gryhnd]

Well, I bit the bullet and decided to get a tow module off of eBay. It appears to have the connector and a short pigtail so hopefully I can get it spliced into a flat 4 pin and see what all the "factory tow package" hype is about. I really hope it makes a difference in, at least, the shift strategies (which was my biggest complaint)...

I'd suggest you hook it up to the standard 7 pin, THEN use a 7-4 adapter. Keeps your options open that way and reduces any potential for mis-wiring trying to get it to 4 right off the bat.

 

[suiteskull]

I'd suggest you hook it up to the standard 7 pin, THEN use a 7-4 adapter. Keeps your options open that way and reduces any potential for mis-wiring trying to get it to 4 right off the bat.

Good call, I forgot these wire direct to the 7 pin adapter unlike my current "Tee in" system that goes to 4 pin that I adapt to a spaghetti mess 7 pin. Sad thing is I just replaced the "plug and play" light converter a couple months ago...
Thank you for the reminder/education.

 

[suiteskull]

Just hooked up the module. Mine came with the 16 pin connector (T7) and pigtail. Here is the wiring color breakdown, it is NOT standard colors for most wiring harnesses!
Green - Tail lights
Brown - Right stop/turn
Red - Left stop/turn (larger red wire, smaller red goes to the green connector for brake controller brake light reference, I think, not tested yet)
Yellow- Reverse lights
Black - 12v +
The system will not recognize a trailer unless there is a light load (ie. bulb with ground) on one of the following wires: Tail, Left, or Right individually or all together (obviously)
Note: the system will not output voltage without a load, so you cannot test outputs with out a trailer "recognized"
Beware: 12v will be hot from the moment you connect the module up.

 

[suiteskull]

Here is a complementary view if the back of the VW type connector (T7 in the wiring diagram) with the connector numbers written in.
This is the same view as looking at the connector side of the trailer plug shown above.
So VW (T7) pin 1 is "7 way" pin 5 ( left turn), Pin 2 is pin 1 (ground) and so on...

 

[suiteskull]

I take back my comment on the wire color not being standard. Apparently it is standard on the 7-way RV "standard" wiring shown in the picture: