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As I wanted to fit the retractable towhitch onto my 958 without breaking the bank buying new, I thought I'd go down the route of seeing what else would fit that I might pick up used.
Turns out the retractable hitch for the 7P Touareg is a perfect fit for the 958 Cayenne, bolted it on today, using new bolts (you'll need these as the crash bar that you'll remove uses shorter bolts) but no requirement to do any other alterations, the towbar itself is a simple fitment.
Knowing that I'd need electrics, I bought a genuine Westfalia electric harness advertised as being for the 958 - this is where I've hit problems and need some help.
There are two terminal blocks on the wiring coming from the towbar into the car, one black and one green. The green one plugs into a terminal already present in the car and connects perfectly, the black one is supposed to plug into the module that I have, along with a red plug that is already fitted in the car but not connected - neither of these connecters will fit into the module.
Is there any kind soul out there with a 958 (mine's a 2013 4.2 SD) who would be prepared to look at their towing electric module inside the rear wing and get the part number from it for me as I could do with confirming if I have the correct module or not!
In case anyone should follow on after me, I thought I's update this post with the saga that has been the fitment and activation of this retractable towbar.
The first point to note is that the Touareg bar I have bought does not electrically winch up and down from its hiding place, the button inside the tailgate just releases the electronic lock, the swan neck is then pushed into place and the electronic lock kicks in to keep it there.
That said...
The control module that I purchased originally turned out to be the wrong one, it was for a fixed bar, not a retractable one... this is easy to tell in hindsight as it has 4 connectors on it - it was for the 958.2 Cayenne and had the part number 4MO907383F
The correct control module turned out to be 7PO907383C - this has 3 connectors on it (there is also a module with only 2 connectors, this is for the fixed towbar)
If at all possible, try to get the module supplied with the wiring plugs and, ideally the switch and loom that controls deployment. This is rather important as the loom is not available as a spare part from Porsche. I paid £130 on ebay
The part number for the switch depends on whether you have air suspension or coils - if you have coils, it is 958613164006N3 - the N3 at the end of this is important as it's that which signifies which exact switch you'll get - it's about £50 from the dealer, I struggled to find one anywhere else.
By now you've got the bar mounted on the car (no cutting was required, just the longer bolts as noted previously) and the cables from the bar routed through the ready made hole in the shell, grommet secured in place.
The control panel mounts behind the Bose amp, either Zip tie it in place or there is an official holder available from Porsche I believe.
The large black plug and the red plug from the towbar connect into the module, the green plugs into the terminal already in the car.
The problematic connector is the blue one... it has 6 terminals that connect to the switch and one that connects to the fusebox on the end of the driver's side dashboard (RHD car)
If you did not get the blue plug with the module, it's readily available from a breakers yard, fitted to the central locking module of a 2010 era VW Polo. Its part number is 6Q0972883C
If your blue connector did not come with the relevant number of pins then you'll need to order the following from Farnell or similar
Blue connector pins 4-8 - Farnell 1863427
Blue connector pin 10 - Farnell 3792138
Blue connector pin 11 - Farnell 1772733
The switch also does not come with the plug to connect the wires, this is hard to find but has the part code
The connector pins for this are part code
With the exception of the red wire, all wires are 1mm dia, I ordered 1m of each (and 4m of red 2mm) from 12v planet along with a fuse tap to enable connection to the fusebox as noted above.
Once all this is connected up, the button will release and engage the swan-neck lock correctly. I'm still looking into whether the bar should actually motor down (and back up) into place as mine currently doesn't do this.
There is also coding required which I've not had done yet either.
Last edited by derekmines; 10-23-2022 at 03:10 PM.
You will need the module. As I noted above, be very careful with the numbers, there are number of different modules for cars with and without the deployable bar etc - I would buy a Cayenne one rather than Touareg as in my research I found various posts that the Touareg module doesn't work properly and the guy who will be coding mine (eventually) also noted that PIWIS often doesn't play nicely with Touareg modules even though they are superficially the same.
I also read a post that it's better to buy a used module than a new one as the new ones may actually have no config on them at all, meaning the bar won't function at all.
Tow bar prep means that the fusebox is populated with the fuses and that the green connector I mentioned above will be situated in the rear wheel well behind the trim panel.
Did you manage to get the loom that runs between the switch and the module? as I noted above, it's not available as a spare part from Porsche and caused me no end of grief (and a 6 month delay) building my own loom
Mine is currently installed and partially working (the deployment and locking in position parts) however I couldn't get any lights on my trailer. My meter was flat though and the weather here filthy so I've done no testing as to why this might be.
Best of luck in your project, I've retrofitted bars to a half-dozen cars over the years, this is far and away the most complicated.
You will need the module. As I noted above, be very careful with the numbers, there are number of different modules for cars with and without the deployable bar etc - I would buy a Cayenne one rather than Touareg as in my research I found various posts that the Touareg module doesn't work properly and the guy who will be coding mine (eventually) also noted that PIWIS often doesn't play nicely with Touareg modules even though they are superficially the same.
I also read a post that it's better to buy a used module than a new one as the new ones may actually have no config on them at all, meaning the bar won't function at all.
Tow bar prep means that the fusebox is populated with the fuses and that the green connector I mentioned above will be situated in the rear wheel well behind the trim panel.
Did you manage to get the loom that runs between the switch and the module? as I noted above, it's not available as a spare part from Porsche and caused me no end of grief (and a 6 month delay) building my own loom
Mine is currently installed and partially working (the deployment and locking in position parts) however I couldn't get any lights on my trailer. My meter was flat though and the weather here filthy so I've done no testing as to why this might be.
Best of luck in your project, I've retrofitted bars to a half-dozen cars over the years, this is far and away the most complicated.
I have finally managed to get company to make custom loom based on your instructions. Let me know if you manage to find anyone locally which is able to code this as I will be after someone soon
Unfortunately I can't edit post #2 to add this detail, but the plug you'll need for the back of the towbar deployment switch is a TE product with part # 1-1241370-3 and you need 6 pins to populate it, they are TE 5-963715-1
The plug is best bought from Mouser (about £0.78) and the pins are available singly at Farnell for £0.13 each.
Mine is currently installed and partially working (the deployment and locking in position parts) however I couldn't get any lights on my trailer.
Have you had your module coded yet? In my case I got no working lights until the coding was completed. Others have said they did have working lights prior to coding, so it seems this can be hit and miss.
Have you had your module coded yet? In my case I got no working lights until the coding was completed. Others have said they did have working lights prior to coding, so it seems this can be hit and miss.
Had a bit of a setback in that it turned out the module I bought was water damaged and faulty, awaiting a new module now.
You will need the module. As I noted above, be very careful with the numbers, there are number of different modules for cars with and without the deployable bar etc - I would buy a Cayenne one rather than Touareg as in my research I found various posts that the Touareg module doesn't work properly and the guy who will be coding mine (eventually) also noted that PIWIS often doesn't play nicely with Touareg modules even though they are superficially the same.
I also read a post that it's better to buy a used module than a new one as the new ones may actually have no config on them at all, meaning the bar won't function at all.
Tow bar prep means that the fusebox is populated with the fuses and that the green connector I mentioned above will be situated in the rear wheel well behind the trim panel.
Did you manage to get the loom that runs between the switch and the module? as I noted above, it's not available as a spare part from Porsche and caused me no end of grief (and a 6 month delay) building my own loom
Mine is currently installed and partially working (the deployment and locking in position parts) however I couldn't get any lights on my trailer. My meter was flat though and the weather here filthy so I've done no testing as to why this might be.
Best of luck in your project, I've retrofitted bars to a half-dozen cars over the years, this is far and away the most complicated.
I have finally managed to find time to carry out the installation. I think it went fairly smoothly with your instructions. However pressing the buttons doesn’t seem to do anything? Hopefully it’s just the case where it needs to be coded?
Have you managed to find anyone which will be able to code this or are you going direct to Porsche?
I have finally managed to find time to carry out the installation. I think it went fairly smoothly with your instructions. However pressing the buttons doesn’t seem to do anything? Hopefully it’s just the case where it needs to be coded?
Have you managed to find anyone which will be able to code this or are you going direct to Porsche?
Thank you again for all info
I still haven’t managed to find someone willing to code the module but seem to have working lights when I plug a light board from. The operation of electrical swivel is not working but I also think the wiring diagram above for switch is off by two pins.
Maybe derek can advise if this is the one he was using but it seems like switch pins are not in order but 1 3 2 4 5 6. I have now switched the two around and button is flashing and you can hear clicking noise from module when pressing.
Very helpful thread so thank you! I’m still unsure though so any help would be appreciated!
I have a Cayenne turbo 958.2 and believe the correct part no. For the tow bar is 95804480135.
I have tow bar preparation already on the car from checking on vin analytics.
I have found a tow bar on eBay (see pictures). It looks identical just not sure about electrical connections. Will this work for me?
From reading your write up I gather I will need module - 4MO907383F
Then I already have air suspension height switch in the boot so presumably I just buy the tow bar switch that goes next to this. Is there then a loom from here to the module or because there is already wiring here for the height adjustment this will be plug and play.
Then coding to activate and I should be good to go?! Or not?!…
Apologies for restarting an old thread, but I am going through a similar process of installing an electric towbar to my 958.2 Cayenne.
So far I have got a towbar sourced from an Audi Q7 but it looks exactly the same and hooks up fine, the boot switch and 7PO907383G module (used so hopefully it won't need coding).
I am now going through the process of creating a new loom between the switch and module as per Derek's very helpful directions and the wiring diagram.
My issue is the Q7 tow bar doesn't have the green connector - it's just the black connector that goes into the module and a ground. Looking at the wiring diagram the black connector controls all of the functions - trailer pivot motor and trailer socket.
Does anyone know the purpose of the green connector and whether it is needed? Looking at the wiring diagram it could possibly be a brake booster but I don't need that - I'm not aware of any trailers that have that function.
Just to follow up on this to assist anyone doing something similar in the future.
In the UK at least, the green connector provides two ground points and a 25amp live feed. I ended up using the live feed rather than running a separate wire to the fuses in the front and just mounted the two grounds to a common ground.
To confirm the q7 towbar works fine otherwise. The cable is a touch short so you have to be creative with the location of the towing module but other than that it's absolutely fine.
Good luck to all of those looking to do an install in the future!
05-14-2022, 03:47 PM
Touareg Electric Tow Hitch on a Cayenne 958
