Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche Cayenne & Macan Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
Factory Tow Module/Curt Trailer Hitch Installed for $440

Part 1 of 2

I know I am not the first person to tackle this project but I wanted to share my experiences with the group while it is still fresh in my mind. Hopefully my summary will help out the next guy. If you are going to tackle this project I recommend you locate on the web a copy of the Porsche AFTERSALES installation guide for the tow system. Unfortunately, I do not know how to attach it here.

I custom ordered my (US Spec) 2005 Cayenne V6 in November of 2004 and took delivery of it in February 2005. Like an idiot I did not have the factory install the tow system. At the time the option was about $1000.

In 2011 my body guy installed an aftermarket CURT tow hitch for free! The cost of the hitch was $180, ordered directly from CURT via their website. I am not by any means a towing expert, but my impression of the CURT tow hitch was very favorable. It seemed to be well built, beefy and had a nice powder coat finish. I am aware of three main differences between the CURT tow hitch and the OEM product.
1) The safety loops used to connect a chain from the trailer to the hitch run perpendicular on the CURT hitch and are parallel to the receiver on the OEM product.
2) The CURT hitch does not have provisions to connect the bracket of the 7 blade Pollack electrical connection to the hitch. Currently my Pollack connection is zip tied to the safety loop until I can work out a solution for the metal Pollack bracket.
3) The OEM tow hitch is rated at 7,700 lbs. towing capacity, and 660 lbs. tongue weight. vs. the CURT unit at 6,000 lbs. & 600 lbs.

The CURT hitch does not have accommodations for the tow eye on the hitch. However, I suspect if I ever needed to flat bed the SUV it would make more sense to utilize the tow hitch than a tow eye.
Below are photos of the installed CURT tow hitch. I came across quite a few write-ups on how to install both aftermarket and OEM tow hitches. My CURT tow hitch required a little bit of trimming of the bumper cover, but if done properly, not even noticeable. In fact, you need to be underneath the car to see the cut.









My tow hitch worked well to secure a bike rack on the rear of the SUV, however I found a need to begin towing a small trailer. Therefore, I needed to get the appropriate electrical connections for trailer lights. There are several ways to accomplish this, obviously the OEM surge brake system and an aftermarket solution.

Some of the contributors on other forums state that for towing small trailers without brakes, there is no need for the factory OEM surge brakes, and splicing into the existing tail lights is sufficient. Again I do not have any experience with this method and cannot attest either way how well it works. My concern doing it this way is that it may trigger a warning on the dash.

Others on the web report using aftermarket products. A couple that come to mind are Prodigy and the Curt brake controllers, but a search of the web would reveal even more. Again I do not have any experience with these products.

People who had the OEM surge brake controller commented how well they towed large trailers and liked the fact the tow controller module interfaces with the dash. In the event a trailer light burns out there will be an indication on the dash, and when you use the turn signals there will also be an additional blinker on the dash.

I decided to go with the Factory tow module route . . . Our host sells all the necessary hardware. The factory AFTERSALES installation documentation lists all the major hardware and accessories needed to properly install the hitch and electronics. Below are the major components
1) 955-618-040-10 Control Unit -$218 from our host
2) 955-612-506-00 Wiring Harness -$236 from our host
3) PNA-955-118-93 trailer hitch connector -$18 from our host

My research revealed that there are also another part numbers for this project. The Touareg uses the same system as the Cayenne. Since the information was so sketchy on how to do this project, I was worried I would buy hundreds of dollars of new hardware just to have them collect dust in my garage. I was able to pick up a “new” Westfalia tow module controller and wiring harness for $260 delivered which the seller claimed he bought new but never installed for a 2004 Cayenne V8. In hindsight, worked well for me, however, if I had to do it again I would have bought the hardware new because there wasn’t much difference between buying the Westfalia parts from a third party than buying new from Pelican. ALSO, here is an important point, my research showed that there are several used tow module computers available on Ebay, but if you go that route be careful what you buy. There are several early versions of the tow module available. Some forum contributors stated that early versions needed to be reprogrammed/reflashed at the dealer. I wanted to avoid a trip to the dealer at any cost. The Westfalia part number for the tow controller is
7L0 907 383 (Version designated by a Letter)

The part I bought was 7L0 907 383 F. This is an uncommon tow module controller because it has the ability to control the retractable tow hitch. Most tow module controllers have two connection blocks, the F version (or versions that control the retractable tow hitch) have a third connection block. In my install I did not use the third block and the controller still worked fine, (no errors on the dash or on the Durametric Scanner).

The wiring harness was also a Westfalia product, part number
327 007 321 003

Though this part was advertised as new, one of the pigtails had two of the connection tabs broken. However, fortunately for me the pigtail still plugged snugly into the appropriate connection block AND it was the easily accessible connection block, NOT the one buried in the side panel. In the event this block works itself loose, it is as easy to replug as accessing the CD changer. In addition, buying a used wiring harness has its pitfalls because you do not know how carefully it was removed. I was able to find several used tow module controllers on Ebay (mostly from Europe) but wiring harness were rare. I did contact several Ebay sellers if they had the wiring harnesses and all of them said they were not available.

In addition to these three main components already discussed, there are several other small parts needed, as listed in the AFTERSALES literature. Fortunately for me, I have a garage full of the appropriate accessory hardware, however, I verified everything in the AFTERSALES literature is available from our host.





Electrical Connections:
The wiring harness plugs into the SUV in two locations, one very easily accessible, the other one- not so much. The first one is located in the side access panel, underneath the CD changer, against the inner rear side of the vehicle towards the very back of the SUV. In my Cayenne, there were three connection blocks, two were already being used, the third one was green and the green pigtail from the wiring harness easily plugged into this connection.

The second place the wiring harness needs to be plugged into is the tow module controller. The tow module controller then is mounted in front of the CD changer in the right side trunk panel on the passenger side. There you will find wrapped in grey foam is a red pigtail which then plugs into the tow module controller. This assembly is mounted in an already present mounting bracket. The controller is mounted vertically with the connections pointing towards the center of the SUV.

I considered splicing the red pigtail and lengthening it so I could position the tow module controller in the open space below and behind the CD changer, but I decided against it because of potential failure of the various splices. After weeks of researching how to remove the side panels to no avail Wayne posted a motherlode of tech articles on this forum how to replace the rear hatch shocks. This write-up was very well written with detailed photos.

Pelican Technical Article - Porsche Cayenne - Rear Hatch Shock Replacement

However, the process of removing the side panels is a bit tedious so before I tore apart the SUV I wanted to test out the hardware first.

I got lucky, the red pigtail which plugs into the tow module controller was located towards the front of the CD access panel, NOT wrapped in the grey foam as described on the Web. I had the dealer install my XM Satellite radio, and they may have removed the tow pigtail and placed it where I found it. (See Photo)



It was very simple to plug this pigtail into the tow module computer; next I plugged the green pigtail into the green connection behind the CD changer. My wiring harness already had the 7 blade Pollack electrical connector in place, so I was ready to test the system.

Using a Durametric (Version 6) scanner I was able to verify the installation by using this diagnostic tool to identify the controller and run diagnostic tests. The scanner correctly identified the part number and version of the Westfalia tow module controller and diagnostic tests verified the tow module controller was working properly.

END OF PART 1
__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A

Last edited by RNajarian; 02-10-2014 at 07:38 AM..
Old 01-16-2014, 02:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
Part 2 of 2

Part 2 of 2

I then used an adapter to convert the 7 blade Pollack RV connection to a 4 pin trailer connection. There I plugged in a Harbor Freight LED trailer light to test the function of the system. To my dismay the lights flickered and flashed randomly, indicating an obvious problem. Applying the brakes, and turn signals made no difference. At this point I had that sinking feeling.

Fortunately, further research revealed that Cayenne (and other European vehicles) were not compatible with LED trailer lights. Apparently the problem lies in the fact that the LEDs draw so little energy and fools the system that there is a problem. The solution is using an adapter that adds resistance to the system to fool the tow module controller that you are using incandescent lights rather than the LED trailer lights.

I then hooked up a set of incandescent lights to my Pollack connector and the system worked as designed!!

At this point all that was left to do was remove panels and properly install the hardware. Refer to the AFTERSALES installation guide for diagrams and illustrations of what I am about to describe.

Once you remove the EZ access panel for the CD changer, you will notice an oval hole underneath the area of the right side tail light. This hole is at the rear most portion of this access area on the same plane as the bumper. In this oval hole is a cream colored foam insert, carefully remove this foam. Once removed you should see a rubber plug. Your wiring harness will have a replacement plug which allows the wires of the harness to pass through (refer to the photo). Once this original rubber plug is removed, go underneath the corner of the car on the right (passenger) side and feed the pigtail that connects to the control unit through the hole. You may need to rotate/twist/turn the pigtail to fit through the hole. Then feed the harness through and also pass the green pigtail through the hole.

Once this is done go back inside the car and pull the harness about ˝ way through. For the time being, tuck it in the CD recess while you tackle the biggest pain of the entire project.

Removing the right rear panels. My best advice is be patient. Read Wayne’s write up on how to replace the rear hatch struts. Consider a complimentary gain by replacing the rear hatch struts with QUALITY replacements while the panels are removed. This is a job you want to do as infrequently as possible. Follow Wayne’s directions, the photos really helped me understand what I was doing. One good thing about this part is that once you remove the rear headliner panel, the D pillar, the C pillar, and the rectangular tie down trunk floor piece you will have allowed yourself enough wiggle room to fit the tow control module in. You do not need to remove the entire side panel, just enough to squeeze the hardware in.

The AFTERSALES instructions direct you how to route the wiring harness and mount the tow control module. The tow control module has a prepositioned bracket in which the unit mounts vertically with the connections facing towards the center of the car. The bottom slips in to a groove and the top is secured by a nut and bolt (or a screw and the clip on tab-illustrated in the AFTERSALES instructions).

Once the tow control module is in place make sure the vehicle red connector and wiring harness are plugged in to it, then plug in the green pigtail into the green connector in the box behind and to the back of the CD changer.

Next, place the Pollack 7 blade electrical connector to the left (driver’s side) of the tow hitch. Run the wiring harness as far from the muffler/exhaust as possible. There is a heat shield (presumably to protect the bumper/rear parking sensors from the muffler exhaust heat. Run the wiring harness on the cool side of the heat shield and secure it as you see fit. Remember to replace the rubber plug in the hole you passed the wiring harness through. Replace the cream foam in the oval hole, the replace all the panels you removed to access the tow module controller bracket (Refer to Wayne’s write up.)

The final task is to appropriately secure the 7 blade Pollack electrical connector to the left of the tow hitch. I am still figuring the most esthetic way to do this with my CURT hitch. The OEM hitch makes it easy as there are mounting holes for the Pollack electrical connector’s bracket.

That’s it! I hope this summary helps anyone who decides to install the OEM surge brake system. The four major lessons learned in this project were
1) The rear trunk panel Is one pain in the butt to remove
2) OEM Porsche tow modules do not work with LED lights (NOTE: Porsche has known of this issue for some time and likely has resolved the problem for later Model Year Cayennes (circa 2012??)
3) I did NOT need to have the dealer program my tow module. Of course my Cayenne is a 2005 maybe other years are different.
4) I would recommend new hardware in this project, or at least inspect your wiring harness for any damage, and if buying a used tow module controller get a later version to eliminate the need to visit the dealer for a reprogram/reflash.

If anyone has any questions please feel free to ask me, I hope this helps someone

Photo of the wiring harness used


This Photo is of the tow module control unit prior to connecting to the mounting bracket. The visible connection is for the tow hitch retraction system. Not present in most of the tow module control units


Photo of the tow module control unit installed
__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A

Last edited by RNajarian; 01-16-2014 at 03:18 PM..
Old 01-16-2014, 02:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Jan 2005
Location: Gilroy, California
Posts: 3,222
Garage
Good job, I installed my own CURT after I bought my Cayenne, it was fun.
__________________
Its easier asking dumb questions than fixing dumb mistakes
1974 Porsche 911 Coupe, RSR Project
1976 Porsche 911 Targa, Black
1986 Porsche 911 Carrera, Black
2006 Porsche Cayenne S, Black
Old 01-16-2014, 08:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
First Two Pages of Cayenne Tow

Here are the first two pages (of 8) of the Trailer Hitch Installation Instructions. The entire document can be found on the Web after a little search

__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A
Old 01-21-2014, 02:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
More Install Photos

Here are a few more photos of the installation of the OEM Factory Surge Brake Controller


This photo is of the rear passenger side of the vehicle with all the paneling removed. The brake controller is to the immediate left of the CD changer. The black connection is part of the wiring loom which goes to the hitch. The red pig tail in the middle is from the SUV itself, and the bottom turquoise pig tail is the optional retractable tow hitch wiring. (Note: Photo credit from internet)


This photo is a close up of the brake controller unit. Note the EXTRA (third) connection block on the bottom which controls the retractable tow hitch (Note: Photo credit from internet)


This is a diagram of the installation of the brake controller unit


The following photos are more detailed factory installation instructions










Finally, here is a diagram of the Pin Out for the 7 Pin Pollack connector
__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A

Last edited by RNajarian; 04-04-2014 at 05:48 AM..
Old 02-10-2014, 07:23 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Apr 2018
Posts: 4
No Brake Lights

So I did the install and it all went great. Dashboard says the signal lights work, tail lights work but I have a big question mark on the dash and it tells me to check the trailer lights and I have no brake lights. I have double checked all my connections but still not brake lights.
Help please.
Scott
Old 05-23-2018, 01:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
What type of trailer lights are you were using? My car which is a 2005, does not register the LED trailer lights at all. So that it will indicate on the dash that the lights are burned out.

First thing I would check is the type of bulbs you are running.

Second thing I would check is whether or not the trailer computer has been activated in the car’s brain. I know the Durametric scanner has the ability to activate the trailer computer. But when I did my car I didn’t need to do any of that. It automatically recognized the trailer computer and all was well.
__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A
Old 05-23-2018, 04:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Apr 2018
Posts: 4
It had LED lights and they flashed all the time but I changed them to indondesent bulbs and the parking lights work, turn signals work but nothing from the brake lights.
Old 05-24-2018, 02:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
My other ride is a C-130J
 
RNajarian's Avatar
 
Join Date: Jul 2004
Location: Southern California
Posts: 1,160
Garage
What year is your car? I am by no means an expert on this but are you connecting to the trailer using the 7 pin Pollick connector directly or with the adapter that converts it to four pins?







__________________
1975 911 Targa S 3.0
2005 Cayenne Titanium Metallic
2010 Mercedes-Benz E350 2012 Mercedes-Benz C350
Previously Owned Art from Stuttgart
2000 Boxster -1983 911 SC Cab -1984 944 N/A
Old 05-24-2018, 05:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 12:37 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.