So Easy A Porsche Dealer Could Do It: Cayenne Brake Controller Install
For a much more in depth write up, please see the tech article I wrote for our local Kansas City Region PCA. It can be found at www.kcrpca.org and click on the newsletter archives and find the September-October 2012 issue, download it and go to page 6. Everything is explained in more detail.
A good buddy of mine brought over his 2011 Cayenne S for a trailer brake controller install the other day. The idea of a brake controller is to activate the electric trailer brakes when you hit the brakes. This helps to slow your speed smoother and quicker with a heavy load behind you. There is a lot of misinformation out there on this install, mostly dealing with the mystery factory wiring harness that the brake controller plugs into. For years, guys have sworn that the plug wasn’t there on their Touareg or Cayenne, but in reality, it has always been there, but the plug can be really hard to find under the dash. The install has changed slightly through the years, but overall is pretty straight forward.
We are using a Prodigy P3 brake controller which right now is considered one of the best controllers out there. I use one in my rig and it is a fantastic unit. At about $150, it is well worth the money.
As the sun goes down, we get to work 😉
The first thing to do was the install the factory 7 way plug at the trailer hitch. The wiring is there, just remove the dummy plug and plug in the 7 way receptacle.
Up above the brake pedal and to the driver outer side resides the FACTORY harness connector to install the brake controller. Using the male VW portion of the connector (gasp!), we splice in to the prodigy P3 brake controller harness and match up the wires as needed. Essentially we are putting a connector on the end of the Prodigy P3 brake controller wiring harness that plugs direclty into the FACTORY wiring under the dash. Since the new Cayennes and Touaregs no longer use a brake light switch on the pedal, you have to use a relay that feeds of the signal from the master cylinder sensor. It all comes through the FACTORY wiring harness, so no big deal. Power to power, ground to ground, trailer to trailer, brake signal to relay, power to relay, ground to relay and relay to brake signal on the controller. Pretty simple right 🙂
Here is the relay wired inline in the brake controller harness. After a little work, we had a fully functioning brake controller that is removable by simply unplugging the harness at the FACTORY connector under the dash 😉