mudman2

this is what I got from the manufacturer

Hello Mike;
The Prodigy sends out trace voltage every 3 seconds or so and it will
affect this Cayenne this way. You can take the red wire from the
Prodigy and connect it to the brake switch directly and not go through
the factory harness and that will stop this from happening.
The wire you would be looking for is the black/red stripe at the brake
switch.
Any of the other controls would not do this as they do not have the
diagnostics. This would just be the recommended wiring for this Prodigy
brake wire.
If there is anything more I can assist you with, please let me know.
Have a Great Day !!

Kevin M.

I did the fix, now the damn Cruise Control doesn't work.. I haven't checked it it popped a fuse, but I think the brake controller is telling the car that the brake is applied therefor not activating Cruise control!! I'll let you guys know what I come up with

mudman2

Oh your kidding Kevin, I was lined up to do that next weekend.

Sounds like the manufacturer put out a fix without trying it.

GM Austin

I have it wired and mounted per Tekonsha specs and my cruise control still works. I don't know about the brake controller, I haven't had a chance to test it yet. I just had time to mount the Prodigy and then I was on the highway for a couple of hours Sunday. I can report that the cruise control is fine and I believe I do have the wiring correctly done according to the Tekonsha notes. I will be testing the controller this week so I will let you know.

There are four wires on that brake switch. Red seems to be hot and the red/black on the opposite side seems to be the one you want to wire to. I don't know what the two middle wires go to but I'll bet at least one of them goes to the cruise control. Is there any chance you have a loose strand going over to one of the middle wires?

Kevin M.

I will double check it, I'll leave the Prodigy attached and try it out, but if it works that tells me there is a problem when a trailer is attached and power is on to the unit.

Kevin M.

Well no trailer attached, no Cruise Control... unplugged the Prodigy... no Cruise Control, next is check for a CC fuse, then check wiring..

wingless

Both the red and the red / yellow wires are connected to +12VDC. The black / red wire is the normally open brake switch contact and the red / black is the normally closed brake switch contact.

These +12VDC wires are fed by fuses in the left panel. One is fuse F38, the other is fuse F26.

GM Austin

Thanks Wingless! I believe the correct wire is the one on the far right in the photo below, which I should have called black/red; black with a red stripe. Current only flows in this wire when the brake is applied.

tstarke4

The information on this forum has been a tremendous help so far. Thanks to everyone. My question: Can anyone tell me where the brake light switch is? I can hear a faint clicking when I move the pedal by hand, but I don't see a switch anywhere.

GM Austin

Here is a photo of the brake switch.

ltc

I realize I'm the black sheep of the forum, but I still don't see why someone would put themselves thru all these gyrations just to get a Prodigy to work in a Cayenne.

A (modern) brake controller is a brake controller.

Just buy a standard brake controller, plug it into the 4 pin connector provided/designed for this purpose (just like every other vehicle with a brake controller connector) and be done with it.

I have a feeling that PAG/PCNA would not be supportive of the above mods with regards to vehicle warranty.

GM Austin

I agree Lewis. The way I got to this point, and this probably applies to others as well, was by researching brake controllers and finding general agreement that the Prodigy was the best, and then buying it. Then, after the purchase, we find several issues with the installation in the Cayenne. If I had known up front there would be problems with the Prodigy, I would have bought something else.

skl

I bought a good analog unit from a local hitch place that also sold the Prodigy for a little less money, used the VW plug for a real neat installation and it works fine- agree with Lewis as well...no hassles.

tstarke4

My '05 CS does not have a brake light switch as depicted in the photo posted by GM Austin. I wired the brake light switch to the factory four wire connector and will test it today.

38D

That's the way I went. Sure it's not digital, but it works just fine.