Have 2004 with factory towing setup. Cannot get lights to work on trailer. I get blinking with test light. Trailer is fine. I was told it may be the tail light converter? Anyone been through this ?

 

If the trailer lights are LEDs then you will need an adapter as the early Cayenne's did not play well with the LEDs.

 

Not LED. Looks like it may be the Module. Will try to find one. 7L0 907 383G

 

Getting to the module is a pain in the **** - gotta take our the rear seatbacks, rear pas side quarter trim panel and all the associated panels around it (C & D pillar trim, trunk top and bottom trim, spare tire cover). Better make 300% certain your trailer wiring is good, or better yet hook up a different trailer to test.

If you have Durametric or another similar scan tool, you can read any error codes from the tow module for clues and also there is a function to turn on each trailer light manually. Good for troubleshooting.

I had a similar issue, turned out to be a broken wire in the trailer wiring loom that would lose connection depending on how you wiggle the wire. I'd put it on the car and it would not work, take it off and it worked just fine with a test light. Finally saw an inconsistency in my test light testing and traced it down to a wire at the light entrance that was chopped off by the plastic housing. I was testing from the trailer plug to the bulb socket directly.

 

I see the control module in the rear hatch boot. Looks like the dealer unscrewed it and left it hanging there. Then charged me 119.00. I read a thread that said if I need a new one , I should get the G series (7L0 907
383G). I hate to buy one and find out that's not the trouble. I will examine the wires at the hitch and see if there's anything there. Right now.....I have the 7 pin hitch. With a test set the light will blink off and on. I don't have a scan tool.

 

If you determine it's the control module there are plenty on eBay. Some even come with a warranty and they're pretty inexpensive compare to the dealer.

 

I was thinking I would disconnect it and see if it might reset. Apparently the 'E' series I have now is the older plug and play version.

 

Very interesting service you received at the dealer... Does it at least still have all the connectors plugged into it? One of the connectors goes to about above the rear wheel, didn't look like there was enough wire to "relocate" the module to the boot.

There was E, G, and even N sub-revision modules on newer cars. Each has newer firmware. When I did my tow hitch install, I could not find an answer but my concern was that if I get one too new it would require a trip to the dealer to re-program to work with the rest of the car, so I got a G one from a 2008 vehicle, which is what mine is. No issues. In your case, I personally would stay with 2004-2007 ones in your case, as there was a significant electronics logic update starting with the facelifted 2008 cars.

Your test light probably doesn't have enough amperage, the car decides the light bulb is blown and cuts the power. Pig-tail a higher draw bulb and you can check if it stays on.

 

Good info. This is what I have in the boot. 2 cables connected.

 

"D" revision? I haven't even seen one like that... Must be pretty old. The third connector I think is supposed to be unplugged for US models - it's for some European stuff.

Up to you at this point whether you want to diagnose and get to the bottom of the problem or roll a dice with a $50-100 used one.