Trailer lights issue with 2006 Cayenne
02-16-2014, 12:27 PM
#1
3rd Gear
Thread Starter
Trailer lights issue with 2006 Cayenne
Wife and I went to go get our first ever travel trailer, only to be disappointed.
We have the factory tow package installed with my only having to buy the 7 pin adapter.
We did our walk through, signed papers, bought a whole bunch of stuff and were happy until we were ready to go home with the trailer. Hooked it up and turned on the parking lights. Those worked... Tried the turn signal and just sort of got a dimming of ALL the lights on the trailer, all the vehicle lights still worked though. Tried the same with the brake lights. Technicians came out and checked all the trailer lights and wiring. That was all good. Went to our vehicle and they were getting the constant dimming sort of flash of the lights on ALL pins of the harness in the back of the vehicle. So NONE of the brakes or turns work. No they are not LED lights...
Luckily the Porsche dealer was literally right next door, so I went over there and a tech was available to look at the car. She said it was usually coding issues. Well, she checked the coding and it was US spec. She troubleshot for about an hour and couldn't find anything. She said there were no codes and everything looked "good" through her computer but it doesn't check the outputs of the towing controller.
When I got home, I ripped apart the walls of the cargo area where the towing controller is located and ended up finding fuse 1 on the passenger side of the vehicle was toast. It was a 15A fuse labeled "Towing Attachment." GREAT! Found my issue?! No I didn't... Same thing... Fuses are all good now and still having the same problem. Which again, the lights come ON for the parking, but no brake or turn. Only a steady fluctuating dimming of the parking lights.
I ordered a new trailer control unit (factory one) and will go from there. But I was wondering if anyone knew of a wiring diagram or the path all of the signals take. Does the input for the control unit come straight from the vehicle lights or does it run through another computer before it goes to the trailer control unit. Anyone have a pinout of the control unit?! I have found two wires are constant hot, one that is hot with ignition on and the brake signal. So, I had a solid 12V going in on the brakes but couldn't find the turns. If I had good brake lights then the controller should have recognized that and put it out to the trailer. I didn't find a signal from the turn signals at all at the control unit but have a feeling that is why you need the control unit is because they may be can-bus signals and not measureable with a test light or DVM.
I really hope this is the control box and not something else before that but I want to know if anyone has any sort of help with this since the dealer couldn't diagnose it with the limited time that we had. (They want me to drop it off for another 3 hours of diagnostics.)
Thanks a ton guys!
We have the factory tow package installed with my only having to buy the 7 pin adapter.
We did our walk through, signed papers, bought a whole bunch of stuff and were happy until we were ready to go home with the trailer. Hooked it up and turned on the parking lights. Those worked... Tried the turn signal and just sort of got a dimming of ALL the lights on the trailer, all the vehicle lights still worked though. Tried the same with the brake lights. Technicians came out and checked all the trailer lights and wiring. That was all good. Went to our vehicle and they were getting the constant dimming sort of flash of the lights on ALL pins of the harness in the back of the vehicle. So NONE of the brakes or turns work. No they are not LED lights...
Luckily the Porsche dealer was literally right next door, so I went over there and a tech was available to look at the car. She said it was usually coding issues. Well, she checked the coding and it was US spec. She troubleshot for about an hour and couldn't find anything. She said there were no codes and everything looked "good" through her computer but it doesn't check the outputs of the towing controller.
When I got home, I ripped apart the walls of the cargo area where the towing controller is located and ended up finding fuse 1 on the passenger side of the vehicle was toast. It was a 15A fuse labeled "Towing Attachment." GREAT! Found my issue?! No I didn't... Same thing... Fuses are all good now and still having the same problem. Which again, the lights come ON for the parking, but no brake or turn. Only a steady fluctuating dimming of the parking lights.
I ordered a new trailer control unit (factory one) and will go from there. But I was wondering if anyone knew of a wiring diagram or the path all of the signals take. Does the input for the control unit come straight from the vehicle lights or does it run through another computer before it goes to the trailer control unit. Anyone have a pinout of the control unit?! I have found two wires are constant hot, one that is hot with ignition on and the brake signal. So, I had a solid 12V going in on the brakes but couldn't find the turns. If I had good brake lights then the controller should have recognized that and put it out to the trailer. I didn't find a signal from the turn signals at all at the control unit but have a feeling that is why you need the control unit is because they may be can-bus signals and not measureable with a test light or DVM.
I really hope this is the control box and not something else before that but I want to know if anyone has any sort of help with this since the dealer couldn't diagnose it with the limited time that we had. (They want me to drop it off for another 3 hours of diagnostics.)
Thanks a ton guys!
02-17-2014, 05:40 PM
#4
Addict
Rennlist Member
Rennlist Member
Electric trailer brakes?
