akolluru

Hello, I have been through a bunch of threads on here trying to find a reverse signal that I can use to plug into pin 6 on the PCCM. Is there one that I can steal from somewhere near the front or is the only option to pull one from the rear light harness? I would prefer not having to run another wire from the back of the car to the front. Thanks!

smrpr

I have a couple of messages from the Android HU thread saved in preparation for my install. Hope these help you, but I haven't tried it myself:

CBRich

Not sure if you're already starting with a rear view camera installed, but if you're running new most cameras will have an included power wire that runs with the RCA to the front in the loom. You can use this as long as you're fine with the camera being powered directly by the reverse wire, which can cause a momentary "lost signal" display as you shift out of reverse.

funnelofdoom

You can also tap off the reverse wire in the rear control module. According to schematics, the wire is black and blue.

As a tangent, manuals actually do have a canbus reverse signal. This notifies the rear view mirrors to drop down when reversing and to notify the rear control module to turn on the lights. There is no direct connection from the transmission reverse switch to the rear module or lights.

There is also a reverse signal required by the auto dimming mirror (disables them
for clear view), but that is actually directly tied to the reverse signal in the rear control module that sends power to the reverse lights.

The canbus signal is probably just different and Porsche didn’t intend for us to add cameras.

akolluru

Thanks guys for the help!! Unfortunately the camera I bought didn't come with the a wire that ran with the cable so needed a power wire. I ended up tapping the signal from the taillight and running that wire along the RCA since I was in the area and didn't want to splice the original cables more than once.
@CBRich it does show no camera momentarily but it's not that big of a deal for me to worry about it.

myw

i always figureded the reverse mirrors dipping down gets its 'reverse input' also from the rear module under the drivers seat.

if it were the same porsche reverse canBus trigger that's used in the
- 997.1 tip
- 997.2 6spd + PDK
- 955

then the oem pccm+ should flip to reverse camera mode in the 997.1 6spd cars ... except that it does not.

funnelofdoom

Sorry, I'm not implying it's the same signal, it most likely is not. The 997.2 has a lot of differing canbus signals. I did study the schematics for various things, including the PCCM backup cam install, and there are no direct signal lines going to the door control units, just canbus lines. There is a connection between the rear view (interior) mirror and the backup signal, I'm assuming to turn off the darkening feature when backing up. The central mirror then sends a differential actuation signal to the side mirrors to darken as well. So it is possible that signal is some type of low bandwidth data signal that tells the mirrors how much to darken and also has a signal to indicate if the car is in reverse. There is no direct signal from the rear module to the mirrors.

However, according to the schematics I have available, the reverse signal from the transmission does not go to the rear control unit, it goes to the on board computer network control unit. The only way the rear module would know the car is in reverse is if the OBCNCU sends a signal over CAN that it was in reverse so the rear module could then activate the reverse lights. This is why I conclude that there is some CAN signal to indicate reverse in the car. However, obviously the PCCM is not programmed to read this signal. It only reads the signal from the automatic transmission of the TIP and 955. The 997.2 has a lot of different CAN signals so that is a different topic altogether. Since the CAN signal for reverse is generated from the transmission in the automatics and in the OBCNCU in the manual 997.1, it is not much of a leap to assume that they are different and that is why the PCCM cannot read the manual trans CAN reverse trigger signal. The PCCM backup cam functionality was only included for the 955 since they had to preserve that functionality. People with Tiptronic 997.1 cars are just lucky it happens to use the same signal as the 955. We're also lucky that they preserved the Android head unit functionality of supporting a direct 12V trigger so that it is not very difficult to trigger a backup cam from our manual cars.