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I tested it, seemed to work for me, either that or a got things really mixed up pinwise.
But how would that make sense to have a switched ground?? Serves no real purpose splicing the reverse is already switched and fused..
adding a switched ground does not really add value to that ???
the switched ground - is for the oem 955 rear camera functionality. the backup camera is silly-complicated, not only does it need to turn on, but it also needs a motor to pop out. the pin8 ground input AFAIK is a control GND input that gives the cayenne rear cam system (power + motor) - permission to turn on/pop out (relay system). this is from my research as of late re aftermarket radios using the oem cayenne backup cam.
edit - pin8 GND , is the standard spot on the 6 pin video harness for all android radios - as per the photos of the android harness from a month back.
I tested it, seemed to work for me, either that or a got things really mixed up pinwise.
But how would that make sense to have a switched ground?? Serves no real purpose splicing the reverse is already switched and fused..
adding a switched ground does not really add value to that ???
One way I am thinking of using the switched ground on pin8 is provide accessory power to the camera in the back and use the switched ground as ground for it. It should get the benefit of the 10sec delay and then the circuit will be open.
Last edited by nikandriko; 03-17-2023 at 12:20 PM.
Thank you for posting this - I was waiting for a 3rd person to confirm, and this is exactly why i didn't want to release the rear cam harness yet.
Yes, either you or @svandamme is correct - his testing he had confirmed that pin8 was switched power when pin6 reverse trigger was activated, but from @maxw on his unit - he confirmed that it wasnt the case (not power). As nobody else had chimed in to confirm - and now you are also saying its not power but instead ground.
I was waiting for another person to respond - as having studied it further GND is possible for switched pin8 - as the cayenne reverse camera system uses a GND connection as a control cable that is connected to a relay - its more complicated as the cayenne uses this pin8 GND connection to control the reverse camera motor (as well as the camera power).
Do you have a video of this you can send me?
If what you are saying is true (which I am pretty sure it is) - then the camPower will need to be thru the reverse light wire - as pin8 is a GND (max 200ma) and not power (200ma).
Unfortunately, neither me nor my car mechanic Farley - captured a video while investigating it. We did put the probe to the other pins as well looking for 12V but there was none.
Farley has suggested to me the following options:
Leave the camera powered from the reverse light. Drawback is I get the 0.5sec “missing camera” screen when getting out of reverse.
We provide accessory power to the camera which means that it remains on while the key is on. We can provide accessory from the fuse box, from the back of PCCM or even the tail lights. Drawback is the camera stays always ON while the car key is ON.
We provide accessory power while use pin8 for a triggered ground so that we get the 0.5sec delay and the camera is not always ON. Farley told me that lots of car accessories work with triggered ground vs. triggered 12V.
Would love to hear what you guys think is best.
Last edited by nikandriko; 03-16-2023 at 01:29 PM.
With respect to those who are trying to accommodate an aftermarket amp (non-bose car) I'm wondering if the pin out from an older PCCM unit is the same for the PCCM+ unit:
If they are the same then I could bypass these wires into RCA females to accommodate the line in to the amp. It's frustrating that on aliexpress you can buy the same radio, except for sd card nav , with dedicated RCA amp outs and this unit does not have that option. I suppose porsche felt this is an option for porsches that have not had their audio systems violated .. ?
With respect to those who are trying to accommodate an aftermarket amp (non-bose car) I'm wondering if the pin out from an older PCCM unit is the same for the PCCM+ unit:
If they are the same then I could bypass these wires into RCA females to accommodate the line in to the amp. It's frustrating that on aliexpress you can buy the same radio, except for sd card nav , with dedicated RCA amp outs and this unit does not have that option. I suppose porsche felt this is an option for porsches that have not had their audio systems violated .. ?
Yes it's the same - though I was looking at the speaker wire colors versus actual pin numbers. But should be the same. I cut an RCA cable in half, split the wires, peeled back the outer wiring (negative) and the center wire (positive) and tapped into the speaker wire accordingly converting them to RCA ends to connect into my aftermarket amp. Worked great no issues.
Wonder if a combination of my #3 option with @maxw’s #4 would be to use a normal relay with the ground trigger from pin8 (which I suspect that is what the complicated Cayenne camera does and needs a lot of power for that whole mechanism).
This is a relay I found on Amazon https://a.co/d/5h607WM and its configuration with a ground trigger below.
Also, does anybody know any good source for constant 12V (accessory) power in proximity to the passenger rear light?
Last edited by nikandriko; 03-16-2023 at 07:26 PM.
With respect to those who are trying to accommodate an aftermarket amp (non-bose car) I'm wondering if the pin out from an older PCCM unit is the same for the PCCM+ unit:
If they are the same then I could bypass these wires into RCA females to accommodate the line in to the amp. It's frustrating that on aliexpress you can buy the same radio, except for sd card nav , with dedicated RCA amp outs and this unit does not have that option. I suppose porsche felt this is an option for porsches that have not had their audio systems violated .. ?
We provide accessory power while use pin8 for a triggered ground so that we get the 0.5sec delay and the camera is not always ON. Farley told me that lots of car accessories work with triggered ground vs. triggered 12V.
Would love to hear what you guys think is best.
I know via @maxw that pin5 NC pushes 3.3V constantly - if this could be connected to camPWR
and then pin8 (camera -12v max 200ma) be connected as camGND (switched ground)
then this would be easy + simple. the camera would only turn on (have its ground circuit closed) when it the car is in reverse only.
Also, does anybody know any good source for constant 12V (accessory) power in proximity to the passenger rear light?
Make sure to fish a Dc extension cable (for the camera) when fishing the rca video cable - now you can wire both camera power + gnd from the radio area. Much more options
Make sure to fish a Dc extension cable (for the camera) when fishing the rca video cable - now you can wire both camera power + gnd from the radio area. Much more options
Could also place a relay behind the pccm and only run the 12V device power through the existing cable. Effectively, this will convert the triggered ground to triggered 12V.
One way I am thinking of using the switched ground on pin8 is provide accessory power to the camera in the back and use the switched ground as ground for it. It should get the benefit of the 0.5sec delay and then the circuit will be open.
Confirmed and tested this worked - great call out @nikandriko ! Solves a mystery here. Forget what I said about a 10 second relay (will delete those prior comments), it's not needed. So here is what I tested/confirmed:
Pin 8 - indeed is switched ground and where you should connect the ground for the camera. For powering the camera, I connected to switched 12v from the fuse box. The PCCM+ clearly has an internal 10 second delay power off on this switched ground, so no error message with the camera when shifting out of reverse (keeps power going for 10 seconds).
Pin 5 - was not able to power the camera off of this. When the PCCM+ is turned on but ignition off on the car, it registers 3.3v. As soon as you turn on the ignition it immediately goes to 0v. I tested putting in reverse as well (triggering pin 6) and it stayed at 0v. As soon as ignition is turned off, it goes back to 3.3v and stays there until PCCM+ is turned off and a period of time goes by for the car to go to sleep (after dash lights off showing mileage, etc.). Not sure what the purpose of this is - but is what I measured testing it.
03-16-2023, 11:54 AM
