Pioneer AVH-4200NEX - no video with 2008 OEM backup camera, RP4-MZ11, AX-MAZCAM-6V

Iristyle

Member
Hi -

I've swapped out my OEM Mazda head unit on my 2008 GT (Bose w/ NAV but no entertainment system) with a Pioneer AVH-4200NEX.

The setup is working nearly perfectly:

* Steering wheel controls appear to be fully operational
* Output through the RCA jacks to the Bose is working just fine
* Accessory output 12V is measured on the red wire, and head unit turns on with ignition in accessory

I'm having some problems with the Reverse + output from the PAC interface though. The head unit is configured for "ground" with the backup camera, so that it will switch mode upon reverse (with it set to "battery" it goes into camera mode when I'm driving regularly) - going from memory, hopefully I didn't mix those up (I have tried both settings). However, it is not working reliably. Sometimes while driving the camera display will come on, and sometimes when shifting into reverse it doesn't come on (typically when I start the car it works). After switching from reverse to drive, the camera screen does not turn off. In addition to the detection of reverse / forward behaving intermittently, the camera itself is not showing any video - the screen is always black. I'm using the AX-MAZCAM-6V harness (https://axxessinterfaces.com/product/AX-MAZCAM-6V) to power / connect to the OEM wiring. I have wired the 12V accessory power (red wire) from the RP4-MZ11 into the 12V -> 6V stepdown, and have measured 6V on the harness pin of the AX-MAZCAM-6. From what I can see the camera should be powered properly. I have not yet tested for 6V at the camera in the rear hatch door itself.


Has anyone seen a situation where the Reverse + output is not behaving correctly like this and / or there is absolutely no video?

I have seen a similar report elsewhere on the Mazda forums, but it's not making a lot of sense to me:

https://www.mazdas247.com/forum/sho...arket-Stereo&p=6286784&viewfull=1#post6286784

"Also note, I found it took the PAC a while to 'learn' the car's LAN signals. The orange illumination and green reverse signals did not work right away. I thought my wiring was bad, or the PAC was faulty. But they did finally start to work after some time. Weird."


A few other notes about my install:

* I have wired the Green Reverse Output (+) from the PAC interface connector to the purple / white wire on the Pioneer harness - Pioneer manual states: "Of the two lead wires connected to the back lamp, connect the one in which the voltage changes when the gear shift
is in the REVERSE (R) position. This connection enables the product to sense whether the car is moving forwards or backwards."

* I have a MicroBypass installed (https://www.amazon.com/dp/ (commissions earned)) that is connected to the parking brake, instead of using anything from the PAC. I am not using the RP4s purple/ white VSS output OR red/white P.B. output
* All of the connections have been soldered / heat-shrinked, so I'm quite certain there are no loose connections
* The PAC unit is on latest firmware 5.4.4
* I replaced my OEM Sirius with the sxv300 and re-ran an antenna from the trunk because I couldn't find a DIN adapter and didn't feel like making my own (mentioning only as I removed the Mazda switching box which allows Sirius + AUX to function)


Any help here would be appreciated. Thanks!
 

Iristyle

Member
For the sake of others, I was able to get to the bottom of my 2 issues:


* The camera was not showing a signal because the positive / negative video signal wires were reversed in the AX-MAZCAM-6V camera harness. I took apart my trunk and tested the connection at the connector to the camera. I measured the 6V power as correct with my multimeter. I rigged up a different RCA based video source and found that the video was backwards.

It wasn't pretty, but it did the trick:

Euaq40ESgtXiunoleg9YQNd3FC_2LxdZ1_epijrZkfzYxwOcv8WmgNx8AXgEKl_BpjtiAe3uy0eVTkzoL9fJIUOF_P9mmjmWTthClWqjzx-0FyaG3Wx0hKlfMya_2oG-PJWnF_Lw2Uk=w1920-h1440-no


To fix, I used the tabs in the AX-MAZCAM-6V connector to release the + / - video pins, and switched them. The connector ended up looking like the following after fixing it:

gpDoxpKuLOtGp50avs5ihzm6fxi7qwozMKAG-UB7a-H-BXriyBNXfBpfE2jvN7vqbCfw2gxoduNRDJERTjQxMGhpfx_iWcGLv6_g1jeAD6oS9RRWQCF6zspV2C94T5rpvXtUe8XGCX8=w1920-h1440-no


* As for the PAC unit being really flaky in correctly emitting an on / off signal for the car in reverse, the manufacturer stated through email:

I'm sorry to hear that you are having problems with your RP4-MZ11. The issue with the reverse output is not very common but it does happen sometimes. You can try replacing the interface, but you may have the same issue with the new one. If everything else is working, I would keep the one you have and run a wire from the reverse lamp instead of using the reverse output from the interface.

I tore everything up again to be able to run a wire from the rear liftgate door where the tail lights are (which was a real pain), but then did a little searching to see if I can find a better location closer by in the dash somewhere. Sure enough, I found the thread at
https://www.mazdas247.com/forum/sho...kup-Camera-amp-Mirror-Instructions-12v-Backup

That thread contains PDF instructions on how to use the 24 pin connector to the BCM under the driver side kick panel to get 12V of power through the red / yellow striped pin V. I first tested that the information was correct using my multimeter and an old PC CDROM 4 pin connector like
SKCIjo85LyY7us6mZqqzuy6JIeNKjsSstSrD7J5VpsdO2v3XxW49RN0M_6ZyGdcaErqKOhSL6YS9stLYfLEfV-lWwH6YsbAo9RpIYDI5YcQ7xSuOvWn16A7wUAr_P2u018u4_axDFuY=w1920-h1440-no
. That allowed me to safely separate the lines in a way I could test things more easily with the multimeter.

After verifying, I was able to successfully tap in to the red / yellow wire, second from the end of the connector, which is pictured at
i5SaZHERgpQj6P1ObaWxY-T8nrAOtVGMlZv0j5-Jch32BxfHddodRXy_KV-sGUq7gTfPNSjzIZfAlOrY1lAbr-E65KaHsYlnE8-lVg9pvHkbaWVYd4F7fldtarkGfTQtKfnwUWbQpkA=w1614-h2152-no




So after lots of playing around, I finally have everything working!
 
Last edited:
:
SOLD 2002 Protege5; Current 2008 CX-9 Grand Touring
For the sake of others, I was able to get to the bottom of my 2 issues:


* The camera was not showing a signal because the positive / negative video signal wires were reversed in the AX-MAZCAM-6V camera harness. I took apart my trunk and tested the connection at the connector to the camera. I measured the 6V power as correct with my multimeter. I rigged up a different RCA based video source and found that the video was backwards.

It wasn't pretty, but it did the trick:

Euaq40ESgtXiunoleg9YQNd3FC_2LxdZ1_epijrZkfzYxwOcv8WmgNx8AXgEKl_BpjtiAe3uy0eVTkzoL9fJIUOF_P9mmjmWTthClWqjzx-0FyaG3Wx0hKlfMya_2oG-PJWnF_Lw2Uk=w1920-h1440-no


To fix, I used the tabs in the AX-MAZCAM-6V connector to release the + / - video pins, and switched them. The connector ended up looking like the following after fixing it:

gpDoxpKuLOtGp50avs5ihzm6fxi7qwozMKAG-UB7a-H-BXriyBNXfBpfE2jvN7vqbCfw2gxoduNRDJERTjQxMGhpfx_iWcGLv6_g1jeAD6oS9RRWQCF6zspV2C94T5rpvXtUe8XGCX8=w1920-h1440-no


* As for the PAC unit being really flaky in correctly emitting an on / off signal for the car in reverse, the manufacturer stated through email:



I tore everything up again to be able to run a wire from the rear liftgate door where the tail lights are (which was a real pain), but then did a little searching to see if I can find a better location closer by in the dash somewhere. Sure enough, I found the thread at
https://www.mazdas247.com/forum/sho...kup-Camera-amp-Mirror-Instructions-12v-Backup

That thread contains PDF instructions on how to use the 24 pin connector to the BCM under the driver side kick panel to get 12V of power through the red / yellow striped pin V. I first tested that the information was correct using my multimeter and an old PC CDROM 4 pin connector like
SKCIjo85LyY7us6mZqqzuy6JIeNKjsSstSrD7J5VpsdO2v3XxW49RN0M_6ZyGdcaErqKOhSL6YS9stLYfLEfV-lWwH6YsbAo9RpIYDI5YcQ7xSuOvWn16A7wUAr_P2u018u4_axDFuY=w1920-h1440-no
. That allowed me to safely separate the lines in a way I could test things more easily with the multimeter.

After verifying, I was able to successfully tap in to the red / yellow wire, second from the end of the connector, which is pictured at
i5SaZHERgpQj6P1ObaWxY-T8nrAOtVGMlZv0j5-Jch32BxfHddodRXy_KV-sGUq7gTfPNSjzIZfAlOrY1lAbr-E65KaHsYlnE8-lVg9pvHkbaWVYd4F7fldtarkGfTQtKfnwUWbQpkA=w1614-h2152-no




So after lots of playing around, I finally have everything working!

Excellent!!! Dedication, man! Can I see a pic or vid of the new Pioneer in action?
 
@Iristyle I think i had the same problem with you. I tested my reverse wire and it is giving me 10.8 volts. My camera has no signal sometimes wobly video feed. Is it possible that it doesn't have enough power? I am also using ax mazcam 6v
 
This is what’s happening when I put the car in reverse. Either I get a blank screen or a wobly video feed.
 

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Ive tried reversing the polariy (no picture), confirmed 6V (I had to purchase a step down) and all I'm getting are crazy rolling messy pictures with 99% noise. (tried ntsc and pal). I've tried connecting straight to a standalone screen and same issue?? do they have their own standard or something? just noticed - mines the same as the second picture above. bjmigrino - did you ever get it working properly?
 
yep, no signal at all when I changed the polarity
is that what the fix was for yours in the end? wrong polarity was a rolling/messy screen?
 
thanks, just tried again and still the same results. aftermarket camera is fine, factory camera is a mess.

theres 4 wires in the harness, but to be honest I dont get how it would even work in reverse. as far as I can tell it would be video, shield, power, ground. maybe in my case the shield and video are reversed in the harness. Ive rage quit for the day, dash is in pieces LOL. I may have to revert to taking the rear skin off the door and try and mount the after market camera. I really really dont want to go running a new cable from the front to the back though!
 
The camera powers on when in reverse right? So you're ok with the reverse signal. I know! I even bought another mazcam coz i messed the first one. Try interchanging the 4 wires. That's what I did before until i read the solution in the thread. I changed the polarity in my stock reverse camera not in the mazcam. Maybe that will help.
 
wait - you took the skin off in the tailgate and changed the polarity there? I tried taking the skin off (top section first, but I broke a clip or 2). not keen on ripping the whole skin off, but I have no choice anyway - if I end up installing the aftermarket camera
 
awwww man i just realised all this time that you were talking about camera polarity! i thought you meant power which is why i couldnt understand how it still powered up for you. the shield and signal makes sense - im looking at a residual weak shielded signal! will try tomorrow - im confident it will work - cheers!
 
Thanks mate! It worked a treat. I had swapped the polarity on the video feed and heatshrinked it to cover up my really bad soldering. (That was the whole point of why I went a premade harness). now to leave the supplier a review ;)

camera.PNG