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06-29-2026LAST POST
itrocks4u wrote
Hello,

Ive gone through this thread quite extensively.

For backup camera, I keep seeing the option for GreenYi. Most recommend it from Ali Express and says to pick option D. I dont see option D on the site anymore. Can anyone confirm the camera model which may ne option D?

1. CVBS-AHD720P-170deg
2. AHD1080P-175deg

Thanks.

https://www.aliexpress.us/item/2251832698786430.html
1. CVBS-AHD720P-170deg

the Mr12volt and CIC cannot support anything higher than 720p.
Vostec wrote
Found the solution: You will have to connect the iPhone to the car several times.
Eventually, a device named "CarPlay Device" will appear in the settings list, this is the Mr12Volt interface.
Can you please elaborate on this? Are you using an IPhone 17 PM? I just spoke with Mr12V this morning for like the 10th time any they have informed me there is No fix as of yet. They know there is a problem, but they do not know how to resolve it. Even the new IOS26.1 is No Help.
RUG8RB8 wrote
Can you please elaborate on this? Are you using an IPhone 17 PM? I just spoke with Mr12V this morning for like the 10th time any they have informed me there is No fix as of yet. They know there is a problem, but they do not know how to resolve it. Even the new IOS26.1 is No Help.
Ugh. My car is now in storage for the winter, but was hoping to hear 26.1 solved the issue. I'm also using a 17PM... connects fine from a cold start, but drops after a few minutes.
Seeing all this low-key scares me to install myself. I love CarPlay with my 330i and it’s such a convenient tool, but I don’t wanna spend the extra labor money to have someone install a CarPlay system in the M3. But still, a part of me says to just jump the gun and go for it. Thanks for sharing!
Is anyone have issues with getting Mr12Volt to display backup sensor window when in reverse? I've got a 6 speed, and when in reverse I can hear the beeping when objects are nearby but the screen that shows how far/close you are doesn't show up. My understanding is it would go out of the CarPlay menu to show that screen and then come back into CarPlay once the car is out of reverse. Thanks in advance!
RUG8RB8 wrote
Can you please elaborate on this? Are you using an IPhone 17 PM? I just spoke with Mr12V this morning for like the 10th time any they have informed me there is No fix as of yet. They know there is a problem, but they do not know how to resolve it. Even the new IOS26.1 is No Help.
I am using an iPhone 14 Pro on iOS 26.0.1

Maybe it just takes a couple of times disconnecting and reconnecting or restarting the iPhone.

After several days, the Mr12Volt device showed up in the CarPlay settings like it was always there.
pngo12 wrote
Is anyone have issues with getting Mr12Volt to display backup sensor window when in reverse? I've got a 6 speed, and when in reverse I can hear the beeping when objects are nearby but the screen that shows how far/close you are doesn't show up. My understanding is it would go out of the CarPlay menu to show that screen and then come back into CarPlay once the car is out of reverse. Thanks in advance!
Did you tap into the reverse light power to activate the signal?
Thumbie wrote
Did you tap into the reverse light power to activate the signal?
I had no idea you were supposed to do that, I just followed along the mr12Volt video. I don't see where you would tap that signal into the reverse though. Most things were just plug n play into the CIC stuff
pngo12 wrote
I had no idea you were supposed to do that, I just followed along the mr12Volt video. I don't see where you would tap that signal into the reverse though. Most things were just plug n play into the CIC stuff
No, that's incorrect, that would be for a reverse camera being fitted. If you are only wanting the OEM PDC showing then go into the Mr12volt "Settings" menu, down to "Car Setting", first option is "Reverse Camera", click on "OE Camera", this will then display the OE PDC screen when in reverse. :thumbsup:
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DavesZed wrote
No, that's incorrect, that would be for a reverse camera being fitted. If you are only wanting the OEM PDC showing then go into the Mr12volt "Settings" menu, down to "Car Setting", first option is "Reverse Camera", click on "OE Camera", this will then display the OE PDC screen when in reverse. :thumbsup:
^ what he said.

I misread your question, my b.
Hello,

So I got the Green Yi camera from ali express. BUT which DIY guide do I follow, especially to wire in the car?

Please help
I have some Very Good News! Mr12V has now released the IP17 firmware patch! I am on vacation but have downloaded and installed the Porsche version last night and it works great! Happy to has a fully functioning system again! I will do my M3 next week.
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I successfully installed the iOS26 iP17 fix. The issue is now the iPhone does not see the bluetooth Mr12Volt to make the first time connection. In the iPhone bluetooth settings there are no devices to connect to.

And to make matters worse, the USB connection no longer connects my iPhone to the Mr12Volt.
smass wrote
I successfully installed the iOS26 iP17 fix. The issue is now the iPhone does not see the bluetooth Mr12Volt to make the first time connection. In the iPhone bluetooth settings there are no devices to connect to.

And to make matters worse, the USB connection no longer connects my iPhone to the Mr12Volt.
need to unpair your phone and then turn off Bluetooth turn it back on then re-pair.
GORDON.M3 wrote
need to unpair your phone and then turn off Bluetooth turn it back on then re-pair.
Thanks but I have not been paired in many weeks. I was using the USB cable until a fix came out. I reset network setting on the iPhone. Reset to factory on the mr12volt. Rebooted both. Nothing allows me to see the Mr12volt bluetooth as something I can connect to.

Sometimes the Mr12volt's bluetooth device name on the bluetooth connection screen is Car_Audio_0341. Other times just Car_Audio. There are no connected BT devices currently.
Well now I have bricked it. It won't even turn on. I found out why the USB was not working. In the Factory Mode there is a Phone Link Settings area. It was set to Wireless. I then selected USB and Wireless. But when I selected Apply and then restarted, it has not turned back on since.

What are some ways to reset back to factory? thanks
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Just finished the update. Before you begin, highly suggest you remove your phone's CarPlay pairing. Be sure to also go to Settings > Bluetooth click the (i) next to your Mr12Volt device and click "Forget This Device". If you didn't do this and already updated, you can do it now.

Do the full update procedure as documented on the update site.

Once the Mr12Volt finishes its final reboot (after your remove the USB stick), now pair it again.

Go to your phone, go to Settings > Bluetooth, and you'll see the Mr12Volt device waiting to pair. Click on it, Pair, and your car should reconnect to CarPlay again.
smass wrote
Well now I have bricked it. It won't even turn on. I found out why the USB was not working. In the Factory Mode there is a Phone Link Settings area. It was set to Wireless. I then selected USB and Wireless. But when I selected Apply and then restarted, it has not turned back on since.

What are some ways to reset back to factory? thanks
I was able to unbrick the MR12volt. I used an older micro SD flash flash (3.5). That did not roll back the firmware but did shock the system into boothing. I then applied the USB iPhone 17 update again just to be safe. USB works now but bluetooth is still not presenting itself to my phone as a device to connect to.
itrocks4u wrote
Hello,

So I got the Green Yi camera from ali express. BUT which DIY guide do I follow, especially to wire in the car?

Please help
Here is the wiring diagram for mr12volt. All the wires should be labeled from the mr12volt unit.

Also this is how to connect the camera. Photo not mine, from 20 pages back. You need to run the long cable it comes with through the rubber boot in the trunk, all the way to the front of the car where the mr12volt unit is.

Is your car a manual transmission? If so, there is an extra step. The wire labeled reverse light 12V needs to be connected to the reverse light positive.

I forget what I did now, but I want to say i used the red wire (in the trunk lid) and did a three way connection to the red wire, to the camera, and the positive reverse light wire (but don't quote me on this). I wish I took a picture.

But if you have DCT I think you just connect the red wire to the camera (in the trunk) and the Rear Cam 12v from the unit.
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DavesZed wrote
No, that's incorrect, that would be for a reverse camera being fitted. If you are only wanting the OEM PDC showing then go into the Mr12volt "Settings" menu, down to "Car Setting", first option is "Reverse Camera", click on "OE Camera", this will then display the OE PDC screen when in reverse. :thumbsup:
Appreciate this! Checked out the settings and it was on "OE Camera". Tried a few different ones but no dice. Might have to reset the 12volt or something. I'll update the thread if I come across a solution
smass wrote
I was able to unbrick the MR12volt. I used an older micro SD flash flash (3.5). That did not roll back the firmware but did shock the system into boothing. I then applied the USB iPhone 17 update again just to be safe. USB works now but bluetooth is still not presenting itself to my phone as a device to connect to.
Thanks for that info, my box (version 2, black box) is currently bricked, just sticks on the boot screen following the first part of the new update, wont go any further. Although I've contacted Mr12volt, they are very slow in responding and we're not getting anywhere, so I'll give this a try and see what happens :thumbsup: