Finally, I needed to set up my rear view camera! I actually had already installed a multimedia interface (MMI) system from modmynav 2 years ago for the CCC. I bought it because it was cheaper than the bimmertech kit, but modmynav just mailed me a bimmertech kit. Go figure.
So I ended up upgrading my MMI because I have a manual transmission without PDC. If you A. have an automatic transmission (with or without PDC) or if B. you have a manual transmission with PDC,
you should consider going the $3AG emulator route instead! (Looks much more OEM.) Cars with manual w/o PDC can't use the $3AG emulator though. If you have auto trans and/or PDC, you *might* still want to go the MMI route if you want phone screen mirroring or emulated carplay; keep reading below.
I bought this MMI interface. (They run occasional sales, I got it for $180.) I'm using it just for rear-view camera, but if you want smartphone mirroring then you can
add this. The same website has a version with an HDMI input as well; the smartphone mirroring device can use either RCA or HDMI. I went with the non-HDMI version specifically because the HDMI version is controlled with the CIC controller and I have a CCC controller; the RCA version includes an IR remote so the CIC controller isn't used. There are many interfaces available, I think there is even one that emulates Apple Carplay. (car solutions doesn't sell the carplay one, you will have to go to aliexpress)
Here is the BimmerTech video on installing the camera and an MMI. (Done by Bryan of Kies Motorsports!) As you can see, it's literally the same unit (QPI-BM09). The main difference is that bimmertech took the rear view power cable and pre-spliced it for you. Also, in an e92, I found it impossible to fish a wire from under the glovebox to behind the screen; maybe I couldn't find the right place to start. I found that once I pulled the headunit frame out, I could fish from behind the headunit up to the screen on the right, however.
I already had a camera, but if you need one, both Amazon and eBay have them for $15-30. Just search for "BMW e90 rear view camera handle" (you want the trunk handle version, it's much nicer... the license plate light version is cheaper but not appreciably so). See if you can find one with the micro-connector like in Bryan's video.
You can shove the box wherever it is convenient - I put it behind the AC panel as there is a perfect spot there right above the CIC. It's snug, and will not rattle.
The installation instructions on the car solutions website (storefront linked above) is actually pretty clear. There are 7 connections.
LVDS-in: The original CIC to CID cable goes from the CIC to this port.
LCD-out: The new LCD cable in the box goes from this port to the CID.
Power: The power cable has a 7 pin plug but only 4 wires coming out of it (12V+, ground, CAN high, CAN low, pin 5 blank, pin 6 blank, pin 7 blank). You do not need to tap any wires, it just plugs into your CID and your CID power cable plugs into it.
If you have a manual without PDC like me, you will need to add a wire to pin 7 to activate the rear camera. See below.
Rear: You attach the rear camera power cable here. It comes with a red/black cable. If your camera had a long red/black cable, you would splice together here. If it only has a long video cable with red tails at both ends, you would attach red to red here for 12V+, and black would be spliced to ground (pin 2 of the power cable). Likewise, in the trunk you would have to splice the red tail to the red cable coming from the camera. The black cable from the camera would be spliced to a ground connection there (probably the right tail light harness either in the trunk lid or above the battery, depending on where you connect your camera).
AV In/Out: There is a whole harness of RCA cables here, but I only connected one - the video cable from the rear camera.
Mode cable: This connects to a switch. I connected it but don't have routine need for it. It hides behind the glovebox.
IR cable: This connects to the IR receiver for the remote. I connected it but only used it for initial configuration. It also hides behind the glovebox.
DIP switches: Set 1-4 as you like per the manual. 5, 6, and 8 should be off. 7 should be on. If you change the switches, you will need to disconnect power to reboot it so the new settings take effect.
Making the pin 7 rear camera activation wire for cars with manual transmission without PDC: You will need an automotive relay
like this one. This is an inducible switch sends 12V+ to the reverse trigger wire when the triggering circuit (reverse light) is closed. Tap pin 30 to 12V+ (pin 1 of the power cable), pin 85 to ground (pin 2 of the power cable), and pin 87 to the reverse trigger wire (your new pin 7 of the power cable). Pin 86 goes to either 1. the trunk of the car and your passenger reverse light 12V+ (black and blue cable at the end of the connector) or 2. pin 47 of the X14261 connector of your FRM module (the other end of the tail light connector). Pin 87a isn't used. How this works - when your tail light comes on, pin 86 (tail light) is connected to pin 85 (ground). The relay then connects pin 30 and pin 87, supplying 12V+ to the trigger.
You'll notice the kit doesn't come with a wire for pin 7 though... I already had such a wire from my CCC days. But you can sacrifice a wire from the unused 10-pin android navigation box connector (unless of course you bought an android navigation box that connects to this via that wire). You can sacrifice one of the wires from your unused sat radio prep in the trunk since sat radio is now in the front. You can grab one from pretty much any BMW connector found in the junkyard. Or
make one yourself!
Finally, when you power it up and go into the system menu, be sure to set REAR TYPE to LAMP if you're using pin 7 and a relay, or to CAN if you are using the signal coming from your PDC / auto trans.
And that's the end of my crazy build log!