[smass]

I have retrofitted CIC with dash into both of my E90. The 325i gets its screen and controller can bus from the factory connections. The 330i gets its screen and controller can bus from the back of the quadlock. I also have an E70 that has a CCC to CIC retrofit.

Last weekend I removed a working aliexpress carplay box from my E70 and put it into my 330i. The carplay hooks into the power and bus for the i-drive controller. Once I turned on the ignition, I immediately noticed the dash start to flash. The fuel gauge was bouncing back and forth from full to empty, the i-drive screen had a nasty error message and even the odometer went blank and had the dot. This is classic bus issues that I have had during other retrofits I have done.

First I unhooked the screen can bus wires from the quadlock and moved them to the correct locations of the junction box. This alone solved 80% of the errors. I then reviewed wiring diagrams and while the controller uses the same bus wirring as the quadlock, it does not hook to the quadlock. The junction point is under the middle of the console. I then disconnected the controller can bus from the quadlock and hooked it to the can bus wires that run next to the parking brake. It now has a short 9" run to the controller. That fixed the remaining issues.

Looking back, the 330i had been haveing emulator issues which I was blaming on ebay emulators. Most likely, these were caused by the bus wiring. Next I will install another carplay in my 325i and I plan to correct the controller can bus wiring at that time. So if you are doing this retrofit, do yourself a favor and follow the exact factory wiring for the can bus.

[PichaDis11]

Can-bus wiring can be finicky. These junctions (connections) should be separate even if on the same leg; specially for CAN filtering systems.