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I have an iPhone XR that is cracked all ever the place, and the FaceID stopped working when water got into the phone via cracks. The back is all cracked up too. It also has more gb then my other xr. I have another xr in good condition but less gb. For other reasons I don’t care for explaining about, I want to bring everything from broken phone into my good ones housing. And use my good parts to replace the broken ones. But will the working XR faceID work on the broken hardware?

FaceID components are tied to each specific board so no, you will not be able to restore FaceID by swapping parts unless you swap the corresponding parts like the board with them.