If you agree with Descartes that you can be sure of your own conscious, which is one leap of faith, and that it's more likely that the other entities you interact with are a result of evolution just as you, instead of a figment of your imagination (or someone else's), which is yet another leap, you're good to go. And that is the way most of us interpret the human experience.
Inquiring about the consciousness of an artificial entity requires a third leap, since it doesn't share our biological evolution. And it's probably a larger one, as we don't fully understand how we evolved it or what it actually is, really, that we're trying to replicate.
As we do not understand our own consciousness and how it functions (or whether or not it functions in me the way it does in you, if it exists at all - anywhere), we cannot compare a replication of that system to ourselves except as a black box. When seen as a black box, a philosophical zombie and a sapient individual are identical.
A black box is something we don't have access to its inner workings. We can probe and inquire the working brain. It's just really hard and we've been working at it for a few decades only (dissecting a dead brain before powerful microscopes gives you very little insight).
Unless you share the Zen-like opinion that a brain can't understand itself, which I don't, and seems like an issue of faith as well and a dead end.