Ironhide has just enough respect for what he's seen of the more comprehensible aspects of the human species to remember his passenger, and to decide that he really does owe the sprite something better than the possibility of going into darkness. Not that he expects to get killed in battle, per se, but if it should happen, Bob deserves a better fate than that. It's not his fault he got stuck in the Cybertronian's systems.
So, when no one's looking, Ironhide shifts into alt mode and finds himself the nearest available publicly accessible computer that seems like its code should be reasonably compatible with Bob's own. It's a vending machine of some kind, but it's got a network connection. Once he's negotiated a link with the computer- okay, 'negotiated' is too nice a word, more like 'demanded and slagging well got'- he reactivates the stasis sector Bob's been stored in.
"Wake up, Bob. We're on Earth."
His avatar's changed. It's still his bot mode, but... well, Ironhide does like to show off. It wasn't all that hard to change it to match his new, part-Earth-aesthetic appearance.