It's up to DM fiat. I'd say the creature is under no special compulsion to listen to the translator. If your friend knows the language though, I'd allow them to tell you the specific words to tell the summon. They could even tell you how to say the phrase, "do what he says".
And intelligent summons are still intelligent creatures of their type. If there are no enemies to attack, the summon could be reasoned with by an ally and the ally could use diplomacy to get it to do what they want. A particularly good creature like an archon, might help out someone in trouble without even being asked.
It appears where you designate and acts immediately, on your turn. It attacks your opponents to the best of its ability. If you can communicate with the creature, you can direct it not to attack, to attack particular enemies, or to perform other actions.
Other than the creature's innate behavior, this is all we have to go on about how a summoned creature acts.
------As an aside, this is why I love the Herald Caller so much. Even without standard action casting or minutes per level summons, this ability is just too good.
The herald caller and her summoned monsters can understand each other’s spoken words as if they shared a common language (though this doesn’t give summoned monsters the ability to speak if they normally lack it).
a Traveler's Translator would be an inexpensive option. You would have to get an ally to teach the translator the language you want to be able to communicate in, but after that you should be good to go. Provided of course that you're only summoning one creature at a time. After a certain point it's probably easier just to learn the language or get enchanted with tongues permanently(of course unless you can cast permanency yourself you'd probably have to use something like magic jar to make it work, pending DM discretion of course).
or you could grab a Gold node ioun stone and stick it in a wayfinder. But that only gives you one language per ioun stone.