Translation:The van that you drove is broken down.
Duo, you need to drink more coffee, since it seems that you have been sleeping through your English lessons. You can say that a van has broken down (an event), or that it is broken (a condition), but AFAIK, unless it has been disassembled, you can't say that it is broken down. (Maybe there are some regions where people do say that, in which case you might accept it, but there's absolutely no reason to reject "is broken".)
In addition to what Bryce53261 posted, I'll add that "broken-down" is very commonly used as an adjective. (Sometimes I hear "broke-down", but I'd avoid that, myself.)
For example, "Among the items for sale is a broken-down F-150 pickup truck".
Generally speaking, I can imagine saying (say) "My car is broken right now", but that's not what I would normally say.
I've no idea what a broken van is, unless it is one that is in pieces. If it could not be driven because of some type of failure then it "broke down" in the past. If it has still not been fixed then it is "still broken down". The addition of "still" helps the English understanding. The military use "unserviceable" for something that is not currently working. This might be a better translation of the French, but would not be used in general English conversation. "Kaput" is also a fairly common slang term!
The question is whether the French sentence given can reasonably mean "broke down" as opposed to "is broken down". When Duo rejected my answer, I went to Google translate, and they gave me exactly the same English sentence I had entered.
Admittedly, Google Translate isn't always reliable; hence my asking here.
I don't disagree at all about the difference you mention in English; my question is whether the French sentence can express either one of those.
Thanks for replying, anyway.
OK. I think the answer to your question is probably "no". To say "broke down" (which is in the past) the French would "la camionnette est tombée en panne". I think this is because "en panne" on its own is not a verb but rather the state of the van, whereas "to break down" is a verb, the equivalent of which is "tomber en panne" (probably meaning literally to fall into a state of not working). However I would be happy to bow to superior knowledge.