Short answer. Yes. Article 2116 requires it in plain terms: after the public auction, the pledgee shall promptly advise the pledgor or owner of the result. The creditor cannot sell your pledged item and then stay silent — he owes you prompt notice of how the auction turned out.
What the law says
After the public auction, the pledgee shall promptly advise the pledgor or owner of the result thereof.
Civil Code, Article 2116 — Notice of the Result. Read the full provision →
The duty stated plainly
The article imposes a clear, affirmative duty on the creditor who has sold a pledge. After the public auction, the pledgee shall promptly advise the pledgor or owner of the result thereof. It is not optional or a mere courtesy: the pledgee shall advise, and he must do so promptly. The notice goes to the pledgor, or to the owner of the thing if that is a different person — because the item may have been pledged by someone other than its owner. Having taken and sold another person's property to satisfy a debt, the pledgee is bound to report back on what the sale produced.
Why the pledgor needs to know the result
The requirement exists because the pledgor has a direct and continuing interest in the outcome even after the thing is sold. The sale was conducted for his account: it is his property that was disposed of, and the proceeds are applied to his debt. Whether the auction cleared the debt, left him still owing a balance, or produced money over and above it, all turn on the result. Without notice, the pledgor is left in the dark about whether his obligation is discharged, reduced, or ongoing, and about whether anything is owed back to him. The duty to advise ensures he learns where he stands rather than having to guess or investigate.
What 'promptly' implies and what the notice conveys
The word promptly means the notice cannot be sat on; the pledgor is entitled to be told without undue delay once the auction is over, while the matter is fresh and any further step can still be taken in good time. Although the article speaks only of advising the pledgor of the result, a meaningful notice conveys what he needs to act on: that the sale took place and what it yielded against the debt. A bare or belated word that leaves the pledgor unable to tell whether he is owed a surplus or still owes a balance does not really serve the purpose the article has in mind.
What turns on the result
What makes the result worth prompt telling is the money that follows from it. If the auction brought in more than the debt, the surplus belongs to the pledgor and must come back to him; he cannot claim what he does not know exists. If it brought in less, he needs to know a balance may remain. Either way, the notice is the trigger for sorting out the accounts between the parties. So if your pledged item has been auctioned and you have heard nothing, the pledgee is not entitled to that silence — the law puts on him the duty to advise you promptly of how the sale came out.