[otrs] "Pending auto close+" and "Pending auto close-"

Hi all, I checked the admin guide, and found that auto close+ means Successful, and auto close- means unsuccessful. But I tried both, and the timer expires, and still the ticket is not closed. Is there a configuration setting, such as a minimum timer or so? I had the timer set to 10 minutes in the future. Thanks and Best Regards, Muhammad El-Sergani.