The verb denotes an anguishing cry of pain. The actual content of the cry can vary: it can include a complaint/lament (1 Samuel 4:13) or a declaration of faith accompanying a call for help (Psalm 142:5). The term does not appear to be a technical term for repentance, even though it is used occasionally for a confession of sin. Rather, “usage suggests it is fundamentally a cry of pain (see especially 2 Samuel 13:19; 2 Samuel 19:4), often accompanied by a lament over one’s condition and/or by a request for divine help. If the context does not specifically indicate that the cry was accompanied by a confession of sin, we should not assume that repentance took place. Consequently, with respect to its usage here in Judges 3:9, all we can say for certain is that oppressed Israel cried out in their pain to the Lord."1
In fact, Judges 10:14 seems to confirm that the element of repentance is lacking. There the Israelites cry out to the Lord (Judges 10:10), and he retorts sarcastically, Go and cry out to the gods whom you have chosen; let them save you in the time of your distress.
2
9 But when the people of Israel cried out to the LORD, the LORD raised up a deliverer for the people of Israel, who saved them, Othniel the son of Kenaz, Caleb’s younger brother.