(a)
If the probation officer determines that the minor shall be retained in custody, he shall immediately proceed in accordance with Article 16 (commencing with Section 650) to cause the filing of a petition pursuant to Section 656 with the clerk of the juvenile court who shall set the matter for hearing on the detention calendar. Immediately upon filing the petition with the clerk of the juvenile court, if the minor is alleged to be a person described in Section 601 or 602, the probation officer or the prosecuting attorney, as the case may be, shall serve such minor with a copy of the petition and notify him of the time and place of the detention hearing. The probation officer, or the prosecuting attorney, as the case may be, shall thereupon notify each parent or each guardian of the minor of the time and place of such hearing if the whereabouts of each parent or guardian can be ascertained by due diligence. Such notice may be given orally.
(b)
In such hearing the minor has a privilege against self-incrimination and has a right to confrontation by, and cross-examination of, any person examined by the court as provided in Section 635.