California Code, Probate Code - PROB § 11704

(b)(1) The personal representative may petition the court for authorization to participate, as necessary to assist the court, in the proceeding.  Notice of the hearing on the petition shall be given to the persons identified in Section 11701 in the manner provided in Section 1220.

(2) The court may grant or deny this petition, in whole or in part, on the pleadings, without an evidentiary hearing or further discovery.  A petition filed pursuant to this subdivision may be granted only upon a showing of good cause.  The court shall determine the manner and capacity in which the personal representative may provide assistance in the proceeding.  The court may direct the personal representative to file papers as a party to the proceeding, or to take other specified action, if deemed by the court to be necessary to assist the court.