A. A juvenile shall not participate in a delinquency, incorrigibility or criminal proceeding if the court determines that the juvenile is incompetent to proceed.

B. At any time after the filing of a petition for delinquency or incorrigibility or a petition that seeks to transfer a juvenile to adult court, a party may request in writing or the court on its own motion may order that the juvenile be examined to determine if the juvenile is competent. The request shall state the facts in support of the request for a competency examination. The presence of a mental illness, defect or disability alone is not grounds for finding a juvenile incompetent. The court shall not order a juvenile who is under the jurisdiction of the juvenile court to participate in a treatment program for the restoration of competency unless the court made a prior finding of probable cause pursuant to rule 3(f), rules of procedure for the juvenile court.