(a) Subject to Section 1286.4, the court shall vacate the award if the court determines any of the following:
(1) The award was procured by corruption, fraud or other undue means.
(2) There was corruption in any of the arbitrators.
(3) The rights of the party were substantially prejudiced by misconduct of a neutral arbitrator.
(4) The arbitrators exceeded their powers and the award cannot be corrected without affecting the merits of the decision upon the controversy submitted.
(5) The rights of the party were substantially prejudiced by the refusal of the arbitrators to postpone the hearing upon sufficient cause being shown therefor or by the refusal of the arbitrators to hear evidence material to the controversy or by other conduct of the arbitrators contrary to the provisions of this title.
(6) An arbitrator making the award either: (A) failed to disclose within the time required for disclosure a ground for disqualification of which the arbitrator was then aware; or (B) was subject to disqualification upon grounds specified in Section 1281.91 but failed upon receipt of timely demand to disqualify himself or herself as required by that provision. However, this subdivision does not apply to arbitration proceedings conducted under a collective bargaining agreement between employers and employees or between their respective representatives.
(b) Petitions to vacate an arbitration award pursuant to Section 1285 are subject to the provisions of Section 128.7.