§1. When it is established by law that in order to place acts a superior needs the consent or counsel of some college or group of persons, the college or group must be convoked according to the norm of can. 166 unless, when it concerns seeking counsel only, particular or proper law provides otherwise. For such acts to be valid, however, it is required that the consent of an absolute majority of those present is obtained or that the counsel of all is sought.
§2. When it is established by law that in order to place acts a superior needs the consent or counsel of certain persons as individuals: 1/ if consent is required, the act of a superior who does not seek the consent of those persons or who acts contrary to the opinion of all or any of them is invalid; 2/ if counsel is required, the act of a superior who does not hear those persons is invalid; although not obliged to accept their opinion even if unanimous, a superior is nonetheless not to act contrary to that opinion, especially if unanimous, without a reason which is overriding in the superior’s judgment.
§3. All whose consent or counsel is required are obliged to offer their opinion sincerely and, if the gravity of the affair requires it, to observe secrecy diligently; moreover, the superior can insist upon this obligation.
Source: Code of Canon Law (Vatican.va)