as some have mentioned previously, I believe the project manager should be a great problem solver. on any team, each member should be capable of completing tasks on their own. it is when there are conflicts of opinion or challenges that the team members have difficulty solving that the manager shines. while communication is important, the project manager is there to resolve any issues that the team members have that is beyond their set of responsibilities so that the each member can function at their optimal capacity. whether that requires the PM seek assistance from upper management or work directly with the team to resolve any challenges.