Some project manager's don't take the high road consistently. But even for those who do, they may find themselves caught in the middle between a demanding management and a mistrustful, unrealistic client. Therefore, ethics and values are a key attribute, that may be regularly tested, in the project management role.
Project managers who become PMP certified are required to read and agree to the PMP Code of Conduct, which provides the basics that a project manager needs to avoid such as lying, cheating, and stealing. However many of our ethical conflicts are found in the gray areas of choosing between various bad and painful choices.
The links to the right have many great articles about project management ethics, values, and professional conduct concerns. I encourage you to visit them.