What is your ethical obligation in the matter?

Suppose you are a member of a team working on a computer-controlled crash avoidance system for automobiles. You think the system has a flaw that could endanger people. The project manager does not seem concerned and expects to announce completion of the project soon. Do you have an ethical obligation to do something?
Please help with any thoughts that you have on this scenario, thank you.

If a person has undeniable proof that a product is being marketed that exposes the public to death or seriously injury, they have an ethical obligation to bring it to the attention of management, go over their head to the top of the company if it's ignored and go public if it becomes necessary.

A mid-level manager may be foolish enough to ignore such a problem but any top level managers that have the slightest understanding of the legal and financial ramifications of putting such a product on the market should applaud the act.