Must I abandon my engineering studies, which include a philosophy course, based on a vow I made, knowing that my family rejects this and that other study opportunities are limited?

The definition of philosophy and its ruling have been previously explained. Studying aspects of philosophy related to creed, fundamentals of religion, and unseen matters, based purely on rational thought and an atheistic perspective, is not permissible unless one is fortified with Islamic knowledge and intends to refute its falsehoods.

Accordingly, if this is the type of philosophy being taught to you, and you possess Islamic knowledge to refute doubts, or if the subject is not important, or can be bypassed, then there is no harm in continuing your studies. However, if it is compulsory and you do not possess sufficient Islamic knowledge to refute its doubts, then it is not permissible to continue studying it, due to the danger it poses to your religion, and there is no obedience to your parents in this regard.

Given that the school specializes in training engineers and philosophy is not a core subject in it, you are not obligated to leave it. Rather, you should compensate for the philosophy course or bypass it. Your statement, "If this study will tempt me away from my religion, I will abandon it," is not considered a vow due to its lack of a formula of commitment.