Have you actually done anything promotion-worthy? Stayed late for a few days to get that project finished by the deadline? Taken extra time to mentor more junior colleagues? Introduced initiatives to improve the organization, such as researching new tools to help do your job better/cheaper? Or do you feel that you could help the organization better if you were in a senior position, maybe with your excellent system design/architecture skills, or your great ability to manage other developers and manage projects? Or do you just punch the clock from 9 to 5, and are looking for more money?
You have to give this person a reason to give you a promotion. Think of it this way: if this manager has to justify the promotion of you instead of someone else to their manager, what would you want them to say?