Can I cross from the USA to Mexico through the CBX?

With plane ticket Yes

CBX can be used only with your plane ticket and buying the pass either simple or round. They do not sell you the CBX pass without your air ticket.

Sii CBX is in San Diego CA ..

Can I use the cbx with just a reservation key?

Someone to help me I will cross from San Diego to Tijuana ... my question is if I can cross with my IFE or I need the Mexican passport