On a modular course you must have passed all 14 exams to sit the CPL skills test. Although you can start a course before you have all the passes any responsible school will discourage you from doing too much of the 25 hour course until you have them under your belt.
Best of luck!
(May I ask which you have yet to pass? I teach Gen Nav and Flight planning, and occasionally some P of F, M & B and Radio Nav).