Working as gear expert in starters applications I confirm the answer of diamondjim :IF THE MODULE IS THE SAME, THE PRESSURE ANGLE MUST BE THE SAME
BUT :
the real indispensable and compulsory condition is to have THE SAME BASE PITCH pb= PI*m*cos(alfa)
SO:
you can have different modules AND pressure angle on your pinion and your gear if this condition is respected :
PI*m1*cos(alfa1) = PI*m2*cos(alfa2)
Example :
module 2.11666 (DP12) and pressure angle 12°
module 2.20328 and pressure angle 20°
module 2.1385 and pressure angle 14.5°
these three definitions are used to determine pinions and gears for starter applications and they mesh perfectly together.
The only issue is when you must calculate the gear set : you can only use one module and pressure angle so you must "convert"one of the items from one module to the other keeping the base tangent length constant to determine the profile addendum modification equivalent.