The ornamental design for an air vent module, as shown and described.
FIG. 1 is a front top perspective view of an air vent module showing my new design.
FIG. 2 is a rear bottom perspective view thereof.
FIG. 3 is a top plan view thereof.
FIG. 4 is a bottom plan view thereof.
FIG. 5 is a right side elevation view thereof.
FIG. 6 is a left side elevation view thereof.
FIG. 7 is a front elevation view thereof; and,
FIG. 8 is a rear elevation view thereof.
The dash-dash lines demark the boundary of disclaimed portions that form no part of the claimed design. No claim is made to portions that are not shown.