1. Remove the air hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
2. Disconnect the vacuum hose from the VTCS shutter valve actuator.

3. Connect a vacuum pump to the VTCS shutter valve actuator.
4. Apply vacuum and verify that the rod moves.

Variable intake-air system (vis) control solenoid valve inspection (l3)
Variable tumble control solenoid valve inspectionMazda 6 Service Manual: Supplemental Restraint System Components
(With Front Passenger Occupant Classification System)
(Without Front Passenger Occupant Classification System)
Driver/Front passenger inflators and air bags
Roll-over sensor (some models), crash sensors, and diagnostic module (SAS
unit).
Seat belt pretensioners
Front air bag sensor ...
Mazda 6 Service Manual: Front drain hose installation
Caution
If the front drain hose is pinched or bent anywhere, the water in the hose
may not discharge and enter the inside of the vehicle. During and after
installation of the trims and the headliner, always make sure there is no
interference with the front drain hose. Fix any problem if found ...