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: Refrigerant pressure switch inspection
1. Install the SST (gas charging set).
2. Disconnect the refrigerant pressure switch connector.
3. Verify the high-pressure side reading of the SST (manifold gauge)
and continuity between the terminals of the refrigerant pressure switch.
If not as specified, replace the refrigerant pressure ...
Mazda 6 Service Manual: Drive belt auto tensioner inspection
1. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
2. Verify that the drive belt auto tensioner moves smoothly in the
operational direction.
Replace the drive belt auto tensioner if necessary.
3. Turn the drive belt auto tensioner pulley by hand and verify that it
rotates smoothly ...