Diagnostic procedure
Mazda 6 Service Manual: Exterior lighting system
...
Mazda 6 Service Manual: Variable tumble control system (vtcs) shutter valve actuator inspection
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.
If the rod dose not move, replace the intake ...