1. Remove the air filter.
2. Inspect the air filter.
Note

Air filter removal/installation
A/c unit removal/installationMazda 6 Service Manual: Canceling Operation of Blind Spot Monitoring (BSM)
The Blind Spot Monitoring (BSM) system can be set to inoperable.
When the Blind Spot Monitoring (BSM) is set to inoperable, the Blind Spot Monitoring
(BSM) and Rear Cross Traffic Alert (RCTA) systems are turned off and the Blind Spot
Monitoring (BSM) OFF indicator light in the instrument cluste ...
Mazda 6 Service Manual: Foreword
Caution
When the engine does not start or stalls and the following DTCs
are not indicated, go to engine symptom troubleshooting.
Note
When the immobilizer system is defective, the engine cannot be
started.
If engine condition is normal but light stays on, inspect for
short circ ...