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

Air filter removal/installation
A/c unit removal/installationMazda 6 Service Manual: Excessive Speed Warning
If the vehicle speed exceeds the speed limit sign displayed on the active driving
display, the warning sound is activated and the area around the speed limit sign
displayed on the active driving display flashes 3 times in amber, and if the vehicle
speed continues to exceed the displayed speed ...
Mazda 6 Service Manual: Front door lock actuator inspection
Door Lock Actuator
1. Disconnect the front door lock actuator connector.
2. Apply battery positive voltage to the front door lock actuator terminals
and inspect the operation of the front door lock actuator.
If not as specified, replace the front door lock actuator.
With double locking ...