Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners 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 ...
Mazda 6 Owners Manual: Starter removal/installation
Warning
When the battery cables are connected, touching the vehicle body with starter
terminal B will generate sparks. This can cause personal injury, fire, and
damage to the electrical components. Always disconnect the battery negative
cables before performing the following operation.
1. Di ...