1. Disconnect the back-up light switch connector.
2. Inspect for continuity between the back-up light switch terminals using an ohmmeter.


Back-up light switch removal/installation
Flasher unit removal/installationMazda 6 Service Manual: Operation
System triggering conditions
The horn sounds intermittently and the hazard warning lights flash for about
30 seconds when the system is triggered by any one of the following:
Unlocking a door with the key, door lock switch, or an inside door-lock
knob.
Forcing open a door, the hood or th ...
Mazda 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 ...