1. Disconnect the back-up light switch connector.
2. Inspect for continuity between the back-up light switch terminals using an ohmmeter.
Mazda 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: Interior Equipment (View A)
1 - Door-lock knob 2 - Lighting control 3 - Turn and lane-change signal
4 - Wiper and washer lever 5 - Tire pressure monitoring system set switch 6
- DSC OFF switch 7 - Lane-keep Assist System (LAS) & Lane Departure Warning System
(LDWS) OFF switch 8 - Outside mirror switch 9 - Door-lock ...