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: Replacing Exterior Light Bulbs
Headlights (With LED headlights)
Low/High beam bulbs
The LED bulb cannot be replaced as a single unit because it is an integrated
unit.
The LED bulb has to be replaced with the unit. We recommend an Authorized Mazda
Dealer when the replacement is necessary.
Headlights (With halogen headlight ...
Mazda 6 Service Manual: Locking, Unlocking the Doors
NOTE
The system may not operate if you are too close to the windows or door
handles.
If the key is left in the following areas and you leave the vehicle,
the doors may be locked depending on the radio wave conditions even if the key
is left in the vehicle.
Around the dashboard
...