Depress the button on the seat belt buckle. If the belt does not fully retract, pull it out and check for kinks or twists. Then make sure it remains untwisted as it retracts.

NOTE
If a belt does not fully retract, inspect it for kinks and twists. If it is still not retracting properly, have it inspected at an Authorized Mazda Dealer.
Fastening the Seat Belt
Front Shoulder Belt AdjusterMazda 6 Owners Manual: Dtc table
DTCs are common for present and past malfunction diagnosis.
Note
When DTCs not shown in the DTC table are displayed, replace
the SAS unit.
If the air bag system warning light does not illuminate or
remains illuminated when the ignition switch is turned to ON position,
i ...
Mazda 6 Owners Manual: Rear bumper removal/installation
1. Disconnect the negative battery cable.
2. Remove the rear combination light.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Rear Bumper Removal Note
Pull the rear bumper ends (wheel arch) outward to disengage with the bumper
slider.
Cautio ...