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 AdjusterBattery Inspection [Mzr 2.0, Mzr 2.5]
WARNING:
Since battery acid is toxic, be careful when handling the battery.
Since battery acid is highly corrosive, be careful not to allow it to contact
clothing or the vehicle.
In case battery acid contacts skin, eyes, or clothing, flush it immediately
with running wa ...
Theft Deterrent System Clearing Freeze Frame Data
1. Connect the M-MDS (IDS) to the DLC–2.
2. After the vehicle is identified, select the following items from the initialization
screen of the IDS.
Select “Body”.
Select "Burglar Service Functions".
3. Then, select the following item from the screen menu.
...
Theft Deterrent System Reading Freeze Frame Data
1. Connect the M-MDS (IDS) to the DLC–2.
2. After the vehicle is identified, select the following items from the initialization
screen of the IDS.
Select “Body”.
Select "Burglar Service Functions".
3. Then, select the following item from the screen menu.
...