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 AdjusterAudio Set (Type B)
NOTE
The explanation of functions described in this manual may differ from the actual
operation, and the shapes of screens and buttons and the letters and characters
displayed
may also differ from the actual appearance.
Additionally, depending on future software updates, the content may succ ...
Body Control Module (Bcm) Inspection
1. Remove the following parts:
a. Front scuff plate (LH).
b. Front side trim (LH).
c. Upper panel.
d. Shift knob (MTX).
e. Selector lever knob (ATX).
f. Shift panel.
g. Side wall.
h. Console.
2. Set the hood release lever out of the way..
3. Remove the lower panel. (driver-side). ...
How the SRS Air Bags Work
Your Mazda is equipped with the following types of SRS air bags. SRS air bags
are
designed to work together with the seat belts to help to reduce injuries during
an accident.
The SRS air bags are designed to provide further protection for passengers in
addition to the
seat belt functions. ...