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 AdjusterTheft 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.
...
General Procedures (Brake)
Wheel and Tire Installation
1. When installing the wheels and tires, tighten the wheel nuts in a criss-cross
pattern to the following tightening torque.
Tightening torque
88—118 N·m {9.0—12 Kgf·m, 65—87 ft·lbf}
Brake Lines Disconnection
1. If any brake line has been disconnec ...
Climate Control Unit Removal/Installation [Full Auto Air Conditioner]
1. Disconnect the negative battery cable..
2. Remove the following parts:
a. Upper panel.
b. Shift lever knob (MTX).
c. Selector lever knob (ATX).
d. Shift panel.
e. Side wall.
f. Console.
g. Center panel.
h. Audio unit.
3. Remove in the order indicated in the table.
...