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 AdjusterUp Switch Inspection [FS5 A EL]
1. Perform the following procedures.
a. Remove the battery cover..
b. Disconnect the negative battery cable.
c. Remove the console..
d. Disconnect the selector lever component connector.
2. Inspect the continuity between the selector lever component terminals B and
H.
If ...
Antenna Feeder No.5 Inspection
1. Disconnect the negative battery cable..
2. Remove the following parts:
a. Front scuff plate (RH).
b. Front side trim (RH).
c. Rear seat cushion.
d. Rear scuff plate (RH).
e. Tire house trim (RH).
3. Disconnect the antenna feeder No.4.
4. Disconnect the antenna feeder No.3.
...
Electric Variable Valve Timing Motor/Driver Removal/Installation [Skyactiv G
2.0]
WARNING:
A hot engine can cause severe burns. Turn off the engine and wait until it
is cool before servicing.
CAUTION:
Applying excessive force (force of 100 N {10.2 kgf, 22.5 lbf} or more) to
the electric variable valve timing motor/driver may cause a malfunction. When
...