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 AdjusterOwner Maintenance Precautions
The owner or a qualified service technician should make these vehicle
inspections at the
indicated intervals to ensure safe and dependable operation.
Bring any problem to the attention of an Authorized Mazda Dealer or qualified
service
technician as soon as possible.
When Refueling
Bra ...
Mass Air Flow (MAF) Sensor/Intake Air Temperature (Iat) Sensor No.1 Removal/Installation
[Skyactiv G 2.0]
CAUTION:
Be careful not to hit the sensor element or allow foreign matter to get on
it during sensor removal/installation. If the sensor element is hit or foreign
matter gets on it, an error may occur in the sensor output signal resulting
in deterioration in the engine control.
...
Variable Valve Timing Actuator Removal/Installation [Mzr 2.3 Disi Turbo]
WARNING:
Fuel vapor is hazardous. It can very easily ignite, causing serious injury
and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious
injuries or death and damage. Fuel can also irritate skin ...