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 AdjusterDriver Side Air Bag Module Removal/Installation [Standard Deployment Control
System]
WARNING:
Handling the air bag module improperly can accidentally deploy the air bag
module, which may seriously injure you. Read the air bag system service warnings
and cautions before handling the air bag module..
1. Switch the ignition to off.
2. Disconnect the negative batte ...
Cooling System Cap Inspection [Mzr 2.0, Mzr 2.5]
WARNING:
Never remove the cooling system cap or loosen the radiator drain plug while
the engine is running, or when the engine and radiator are hot. Scalding engine
coolant and steam may shoot out and cause serious injury. It may also damage
the engine and cooling system.
Tu ...
Check Valve Inspection [Skyactiv G 2.0]
Airflow Inspection
1. Remove the vacuum hose..
2. Blow air into the vacuum hose using your mouth from the vacuum pump side and
verify that the air flows to the intake manifold side, then blow air from the intake
manifold side and verify that the air does not flow to the vacuum pump side.
...