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 AdjusterMazda 6 Owners Manual: Close Proximity Warning
If your vehicle rapidly closes in on the vehicle ahead because the vehicle applies
the brakes suddenly while you are traveling in headway control, the warning sound
activates and the brake warning is indicated in the display. Always verify the safety
of the surrounding area and depress the bra ...
Mazda 6 Owners Manual: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...