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: Camera and Sensors
Forward Sensing Camera (FSC)
The Forward Sensing Camera (FSC) detects lane indications and recognizes headlights,
taillights and city lights during nighttime driving. In addition, it also detects
the vehicle ahead, pedestrians, or obstructions. The following systems also use
the Forward Sensi ...
Mazda 6 Owners Manual: Diagnostic trouble code number inspection
1. Remove the glove compartment.
2. Short the A/C check connector to the GND terminal using a jumper wire.
3. Shine a 60 W incandescent light from a height of approximately
100 mm {3.9 in} onto the solar radiation sensor.
Note
When incandescent light does not shine on the solar radiatio ...