Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Fuel Gauge (Without Multiinformation Display)
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the low fuel warning light illuminates or the fuel level is very low, refuel
as soon as possible.
Refer to Warning Lights.
NOTE
...
Mazda 6 Owners Manual: Indicators
Manual shift mode indication
In manual shift mode, the “M” of the shift position indication in the instrument
panel illuminates.
Gear position indication
The numeral for the selected gear illuminates.
NOTE
If the gears cannot be shifted down when driving at higher speeds, the
gear ...