SKYACTIV-G 2.0, SKYACTIV-G 2.5, SKYACTIV-G 2.5T

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

Perform the "Fuel Line Safety Procedure" referring to the "BEFORE SERVICE PRECAUTION".
(See BEFORE SERVICE PRECAUTION [SKYACTIV-G (VIN L (US))] .) (See BEFORE SERVICE PRECAUTION [SKYACTIV-G (VIN M (US))] .)
If the fuel gauge level indicates 8/16 or more, refer to the "FUEL DRAINING PROCEDURE" and drain the fuel.
(See FUEL DRAINING PROCEDURE [SKYACTIV-G (VIN L (US))] .) (See FUEL DRAINING PROCEDURE [SKYACTIV-G (VIN M (US))] .)
Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
Remove the fuel gauge sender unit (main). (See FUEL GAUGE SENDER UNIT REMOVAL/INSTALLATION (US) .)

Verify that the resistance at fuel gauge sender unit terminals F and C is as follows according to the height of the float.

Resistance when float is in the highest position

18.5-21.5 ohms
Resistance when float is in the lowest position

197-203 ohms

Courtesy of MAZDA MOTORS CORP.

If the resistance is not within the specification, replace the fuel gauge sender unit. (See FUEL GAUGE SENDER UNIT REMOVAL/INSTALLATION (US) .)