Fuel Gauge Sender Unit Inspection

Disconnect the negative battery cable.
Remove the rear seat cushion. (See REAR SEAT CUSHION REMOVAL/INSTALLATION .)
Remove the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI 3.7 V6] .)
Move the float to the topmost and bottommost positions, and verify that the resistance between terminals C and E of the fuel gauge sender unit and the position of the float are as shown in the illustration.

Fig 1: Moving Float To Topmost And Bottommost Positions

Courtesy of MAZDA MOTORS CORP.

If they are not as shown in the illustration, replace the fuel gauge sender unit.