To remove the fuel-filler cap, turn it counterclockwise.
Attach the removed cap to the inner side of the fuel lid.
To close the fuel-filler cap, turn it clockwise until a click is heard.

CAUTION
(U.S.A. and Canada)
If the check fuel cap warning light illuminates, the fuel-filler cap may not be properly installed. If the warning light illuminates, park your vehicle safely off the right-of-way, remove the fuel-filler cap and reinstall it correctly.
After the cap has been correctly installed, the fuel cap warning light may continue to illuminate until a number of driving cycles have been completed. A drive cycle consists of starting the engine (after four or more hours with the engine off) and driving the vehicle on city and highway roads.
Continuing to drive with the check fuel cap warning light illuminated could cause the check engine light to illuminate as well.
Fuel-Filler Lid
Steering WheelMazda 6 Owners Manual: Idle air control (iac) valve inspection
Note
Perform the following inspection only when directed.
Operation Test
Carry out the Idle Air Control Inspection. (See Idle Air Control System
Inspection.)
If not as specified, perform the further inspection for the IAC valve.
Resistance Inspection
1. Disconnect the negative batt ...
Mazda 6 Owners Manual: Door switch removal/installation
Front
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
3. Install in the reverse order of removal.
Rear
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
3. Install in the reverse order of removal. ...