Displays in the following cases:

Stop Vehicle in Safe Place Immediately
Message Indicated in Multi-information DisplayMazda 6 Owners Manual: Disconnection of the negative battery cable
Before beginning any work, turn the ignition switch to LOCK position,
then disconnect the negative battery cable and wait for more than 1 minute
to allow the backup power supply of the SAS unit to deplete its stored
power. Disconnecting the battery cable will delete the memories of the
...
Mazda 6 Owners Manual: Fuel pump unit inspection
Caution
It is normal to hear the fuel pump operating when the ignition
switch is turned to the ON position.
Note
To improve startability, the fuel pump control operates the fuel
pump unit when the ignition switch is turned to the ON position. Due to
this, fuel pressure is rapidly ...