Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

Other materials:

Mazda 6 Service Manual: Inspecting Electrolyte Level
A low level of electrolyte fluid will cause the battery to discharge quickly. Inspect the electrolyte level at least once a week. If it is low, remove the caps and add enough distilled water to bring the level between the upper and lower level (illustration). Do not overfill. Examine the sp ...

Mazda 6 Service Manual: Excessive Speed Warning
If the vehicle speed exceeds the speed limit sign displayed on the active driving display, the warning sound is activated and the area around the speed limit sign displayed on the active driving display flashes 3 times in amber, and if the vehicle speed continues to exceed the displayed speed ...