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: Headlights
Turn the headlight switch to turn the headlights and other exterior lights on or off. When the lights are turned on, the lights-on indicator light in the instrument cluster turns on. NOTE If the light switch is left on, the lights will automatically switch off approximately 30 seconds ...

Mazda 6 Service Manual: Clutch master cylinder disassembly/assembly
1. Disassemble in the order indicated in the table. 2. Assemble in the reverse order of disassembly. Snap Ring Disassembly/Assembly Note Hold the piston down using a cloth-wrapped pin punch. If disassembling, remove the snap ring; if assembling, install it. ...