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: Warning Light and Brake Pad Wear Indicator
Warning Light The warning light turns on when the system has a malfunction. Refer to Warning Indication/Warning Lights Brake Pad Wear Indicator When the disc brake pads become worn, the built-in wear indicators contact the disc plates. This causes a screeching noise to warn that the pads shoul ...

Mazda 6 Service Manual: High-mount brake light removal/installation
4SD In-vehicle-type 1. Disconnect the negative battery cable. 2. Remove in the order indicated in the table. 3. Install in the reverse order of removal. Rear spoiler type 1. Disconnect the negative battery cable. 2. Remove the rear spoiler. (See REAR SPOILER REMOVAL/INSTALLATION) 3. Remo ...