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: Indicators
Manual shift mode indication In manual shift mode, the “M” of the shift position indication in the instrument panel illuminates. Gear position indication The numeral for the selected gear illuminates. NOTE If the gears cannot be shifted down when driving at higher speeds, the gear ...

Mazda 6 Service Manual: Immobilizer system reprogram procedure
Note When an error occurs during the reprogram procedures, except when the PCM is replaced, repeat the procedure from Step 1. If you still cannot reprogram, confirm how many keys can start the engine. Then, perform the key replacement or addition reprogram procedure according to the val ...