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: Gate operator/Canadian Programming
Canadian radio-frequency laws require transmitter signals to “time-out” (or quit) after several seconds of transmission — which may not be long enough for HomeLink to pick up the signal during programming. Similar to this Canadian law, some U.S. gate operators are designed to “time-out ...

Mazda 6 Service Manual: After repair procedure
Caution After repairing a malfunction, perform this procedure to verify that the malfunction has been corrected. When this procedure is carried out, be sure to drive the vehicle at lawful speed and pay attention to the other vehicles. 1. Connect the WDS or equivalent to the DLC-2. 2. Turn th ...