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: Radar Sensors (Rear) (Some models)
Your vehicle is equipped with radar sensors (rear). The following systems also use the radar sensors (rear). Blind Spot Monitoring system (BSM) Rear Cross Traffic Alert (RCTA) The radar sensors (rear) function by detecting the radio waves reflected off a vehicle approaching from the rea ...

Mazda 6 Service Manual: Road test
Warning When performing a road test, be aware of other vehicles, people, impediments, etc. to avoid an accident. Note When the legal speed limit must be exceeded, use a chassis dynamomenter instead of performing a road test. Road Test Preparation 1. Inspect the engine coolant le ...