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: Foreword
When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to following flowchart. - If a DTC exists, diagnose the applicable DTC inspection. (See DTC TABLE.) - ...

Mazda 6 Service Manual: Electric Parking Brake
The electric parking brake equipment applies the parking brake using an electric motor. When the electric parking brake is applied, the electric parking brake switch indicator light turns on. WARNING Do not drive the vehicle with the electric parking brake applied: If the vehicle is driven ...