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: Solenoid valve removal/installation
1. Disconnect the negative battery cable. 2. Remove the under cover. 3. Remove the control valve body. (See CONTROL VALVE BODY REMOVAL.) 4. Remove the solenoid valve(s). 5. Apply ATF to a new O-ring and install it on the solenoid valve. 6. Install the solenoid valve in the control valve body. ...

Mazda 6 Service Manual: Lane Departure Warning
If the system determines that the vehicle may deviate from its lane, the lane departure warning (beep sound, rumble sound*1, or steering wheel vibration) is activated and the direction in which the system determines that the vehicle may deviate is indicated in the multi-information display and ...