Mazda 6 Service Manual: No.16 judder upon torque converter clutch (tcc) operation

No.15 engine flares up or slips when accelerating vehicle

No.17 excessive shift shock from n to d or n to r position/range

Other materials:

Mazda 6 Service Manual: Ignition switch inspection
1. Disconnect the negative battery cable. 2. Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION) 3. Disconnect the ignition switch connectors. 4. Inspect for continuity between the ignition switch terminals using an ohmmeter. If not as specified, replace the ignition switch. ...

Mazda 6 Service Manual: Installation of radio system
If a radio system is installed improperly or if a high-powered type is used, the CIS and other systems may be affected. When the vehicle is to be equipped with a radio, observe the following precautions: Install the antenna at the farthest point from control modules. Install the antenna fe ...