Mazda 6 Service Manual: No.4 abs or tcs*1 operates frequently/tcs does not work correctly*1: dsc system function contains traction control function, dsc indicator light goes on and off while dsc operates

No.3 there is a malfunction in the system even though abs warning light, brake system warning light, dsc indicator light and tcs-off light do not illuminate

No.5 dsc*2 operates frequently/dsc does not work correctly*2: dsc indicator light goes on and off while dsc operates

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: 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. ...