1. Verify that there is no continuity between antenna feeder terminals A and B using an ohmmeter.

2. Inspect for continuity between the antenna feeder terminals using an ohmmeter.

Front antenna feeder inspectionMazda 6 Service Manual: General procedures
PRECAUTION (SUSPENSION)
Wheels and Tires Removal/Installation
When a wheel is installed, tighten it to 88-118 N·m {9.0-12.0 kgf·m,
65.0-87.0 ft·lbf}.
Suspension Links Removal/Installation
Tighten any part of the suspension that uses rubber bushings only after the
vehicle has been lowered ...
Mazda 6 Service Manual: No.5 tcs off light does not illuminate with ignition switch on
Diagnostic procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure co ...