Because the antenna system is equipped with a capacitor, the continuity cannot be checked. Therefore proceed the following simple inspection.
Turn the AM radio on.
Tune to the frequency that there is no broadcast and you will hear a buzzing sound.
Turn a work light on and shake it around the antenna rod. (around 10—20 mm {0.40—0.78 in})
CAUTION:
Use a fluorescent light type for the inspection. Accurate diagnostic cannot be done with a different type of light.

If a whirring sound from the speaker synchronized to the work light movement is confirmed, the antenna system is normal.
Coil Antenna Removal/Installation
Entertainment Personalization Features Setting ProcedureVehicle Engine Control Unit Reset Procedure
NOTE
This procedure is intended for vehicles with the engine oil flexible
maintenance setting
selected.
After replacing the engine oil, have a repair shop such as an Authorized
Mazda Dealer
perform the initialization (engine oil data resetting) of the recorded value. If
the value
recorded ...
Gracenote Database (Type B)
When a USB device is connected to this unit and the audio is played, the
album name,
artist name, genre and title information are automatically displayed if there is
a match in
the vehicle's database compilation to the music being played. The information
stored in this
device uses database ...
Glass Antenna Inspection
4SD
1. Disconnect the negative battery cable..
2. Disconnect the antenna amplifier connector B..
3. Disconnect the antenna feeder No.3 connector C. (with audio unit (with display)).
4. Inspect the glass antenna for damage visually.
5. Inspect for continuity between the glass antenna termin ...