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 ProcedureAir Intake Actuator Inspection [Full Auto Air Conditioner]
1. Connect battery positive voltage to air intake actuator terminal B (or C),
connect terminal C (or B) to ground, and then verify that the air intake actuator
operates as shown in the table.
If the operation condition is not normal, replace the air intake actuator.
...
Vehicle 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 ...
Vanity Mirror Illumination Inspection
1. Disconnect the negative battery cable..
2. Remove the sunvisor..
3. Verify that the continuity between the vanity mirror illumination terminals
is as indicated in the table.
If not as indicated in the table, inspect the bulb. If there is no malfunction,
replace the sunvisor.
...