Antenna control inspection

Switch the ignition to ACC or ON (engine off or on).
Turn the audio unit power on.
Tune in the radio.
While pressing the POWER/VOLUME button, press the FM/AM/CLOCK button for 0.5 s or more.

Fig 1: POWER/VOLUME Button And FM/AM/CLOCK Button
Courtesy of MAZDA MOTORS CORP.

Inspect according to the following table:

Inspection	Display	Action
Verify the displayed screen. Take action according to the audio.	ANT-ON	Good sound quality	System is normal.
	ANT-ON	Bad sound quality	Inspect the center roof antenna and antenna feeder. (See CENTER ROOF ANTENNA INSPECTION .) (See ANTENNA FEEDER NO. 1 INSPECTION .) (See ANTENNA FEEDER NO. 2 INSPECTION .) (See ANTENNA FEEDER NO. 3 INSPECTION .) If the center roof antenna or antenna feeder is malfunctioning: Replace the malfunctioning part. (See CENTER ROOF ANTENNA REMOVAL/INSTALLATION .) (See ANTENNA FEEDER NO. 1 REMOVAL/INSTALLATION .) (See ANTENNA FEEDER NO. 2 REMOVAL/INSTALLATION .) (See ANTENNA FEEDER NO. 3 REMOVAL/INSTALLATION .) If the center roof antenna and antenna feeder are normal: Replace the audio unit. (See AUDIO UNIT REMOVAL/INSTALLATION .)
	ANT-OFF	Replace the audio unit. (See AUDIO UNIT REMOVAL/INSTALLATION .)

Switch the audio power supply off or switch the ignition off to end the diagnostic assist function.