Mazda 2013 CX-9 Owner's Manual page 220

Operation Conditions
The system can be used when the ignition is switched ON.
The sensors detect obstructions under the following conditions:
Sensor
Rear Sensor
Rear Corner Sensor
qParking Sensor Warning Beep
The beeper sounds as follows while the system is operating.
Distance between vehicle and obstruction
Rear Sensor
Approx. 150―100 cm (59.0―39.3 in)
Approx. 100―50 cm (39.3―19 in)
Approx. 50―30 cm (19―11 in)
Within approx. 30 cm (11 in)
*1 The speed of the intermittent sound increases as the vehicle approaches the obstruction.
The shift lever is in reverse (R).
The shift lever is in reverse (R), and the vehicle speed is about 10 km/h (6 mph) or less.
Condition
Rear Corner Sensor
Approx. 150―100 cm (59.0―39.3 in)
Approx. 100―50 cm (39.3―19 in)
Approx. 50―30 cm (19―11 in)
Within approx. 30 cm (11 in)
Driving Your Mazda
Starting and Driving
Beeper sound
Slow intermittent sound
Medium intermittent
sound
Fast intermittent sound
Continuous sound
*1
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