Mazda CX-3 Owner's Manual page 311

NOTE
The vehicle posture changes depending on the accelerator pedal, brake pedal and
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steering wheel operations, which could make it diffi cult for the system to recognise an
obstruction, or it could facilitate unnecessary detection. In such cases, the Smart City
Brake Support [Reverse] (SCBS R) may or may not operate.
The Smart City Brake Support [Reverse] (SCBS R) system will operate under the
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following conditions.
The engine is running.
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The change lever (manual transaxle vehicle) or the selector lever (automatic
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transaxle vehicle) is in the R (reverse) position.
The vehicle speed is between about 2 to 8 km/h (2 to 4 mph).
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The Smart City Brake Support [Reverse] (SCBS R) is not turned off.
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The DSC is not malfunctioning.
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The Smart City Brake Support [Reverse] (SCBS R) operates using ultrasonic sensors
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(rear) which detect obstructions at the rear by emitting ultrasonic waves and then
receiving the returning waves refl ected off the obstructions.
In the following cases, the ultrasonic sensors (rear) cannot detect obstructions and the
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Smart City Brake Support [Reverse] (SCBS R) may not operate.
The height of the obstruction is low such as low walls or trucks with low loading
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platforms.
The height of the obstruction is high such as trucks with high loading platforms.
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The obstruction is small.
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The obstruction is thin such as a signpost.
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The obstruction is positioned away from the centre of the vehicle.
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The surface of the obstruction is not pointed vertically relative to the vehicle.
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The obstruction is soft such as a hanging curtain or snow stuck to a vehicle.
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The obstruction is shaped irregularly.
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The obstruction is extremely close.
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When Driving
i-ACTIVSENSE
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