REAR CROSS TRAFFIC ALERT (RCTA) SYSTEM

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Outline

•  The rear cross traffic alert (RCTA) system detects vehicles approaching from behind using radar and alerts the driver of the presence of an approaching vehicle.

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Structural View

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Functions

Rear cross traffic alert (RCTA) function

•  The rear cross traffic alert (RCTA) function starts detecting approaching vehicles when the selector lever is in the reverse position. The rear side radar sensor warns the driver when it detects an approaching vehicle passing over the alert line shown in the figure within 3.5 sec.

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•  When the rear side radar sensor detects an approaching vehicle, it warns the driver by flashing the blind spot monitoring (BSM) warning light and activating the blind spot monitoring (BSM) warning buzzer.

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System check

•  When the ignition is switched ON (engine off or on), the system checks the conditions for approx. 3 sec. During the system check, the blind spot monitoring (BSM) warning light turns on, and then turns off when the system check is finished. If a system malfunction is found, the i-ACTIVSENSE Warning Lamp remains turned on.

System conditions display

•  The rear side radar sensor (RH) displays the system conditions using the multi-information display and the center display.

System condition		i-ACTIVSENSE status symbol	i-ACTIVSENSE OFF symbol	Blind spot monitoring (BSM) warning lights	Blind spot monitoring (BSM) warning buzzer	Multi-information display	Active driving display	Center display
Right after ignition is switched ON (engine off or on) (System check)		On (Approx. 3 sec)	Off	On (Approx. 3 sec)	Off	No display	No display	No display
Vehicle is driven in reverse	No approaching vehicle which will pass over alert line within 3.5 seconds		Off	Off	Off	No display	No display	No display
	Detected approaching vehicle which will pass over alert line of left side within 3.5 seconds		Off	On	On	No display	No display
	Detected approaching vehicle which will pass over alert line of right side within 3.5 seconds		Off	On	On	No display	No display
	Detected approaching vehicle which will pass over alert line of both sides within 3.5 seconds		Off	On	On	No display	No display
Rear cross traffic alert (RCTA) OFF (non-operational)	System is OFF (non-operational)	Off		Off	Off	No display	No display	No display
Blind spot monitoring (BSM) system malfunction occurred			Off	Off	Off		No display	Warning display

System wiring diagram

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Operation

Warning

•  The rear cross traffic alert (RCTA) system assists the driver in confirming the rear side of the vehicle when backing up. Because of the various restrictions in the system operations, a warning may not occur or it may be delayed even if there is a vehicle at the vehicle rear side. Do not rely completely on the system and always take responsibility as the driver in confirming the area behind the vehicle.

Caution

•  The system may operate under the following conditions even if a vehicle is not approaching.

―  An object that reflects the radio waves of the radar such as a parked vehicle, guardrail, or wall is directly next to your vehicle.

―  A vehicle approaching from the near left and right side of your vehicle slows down.

―  A vehicle approaching from the rear left and right side of your vehicle makes a right or left turn directly in front of your vehicle.

―  A vehicle overtakes your vehicle while it is stopped.

―  Your vehicle is in an area where strong radio waves or electrical noise may occur such as near a television tower or power plant.

•  In the following cases, the i-ACTIVSENSE warning indication/warning light turns on and operation of the system is stopped. If the i-ACTIVSENSE warning indication/warning light remains illuminated, have the vehicle inspected at an Authorized Mazda Dealer as soon as possible.

―  Some problem with the system including the Blind Spot Monitoring (BSM) warning indicator lights has occurred.

―  A large deviation in the installation position of a rear side radar sensor on the vehicle has occurred.

―  There is a large accumulation of snow or ice on the rear bumper near a rear side radar sensor.

―  Driving on snow-covered roads for long periods.

―  The temperature near the radar sensors becomes extremely hot due to driving for long periods on slopes during the summer.

―  The battery voltage has decreased.

•  Under the following conditions, the rear side radar sensor connot detect approaching vehicles or it might be difficult to detect them, and the system may not operate normally.

―  The vehicle speed when reversing is about 15 km/h {9 mph} or faster.

―  The rear side radar sensor detection area is obstructed by a nearby wall or parked vehicle. (Reverse the vehicle to a position where the radar sensor detection area is no longer obstructed.)

Rear cross traffic alert (RCTA) operation

•  When all of the following conditions are met, the rear cross traffic alert (RCTA) function goes on standby.

Preconditions

―  Rear cross traffic alert (RCTA) system is operating

―  Rear cross traffic alert (RCTA) system is normal

―  Selector lever R position signal is received

•  The warning is activated if the following condition is met.

Operation condition

―  An approaching vehicle is detected which will pass over the alert line within 3.5 sec.

•  If any of the following conditions is met, the rear cross traffic alert (RCTA) function stops.

Stop conditions

―  Rear cross traffic alert (RCTA) system is stopped

―  Rear cross traffic alert (RCTA) system has a malfunction

―  Selector lever R position signal is not received

If an approaching vehicle is on the left side

1.  When the preconditions are met, the rear side radar sensor emits electromagnetic wave and starts detecting approaching vehicles.

2.  When the rear side radar sensor (LH) detects an approaching vehicle, it sends (1) the object information to the rear side radar sensor (RH).

3.  If the rear side radar sensor (RH) determines the approaching vehicle while reversing, it sends (2) a RCTA signal to the door-electrical supply unit (driver’s side), door-electrical supply unit (passenger’s side) and connectivity master unit (CMU) via the body control module (BCM).

4.  Based on the RCTA signal (2), the body control module (BCM) outputs the warning sound signal (3) to the Notification and Warning Speaker (Rear) and the Notification and Warning Speaker (Rear) sounds a warning.

5.  Based on the RCTA signal (2), the connectivity master unit (CMU) displays the warning indication (3) on the center display.

6.  Based on the RCTA signal (2), the door-electrical supply unit (driver’s side) and door-electrical supply unit (passenger’s side) flashes (3) the blind spot monitoring (BSM) warning light (LH) and blind spot monitoring (BSM) warning light (RH).

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If an approaching vehicle is on the right side

1.  When the preconditions are met, the rear side radar sensor emits electromagnetic wave and starts detecting approaching vehicles.

2.  If the rear side radar sensor (RH) determines an approaching vehicle while reversing, it sends (1) a RCTA signal to the door-electrical supply unit (driver’s side), door-electrical supply unit (passenger’s side) and the connectivity master unit (CMU) via the body control module (BCM).

3.  Based on the RCTA signal (1), the body control module (BCM) outputs the warning sound signal (2) to the Notification and Warning Speaker (Rear) and the Notification and Warning Speaker (Rear) sounds a warning.

4.  Based on the RCTA signal (1), the connectivity master unit (CMU) displays the warning indication (2) on the center display.

5.  Based on the RCTA signal (1), the door-electrical supply unit (driver’s side) and door-electrical supply unit (passenger’s side) flashes (2) the blind spot monitoring (BSM) warning light (LH) and blind spot monitoring (BSM) warning light (RH).

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