LANE DEPARTURE WARNING SYSTEM (LDWS)

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Outline

•  The Lane Departure Warning System (LDWS) recognizes vehicle lane lines on a road using the forward sensing camera (FSC) installed to the windshield, and if the vehicle departs from its lane unbeknownst to the driver, the system alerts the driver of the lane departure using a warning indication and warning sound.
Warning
•  The lane departure warning system (LDWS) is only a supplementary system for the prevention of a lane departure, however the lane departure warning system (LDWS) functions have limitations. Relying solely on the lane departure warning system (LDWS) and neglecting prudent steering wheel operation could cause an unexpected accident resulting in death or serious injury. Do not rely solely on the lane departure warning system (LDWS). Always make lane corrections using the steering wheel and drive safely.
•  The lane departure warning system (LDWS) may not operate normally under the following conditions:
―  Poor vehicle lane line visibility due to adverse weather (rain, snow, fog)
―  Poor vehicle lane line visibility due to backlight, snow on the road, water puddles, road ruts
―  Poor vehicle lane line visibility due to cracks and fissures in the vehicle lane
―  Vehicle lane lines intersect with complexity due to additions or reductions of travel lanes
―  Vehicle lane marking is not completely erased after road maintenance, two or more lane lines next to each other
―  Vehicle lane lines not recognized due to vehicle ahead
Caution
•  If the forward sensing camera (FSC) aiming is not completed correctly, the forward sensing camera (FSC) cannot record the camera shooting angle and the lane departure warning system (LDWS) may not operate normally. When performing the following servicing, always perform the forward sensing camera (FSC) aiming. In addition, for the forward sensing camera (FSC) aiming procedure, refer to the [FORWARD SENSING CAMERA (FSC) AIMING] in the Workshop Manual.
―  Forward sensing camera (FSC) replacement
―  Windshield replacement

Functions

•  The forward sensing camera (FSC) sets warning-trigger lines based on the vehicle lane lines recognized by the camera, and if the vehicle contacts one of these warning-trigger lines it activates the warning indicator and warning sound. For details on the forward sensing camera (FSC) and warning-trigger lines, refer to [FORWARD SENSING CAMERA (FSC)]. (See FORWARD SENSING CAMERA (FSC).)

Driver operation determination function

•  The forward sensing camera (FSC) determines the following driving operations as the driver's intentions and controls the warning operation.
―  After the turn switch is operated, the vehicle lane is changed within 30 s.
―  The steering wheel is turned at a certain angle or more, and the vehicle lane is changed.
―  The accelerator pedal is depressed a certain amount or more, and the vehicle lane is changed.
―  The brake pedal is depressed a certain amount or more and the vehicle departs from its lane.


System conditions display function

•  The forward sensing camera (FSC) displays the system status using the active driving display and the multi-information display.

LDWS off switch

Condition

Active driving display

Multi-information display

Center display
ON
System is off
No display
No display
OFF
Vehicle lane lines are recognized at a vehicle speed of 60 km/h {37 mph} or more
No display
While warning is triggered
Vehicle speed is 60 km/h {37 mph} or less
No display
Vehicle lane lines are not recognized
Forward sensing camera (FSC) detects camera/windshield fogging
No display
Warning display*1
Forward sensing camera (FSC) detects that the camera/windshield is dirty
No display
Lane departure warning system (LDWS) has a malfunction
No display

*1  :For the warning display content on the center display, refer to the [CENTER DISPLAY]. (See CENTER DISPLAY.)


Structure/Construction


System structure

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System Wiring Diagram

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Block Diagram

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Operation


Operation condition

•  The warning is triggered when all of the following conditions are met:
―  LDWS off switch is off (system on)
―  Vehicle speed signal of approx. 60 km/h {37 mph} or more is received from PCM
―  Vehicle contacts warning-trigger line unbeknownst to driver


Operation

•  The period of time in which the warning is triggered differs by the period of time in which the vehicle is contacting the warning-trigger line.
―  Vehicle contacts warning-trigger line for less than approx. 1 s: Warning triggers for 1 s
―  Vehicle contacts warning-trigger line for approx. 1 s or more: Warning triggers for 1.5 s
•  If the warning is triggered one time, the warning will not trigger again until the vehicle travels within the warning-trigger lines for a period of approx. 2 s.
•  The following three types of warnings can be selected using the personalization feature. (Initial setting is steering wheel vibration. For details on the steering wheel vibration operation, refer to [LANE-KEEP ASSIST SYSTEM]. (See LANE-KEEP ASSIST SYSTEM.))
―  Beep sound output by instrument cluster
―  Rumble strip sound*1 output by tuner and AMP unit (TAU)
―  Steering wheel vibration
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*1  :A rumble strip is a series of grooves in the road pavement surface positioned at specific intervals, and when the vehicle passes over it a rumble sound is produced and an uncomfortable vibration can be felt which alerts the driver that the vehicle is departing from the lane lines. The rumble strip sound is a reproduction of the sound which occurs when a vehicle passes over a rumble strip.
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Rumble strip sound (With active driving display auto flip-up type)
1.  If the forward sensing camera (FSC) determines that the vehicle has contacted a warning-trigger line, it sends (1) a warning sound request signal and a warning indication request signal to the radar unit.
2.  When the radar unit receives the warning sound request signal and the warning indication request signal from the forward sensing camera (FSC), it determines (2) the priority order of the warning based on presence/non-presence of warning request from the mazda radar cruise control with stop & go function (MRCC with stop & go function) or the smart brake support (SBS).
3.  If the radar unit determines that the priority order of the warning sound request signal and the warning indication request signal from the forward sensing camera (FSC) is the highest, it sends (3) the warning indication request signal to the instrument cluster, and the warning sound request signal to the connectivity master unit (CMU).
4.  When the instrument cluster receives the warning indication request signal from the radar unit, it displays (4) the warning indication in the multi-information display/active driving display.
5.  When the connectivity master unit (CMU) receives the warning sound request signal from the radar unit, it sends (5) the warning sound request signal to the tuner and AMP unit (TAU).
6.  When the tuner and AMP unit (TAU) receives the warning sound request signal from the connectivity master unit (CMU), it stops output from either the left or right door speaker and outputs (6) a rumble strip sound.
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Rumble strip sound (With active driving display windshield type)
1.  If the forward sensing camera (FSC) determines that the vehicle has contacted a warning-trigger line, it sends (1) a warning sound request signal and a warning indication request signal to the radar unit.
2.  When the radar unit receives the warning sound request signal and the warning indication signal from the FSC, it determines (2) the priority order of the warning based on presence/non-presence of warning request from the MRCC system or the smart brake support (SBS).
3.  If the radar unit determines that the priority order of the warning sound request signal and the warning indication signal from the FSC is the highest, it sends the warning indication request signal (3) to the instrument cluster, and the warning sound request signal (4) to the connectivity master unit (CMU).
4.   When the instrument cluster receives the warning indication request signal from the radar unit, it displays (5) the warning screen in the multi-information display. In addition, when the active driving display receives the warning indication request signal from the radar unit via the instrument cluster, it displays (5) the warning screen.
5.  When the connectivity master unit (CMU) receives the warning sound request signal from the radar unit, it sends (6) the warning sound request signal to the tuner and amp unit (TAU).
6.  When the tuner and amp unit (TAU) receives the warning sound request signal from the connectivity master unit (CMU), it stops output from either the front left or right door speaker and outputs (7) a rumble strip sound.
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Beep sound
•  For the beep sound operation, refer to the [LANE DEPARTURE WARNING SOUND]. (See LANE DEPARTURE WARNING SOUND.)
Steering wheel vibration
•  For the steering wheel vibration operation, refer to the [LANE-KEEP ASSIST SYSTEM]. (See LANE-KEEP ASSIST SYSTEM.)