HIGH BEAM CONTROL (HBC) SYSTEM

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Outline

Caution

•  Under the following conditions the ability of the FSC to detect light-emitting objects decreases, which could result in the system not operating normally and the inability to detect on-coming vehicles or vehicles ahead.

―  Brightness of moonlight in surrounding area

―  Poor visibility due to rain and fog

―  Scratches or soiling on the camera lens or windshield glass

•  Do not rely solely on the HBC system, and perform the appropriate switching operation based on a visual determination of the conditions.

•  If the FSC aiming for the high beam control (HBC) system is not completed, the camera shot angle for the FSC cannot be recorded and the high beam control (HBC) system may not operate. When performing the following servicing, always perform the FSC aiming. Refer to the FSC aiming procedure in the workshop manual.

―  FSC replacement

―  FSC clip replacement

―  Windshield replacement

Function

•  With the light switch in the AUTO and HI position and when the headlights are turned on, the FSC automatically switches to low beams when it recognizes a light-emitting object (on-coming vehicle, vehicle ahead, town and city streets). Refer to FORWARD SENSING CAMERA (FSC)for details on the FSC.

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Setting function for control order of precedence

•  If several light-emitting objects are recognized (on-coming vehicles, vehicles ahead, town/city streets), control is conducted according to the following order of precedence.

1.  Closest on-coming vehicle

2.  Closest vehicle ahead (no on-coming vehicles)

3.  Traveling through towns and cities

System conditions display function

•  The FSC displays system conditions using the HBC indicator light (green), HBC warning light (amber), and TFT LCD display (with TFT LCD display) in the instrument cluster.

Condition		HBC indicator light (green)	HBC warning light (amber)	TFT LCD display
Light switch is in position other than AUTO and high position		Illumination off	Illumination off	No display
Headlights off
While vehicle is stopped
System set to off by personalization
Light switch is in AUTO and high position and headlights turned on		Illumination on	Illumination off	No display
FSC detects camera fogging		Illumination off	Illumination on
FSC detects camera soiling
Malfunction in HBC occurs			Flashes
Malfunction in FSC occurs

Structural view

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System wiring diagram

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Block diagram

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Operation

Low beam switching operation

Operation condition

•  With the light switch in the AUTO and HI position and when the headlights are turned on, the headlights are switched to low beams when any of the following conditions are met:

―  On-coming vehicles, vehicles ahead, town/city streets are recognized.

―  Vehicle speed is 20 km/h {12 mph} or less

1.  When the FSC recognizes a light-emitting object (on-coming vehicles, vehicles ahead, town/city streets) or detects a vehicle speed of 20 km/h {12 mph}, it sends a low beam switching request signal to the front body control module (FBCM).

2.  When the front body control module (FBCM) receives a headlight low beam switching request signal from the forward sensing camera (FSC), it turns the headlight HI relay off.

3.  When the headlight HI relay turns off, energization to the high-beam solenoid is cut and the shade rotates.

4.  When the shade rotates, high beam light is blocked, and only low beam light is illuminated.

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HI beam return operation

Operation condition

•  If the following conditions are met, the headlights are switched to HI beams.

―  If vehicle speed is 30 km/h {19 mph} and on-coming vehicles, vehicles ahead or street lights are not recognized

On-coming vehicles

1.  If a recognized on-coming vehicle moves away from the camera range, the FSC sends a HI beam switching request signal to the front body control module (FBCM).

2.  When the front body control module (FBCM) receives a headlight low beam switching request signal from the forward sensing camera (FSC), it turns the headlight HI relay on.

3.  When the headlight HI relay turns on, the high-beam solenoid is energized and the shade rotates.

4.  When the shade rotates, the blocked high-beam light is illuminated forward, and the headlight switches to high beam.

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Vehicle ahead or town/city streets (street lights)

1.  If a recognized vehicle ahead moves away from the camera range, or town/city streets (street lights) are no longer detected in the camera range, the low beams are maintained for a certain period of time.

2.  If a vehicle ahead or town/city streets (street lights) are not detected for a certain period of time, the FSC sends a HI beam switching request signal to the front body control module (FBCM).

3.  When the front body control module (FBCM) receives a headlight low beam switching request signal from the forward sensing camera (FSC), it turns the headlight HI relay on.

4.  When the headlight HI relay turns on, the high-beam solenoid is energized and the shade rotates.

5.  When the shade rotates, the blocked high-beam light is illuminated forward, and the headlight switches to high beam.

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FSC loses sight of vehicle ahead which is cornering

•  If the FSC loses sight of a recognized vehicle which is cornering, the FSC maintains the low beams until reaching the locus at which the FSC lost sight of it. If the vehicle ahead is not detected at the locus at which the FSC had lost sight of it, the headlights are switched to high beams. If the vehicle ahead is detected, the low beams are maintained.

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FSC suddenly loses sight of light-emitting object (on-coming vehicles, vehicles ahead, town/city streets (street lights))

•  If the FSC suddenly loses sight of a recognized light-emitting object in the camera range, the low beams are maintained for a certain period of time. Depending on whether a light-emitting object is detected or not after the certain period of time has elapsed, the headlights are switched to high beams or the system determines that the low beams are to be maintained.

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Fail-safe

•  If a malfunction is detected in the system, control is inhibited and the headlights are switched to HI beams.