HEADLIGHT AUTO LEVELING SYSTEM
id091800010900
Outline
• Automatically adjusts the headlight optical axis in response to changes in load and passenger conditions to prevent blinding of oncoming vehicles from headlight glare and to assure a range of visibility.
Function
• The headlight auto leveling system is controlled by the AFS control module.
• The AFS control module also controls the adaptive front lighting system (AFS) which changes the optical axis to the direction in which the vehicle is travelling according to the steering wheel operation and vehicle speed while the headlights are turned on. (See
ADAPTIVE FRONT LIGHTING SYSTEM (AFS).)
Optical axis adjustment function
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• If the ignition is switched ON (engine on or off) and there is a vehicle height change when the headlights LO are illuminated, the AFS control module automatically adjusts the headlight optical axis.
• The AFS control module controls the optical axis adjustment function based on the following CAN signals.
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CAN signal sending module
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Signal name
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PCM
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Vehicle speed signal
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Instrument cluster
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Ignition switch status signal
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Front body control module (FBCM)
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Headlight illumination status signal
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Structural View
System Wiring Diagram
Operation
Headlights switched from off to on while vehicle is stopped
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Operation condition
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• Ignition switch ON (engine off or on)
• Vehicle speed is 0 km/h {0 mph}.
• At point in time headlights were switched from off to on
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Operation
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1. When the AFS control module receives a headlight on signal, it calculates the target headlight optical axis based on the average vehicle inclination amount calculated in the 1 s just before receiving the signal.
2. The AFS control module outputs the target headlight optical axis signal to the headlight leveling actuator.
3. The headlight leveling actuator calculates the motor drive amount based on the target optical axis signal from the AFS control module and drives the motor until the headlights reach the target optical axis level.
Headlights switched from off to on while vehicle is stopped then vehicle inclination amount changed
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Operation condition
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• Ignition switch ON (engine off or on)
• Vehicle speed is 0 km/h {0 mph}.
• Headlight is on.
• At point where vehicle inclination amount exceeds threshold value
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Operation
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1. The AFS control module monitors the vehicle inclination amount for 3 s after the vehicle inclination amount exceeds the threshold value.
2. If the vehicle inclination amount during the 3 s period does not exceed the threshold value, the AFS control module calculates the target headlight optical axis based on the average vehicle inclination amount in the final 1 s period.
3. The AFS control module outputs the target headlight optical axis signal to the headlight leveling actuator.
4. The headlight leveling actuator calculates the motor drive amount based on the target optical axis signal from the AFS control module and drives the motor until the headlights reach the target optical axis level.
Headlights switched from off to on while vehicle is driven
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Operation condition
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• Ignition switch ON (engine on)
• Vehicle is driven at a constant speed of 30 km/h {19 mph} or more.
• At point in time headlights were switched from off to on
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Operation
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1. When the vehicle condition is changed from the stopped condition to the driving condition, the AFS control module records the average vehicle inclination amount calculated in the final 1 s period of the vehicle stopped condition.
2. When the AFS control module receives a headlight on signal, it calculates the target optical axis based on the recorded vehicle inclination amount.
3. The AFS control module outputs the target headlight optical axis signal to the headlight leveling actuator.
4. The headlight leveling actuator calculates the motor drive amount based on the target optical axis signal from the AFS control module and drives the motor until the headlights reach the target optical axis level.
Vehicle condition changed from stop to driving, then vehicle inclination amount changed
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Note
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• Optical axis control during vehicle travel is performed one time during one period of travel.
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Operation condition
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• Ignition switch ON (engine off or on)
• Vehicle is driven at a constant speed of 30 km/h {19 mph} or more.
• Headlight is on.
• At point where vehicle inclination amount exceeds threshold value
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Operation
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1. The AFS control module monitors the vehicle inclination amount for 3 s from the point that the vehicle inclination amount exceeds the threshold value after the vehicle condition is changed from the stopped condition to the driving condition.
2. If the vehicle inclination amount does not exceed the threshold value during the 3 s period, the AFS control module calculates the target optical axis based on the average vehicle inclination amount during the 3 s period.
3. The AFS control module outputs the target headlight optical axis signal to the headlight leveling actuator.
4. The headlight leveling actuator calculates the motor drive amount based on the target optical axis signal from the AFS control module and drives the motor until the headlights reach the target optical axis level.
Vehicle inclination amount changed while vehicle is driven
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Note
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• Optical axis control during vehicle travel is performed one time during one period of travel.
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Operation condition
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• Ignition switch ON (engine on)
• Vehicle is driven at a constant speed of 30 km/h {19 mph} or more.
• Headlight is on.
• At point where vehicle inclination amount exceeds threshold value
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Operation
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1. The AFS control module monitors the vehicle inclination amount for 3 s from the point that the vehicle inclination amount exceeds the threshold value while the vehicle is driven.
2. If the vehicle inclination amount does not exceed the threshold value during the 3 s period, the AFS control module calculates the target optical axis based on the average vehicle inclination amount during the 3 s period.
3. The AFS control module outputs the target headlight optical axis signal to the headlight leveling actuator.
4. The headlight leveling actuator calculates the motor drive amount based on the target optical axis signal from the AFS control module and drives the motor until the headlights reach the target optical axis level.
