Headlight Leveling System Description - Control/Function

Basic Control/Function 

With the vehicle in the ON mode and headlights ON, the headlight leveling control unit calculates the output voltage to the leveling motor based on the input values of the current vehicle angle, the vehicle angle average value* and the vehicle speed signal. It then activates the leveling motor when the corresponding control conditions are met.

NOTICE: 

* The vehicle angle average value means: The average value over 1 second for the vehicle angle detected 0.6 seconds earlier by the headlight leveling sensor, detected 10 times in intervals of 0.1 seconds.

Control at the Time of Start 

Leveling control output is made when all of the following conditions are satisfied.

• 1.6 seconds or more have passed since input of the engine start/stop switch ON signal.
• The headlights are set to ON.

Control While Stopped 

Leveling control output is made when all of the following conditions are satisfied.

• The vehicle is in the ON mode.
• The headlights are set to ON.
• 1.6 seconds or more have passed since the vehicle has stopped.
• The vehicle angle average value has changed by 0.2 deg. or more to the upper/lower side in regard to the current leveling control angle.

Control While Running 

Leveling control output is made when all of the following conditions remain satisfied uninterrupted for 25 seconds, and the headlight leveling control unit has registered that the vehicle angle is stable; it then performs a leveling control output.

• The vehicle is in the ON mode.
• The headlights are set to ON.
• The change of the vehicle angle is 3 deg. or less.
• The vehicle speed change is 2 mph (3 km/h) or less.
• The vehicle angle average value has changed by 0.2 deg. or more to the upper/lower side in relation to the current leveling control angle.
• The vehicle speed is within the range from 13 to 155 mph (21 to 249 km/h).