LIGHTING SYSTEM

FUNCTION OF MAIN COMPONENTS

Component		Function
Main Body ECU (Multiplex Network Body ECU)		Receives the light control signal and transmits a signal to the semiconductor PWR integration ECU.
Headlight Dimmer Switch Assembly Light Control Switch		Outputs a light control signal and transmits it to the main body ECU (multiplex network body ECU).
Headlight Assembly	Discharge Headlight Bulb	The discharge bulb light shines ahead over a broader area and further forward, increasing the area visible to the driver.
Headlight Assembly	Headlight Light Control ECU Sub-assembly LH/RH	Transforms battery voltage to a high voltage of up to 30000 V and applies it to the discharge bulbs in order to illuminate them.
Semiconductor PWR Integration ECU		Supplies power to the headlight light control ECU sub-assembly LH/RH.

FAIL-SAFE

The headlight light control ECU sub-assembly LH/RH stops illuminating the HID headlights when any of the following abnormalities are detected.

Condition	Content
Open in output side circuit	Stops illuminating the headlights. Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
Short between output terminals	Stops illuminating the headlights. Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
Leak between output terminal and body ground	Stops illuminating the headlights. Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
Excessively low output voltage	Stops illuminating the headlights when the output voltage becomes too low (31 +/- 3 V or less). Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
Excessively high output voltage	Stops illuminating the headlights when the output voltage becomes too high (69 +/- 4 V or more). Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
Excessively high input voltage	Stops illuminating the headlights when the input voltage becomes too high (20 +/- 3 V or more). Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).
Low input voltage	Stops illuminating the headlights when the input voltage becomes too low (below 6 V). Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).