Lighting System Fail-Safe Chart

Body Electrical. Lexus Gs430, Gs300. Uzs190 Grs190
Lighting. Lexus Gs430, Gs300. Uzs190 Grs190

  1. FAIL-SAFE

Lighting System -- Fail-Safe Chart



FAIL-SAFE

  1. Headlight beam level control ECU
    The headlight beam level control ECU executes the fail-safe actions listed below in accordance with the item that has been detected.

    Item
    		Outline
    Detection of Abnormal Input Voltage
    1. If voltage that is input to headlight beam level control ECU deviates from operating voltage (9 to 16 V), ECU stops illuminating the headlights, and resumes illuminating headlight once the voltage reverts to the operating voltage range
    2. However, if input voltage decreases after headlights have illuminated, headlight will remain illuminated until bulbs are extinguished
    Detection of Abnormal Output (open or short circuit) or Flashing Bulb
    		If abnormal condition (open or short circuit) occurs in voltage that is output by headlight beam level control ECU, or if bulb flashes, ECU stops illuminating headlights and will maintain this state until power is reinstated (by turning headlight control switch from ON or OFF)
    Detection of Bulb Open
    		If bulb is not inserted in its socket, ECU stops generating high voltage until bulb is inserted correctly and power is reinstated (by turning headlight control switch from OFF to ON or turning engine switch from off to on (IG))

  2. Headlight beam level control system
    The headlight beam level control ECU operates in the fail-safe mode if an abnormal condition such as those listed below has been detected, and illuminates the automatic headlight leveling system warning light in the combination meter.

    Item
    		Abnormality Detection Condition
    		Description of Control
    Actuator
    		Open or Short
    		Holds beam at position of actuator when abnormality has been detected
    Height Control Sensor
    		Signal Level Abnormality
    1. Returns beam to actuator's initial set position if abnormality has been detected higher than initial set position
    2. Holds beam at position of actuator when abnormality has been detected, if abnormality has been detected lower than initial set position
    Headlight Beam Level Control ECU
    		When an abnormal processing of the CPU has been detected
    		Holds beam at position of actuator when abnormality has been detected
    Generator Signal
    		When CHG- is low and vehicle speed is 0 km/h (0 mph) or more for 10 seconds
    		Continue light control
    Vehicle Speed Signal
    		When one side is 0 km/h (0 mph) and other side is more than 0 km/h (mph)
    		Continue light control using normal vehicle speed signal