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Lighting (Diagnostics - Introduction): Overview Lexus RX III

Exterior Lights ~3103 words

SYSTEM DESCRIPTION

  1. AUTOMATIC LIGHT CONTROL SYSTEM When the light control switch is in the AUTO position, the automatic light control system detects ambient light levels and controls the low beam headlights, parking lights, taillights, marker lights and license plate lights.
  2. LIGHT AUTO TURN-OFF SYSTEM The light auto turn-off system is used to prevent the exterior lights from being accidentally left on (low beam headlights, high beam headlights, front fog lights, taillights, parking lights, license plate lights and marker lights). This system has the following functions. Function Outline Driver Side Door-linked Function The exterior lights automatically turn off when all of the following conditions are met: The engine switch is turned from on (IG) to off. The light control switch is in the tail position. The driver side door is opened. Delay Function The exterior lights automatically turn off after 30 seconds when all of the following conditions are met: The engine switch is turned from on (IG) to off. The low beam headlights are on (Light control switch is in the head or AUTO position). All doors are closed after any of the doors are opened. Door Control Transmitter-linked Function The exterior lights turn off immediately when the delay function is active and the following condition is met: The lock button on the key is pushed after all doors are locked.
  3. DAYTIME RUNNING LIGHT SYSTEM The daytime running light system is designed to automatically illuminate the daytime running lights during the daytime to make the vehicle more visible to other vehicles. This system is controlled by the main body ECU (multiplex network body ECU) and power distributor (engine room junction block assembly). The main body ECU (multiplex network body ECU) transmits a turn ON signal to the power distributor (engine room junction block assembly), which illuminates the high beam headlights using duty control. This system is enabled when the following conditions are met: Engine switch on (IG) Engine speed signal input (engine running) Parking brake switch off Light control switch not in the DRL OFF position (w/ DRL OFF switch) Light control switch is in the off (w/o DRL OFF switch), tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system).
  4. AUTOMATIC HIGH BEAM SYSTEM General The automatic high beam system enhances the illumination of the area to the front of the vehicle to improve visibility for the driver. It works by detecting light from the front using the camera built into the inner rear view mirror assembly and switching between the high beams and low beams automatically. Function of Main Components Component Outline Automatic High Beam Sensor (Inner Rear View Mirror Assembly) Determines when to switch between the high beams and low beams after identifying the lights of oncoming vehicles, preceding vehicles and other lights from the picture information of its camera sensor. Then, it sends high beam request signals to the AFS ECU (headlight swivel ECU assembly) via LIN. AFS ECU (Headlight Swivel ECU Assembly) Acts as the gateway between the automatic high beam sensor (inner rear view mirror assembly) which uses LIN communication and the CAN No. 2 bus. In addition, it stores Diagnostic Trouble Codes (DTCs) if an automatic high beam sensor (inner rear view mirror assembly) malfunction occurs. Power Management Control ECU Performs the gateway function between the No. 1 bus and No. 2 bus. Steering Angle Sensor (Spiral Cable Sub-assembly) Outputs the steering angle information to the AFS ECU (headlight swivel ECU assembly). Skid Control ECU Outputs the information about the speed of the right front wheel. This information is used by the automatic high beam sensor (inner rear view mirror assembly) to control switching between the high beams and low beams of the automatic high beam system. ECM Outputs a signal to indicate that the shift lever is in R. Based on this signal, the automatic high beam sensor (inner rear view mirror assembly) turns the high beams off. Combination Meter Assembly Displays the automatic high beam indicator light when it receives illuminate or blink request signals from the main body ECU (multiplex network body ECU). HINT: The automatic high beam indicator light flashes to inform the driver when the malfunction is in this system. The automatic high beam indicator light illuminates to inform the driver when the automatic high beam system is activated. The automatic high beam indicator light may turn off when there is bad weather (deep fog, heavy rain, etc.), an abnormal condition with front windshield (snow, ice, etc.), or an obstruction to the camera field of view (parking tag, etc.). Main Body ECU (Multiplex Network Body ECU) Receives the light control switch AUTO position and dimmer switch high position signals from the headlight dimmer switch assembly, and receives the automatic light control sensor signal to determine the low beam headlight illumination condition, and sends this information to the AFS ECU (headlight swivel ECU assembly). These are used to put the automatic high beam system in standby mode. Receives high beam drive request signals from the AFS ECU (headlight swivel ECU assembly), and activates the headlight solenoid built into the headlight unit by turning the Bi-XENON relay on to change the headlight from low beam to high beam. Performs illumination control for the automatic high beam system and stores Diagnostic Trouble Codes (DTCs) when the system malfunctions. Basic Function When all of the following conditions are met, the automatic high beam system is activated and the automatic high beam indicator light turns on: The engine switch is on (IG). The light control switch is in the AUTO position and the low beam headlights are on. The dimmer switch is in the high position. When all of the following conditions are met, the low beams automatically change to high beam after a short delay: Vehicle speed is more than approximately 20 mph (32 km/h). The area in front of the vehicle is dark. There are no oncoming vehicles with headlights on. There are no preceding vehicles with taillights on. There are few streetlights along the street ahead. When any of the following conditions are met, the high beams automatically change to low beams after a short delay: Vehicle speed is less than 20 mph (32 km/h). The level of ambient light is higher than a specified threshold. There are oncoming vehicles with headlights on. There are preceding vehicles with taillights on. There are several streetlights along the street ahead. When any of the following conditions are met, the automatic high beam system will be canceled and the indicator light will turn off. The engine switch is turned off. The light control switch is turned to any position except the AUTO position. The low beam headlights are turned off. The dimmer switch is moved to the low position. HINT: It is possible to manually switch between the high beams and low beams using either of the following operations: Turn the light control switch from the AUTO position to the head position. In this case, the high beams turn on according to the dimmer switch high position. To change to the low beams, move the dimmer switch to the low position. Move the dimmer switch from the high position to the low position. In this case, the low beams turn on according to the dimmer switch position. HINT: The automatic high beam system monitors the area in front of the vehicle using the camera built into the inner rear view mirror assembly and makes a judgment to change low beams to high beams when the surrounding area is dark (there are no headlights from oncoming vehicles and no taillights from vehicles in front). High beam control limitations: When the surrounding area is not dark enough, the low beams will not change to high beams even if the low beam headlights are turned on by the automatic light control system and the automatic high beam indicator light on the combination meter assembly illuminates. (The light level sufficient to turn the auto low beams on is not the same as the light level required to automatically change the low beams to high beams.) When an oncoming vehicle suddenly appears at a sharp curve or a vehicle crosses the path of the vehicle, the high beams may not change to low beams. When the fog lights of an oncoming vehicle are detected, the high beams may change to low beams. The timing of the change between high beams and low beams may differ depending on the brightness of headlights or fog lights from oncoming vehicles or the taillights of preceding vehicles. The timing of the change between high beams and low beams may differ between normal conditions (good weather) and when driving on wet, frozen or snowy roads. The timing of the change between high beams and low beams may differ depending on the number of occupants and amount of cargo present. Be aware that on some occasions, the high beams and low beams may change unexpectedly. HINT: The camera built into the inner rear view mirror assembly continually monitors the light level in the area to the front of the vehicle. There is a delay in switching the low beams to the high beams. Even when there is no ambient light, the low beams will not change to high beams immediately. The delay will vary depend on the situation.
  5. HID HEADLIGHT SYSTEM The High Intensity Discharge (HID) headlight system uses a discharge bulb as its light source for the low beam. Discharge bulbs are superior to halogen bulbs. Discharge bulbs have the following features: The light emitted by the bulb is close in color to sunlight. The light shines ahead over a broader area and further forward, increasing the area visible to the driver. Less power is consumed. This system consists of the discharge bulbs and light control ECUs. The light control ECU transforms voltage that is input from the battery to high voltage of up to 20000 V and applies it to the discharge bulbs in order to illuminate them.
  6. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM General When the low beam headlights are on, the automatic headlight beam level control system operates the headlight leveling motor in accordance with movement of the vehicle. The AFS ECU (headlight swivel ECU assembly) controls the system. Function of Main Components Component Outline AFS ECU (Headlight Swivel ECU Assembly) Receives various signals, calculates changes in the vehicle posture, and actuates the headlight leveling motor. Headlight Leveling Motor Based on the signals received from the AFS ECU (headlight swivel ECU assembly), the motors move the reflectors in the headlights to vary the low beam. Uses a stepper motor to precisely regulate the angle of the projectors. Rear Height Control Sensor Sub-assembly RH*1 Suspension Control ECU*2 Transmits a height control sensor signal to the AFS ECU (headlight swivel ECU assembly). Skid Control ECU Transmits a speed sensor signal (Front LH and RH) to the AFS ECU (headlight swivel ECU assembly). ECM Transmits an engine running status signal to the AFS ECU (headlight swivel ECU assembly). Main Body ECU (Multiplex Network Body ECU) Transmits a headlight status signal. Combination Meter Assembly AFS OFF Indicator Light*3 When the system malfunctions, the combination meter assembly alerts the driver by flashing the AFS OFF indicator light in accordance with the signal from the AFS ECU (headlight swivel ECU assembly). Multi-information Display*4 When the system malfunctions, the combination meter assembly illuminates the master warning light based on the signal from the AFS ECU (headlight swivel ECU assembly), and indicates the warning message on the multi-information display to alert the driver. *1: w/o Air Suspension *2: w/ Air Suspension *3: w/ AFS *4: w/o AFS Initial Set Control When the engine is started, the AFS ECU (headlight swivel ECU assembly) drives the headlight leveling motor and moves the headlight reflector to the lower limit position and returns it to the proper position. The AFS ECU (headlight swivel ECU assembly) thus assesses the position of the headlight for reference control. NOTE: Initialize the AFS ECU (headlight swivel ECU assembly) when the AFS ECU (headlight swivel ECU assembly) is replaced. If the vehicle is not equipped with air suspension system, initialize the AFS ECU (headlight swivel ECU assembly) (set the zero point of the height control sensor in the AFS ECU (headlight swivel ECU assembly)) after the vehicle height changes due to replacement of suspension components or after performing such operations as removal and reinstallation or replacement of the rear height control sensor sub-assembly RH.
  7. AFS (Adaptive Front-lighting System) General An Adaptive Front-lighting System (AFS) is used in order to ensure a wide low beam lighting area and realize excellent visibility during turns by moving the low beam. The AFS uses medium-to-high speed control and low speed control. Function of Main Components Component Outline AFS ECU (Headlight Swivel ECU Assembly) Receives various signals, calculates the target lighting angle, and actuates the headlight swivel actuator. Headlight Swivel Motor Driven by the AFS ECU (headlight swivel ECU assembly), the motor moves the low beam left or right to the angle calculated by the AFS ECU (headlight swivel ECU assembly). A step motor is used for the headlight swivel motor. The AFS ECU (headlight swivel ECU assembly) determines the low beam angle based on the number of steps (position) of the stepper motor. Steering Angle Sensor (Spiral Cable Sub-assembly) Detects the steering angle and direction and outputs this signal to the AFS ECU (headlight swivel ECU assembly). Steering Pad Switch Assembly Pressing this switch disables the operation of the AFS. Skid Control ECU Transmits a speed sensor signal (Front LH and RH) to the AFS ECU (headlight swivel ECU assembly). ECM Transmits an engine running status signal to the AFS ECU (headlight swivel ECU assembly). Transmits a shift position signal to the AFS ECU (headlight swivel ECU assembly). The AFS ECU (headlight swivel ECU assembly) determines whether the vehicle is moving forward or backward based on this signal. Main Body ECU (Multiplex Network Body ECU) Transmits a headlight status signal. Combination Meter Assembly AFS OFF Indicator Light When the system malfunctions, the combination meter assembly flashes the AFS OFF indicator light based on the signal from the AFS ECU (headlight swivel ECU assembly) to alert the driver. Low Speed Control The AFS ECU (headlight swivel ECU assembly) performs the low speed control when all of the following conditions are met: Engine is running. Vehicle is moving forward at a speed of 10 km/h (6 mph) or more. Vehicle is moving forward at a speed of less than 30 km/h (19 mph). Steering angle is 6° or more. Low beam headlights are on. Daytime running light function is not operating. AFS on/off condition is on. SWIVEL ANGLE RANGE Driving Condition Low Beam Left Right Right Turn 0° Fixed 0° to 10° to Right Left Turn 0° to 15° to Left 0° Fixed Medium-to-High Speed Control The AFS ECU (headlight swivel ECU assembly) performs the medium-to-high speed control when all of the following conditions are met: Engine is running. Vehicle is moving forward at a speed of 30 km/h (19 mph) or more. Steering angle is 7.5° or more. Low beam headlights are on. Daytime running light function is not operating. AFS on/off condition is on. SWIVEL ANGLE RANGE Driving Condition Low Beam Left Right Right Turn 0° Fixed 0° to 10° to Right Left Turn 0° to 15° to Left 0° Fixed Operation Stop Condition The AFS ECU (headlight swivel ECU assembly) stops the control when any of the following conditions is met: Engine is stopped. Vehicle is moving forward at a speed of less than 10 km/h (6 mph). Steering angle is less than 6°. Low beam headlights are off. Daytime running light function is operating. AFS on/off condition is off. Shift lever in R or N. Initial Set Control When the engine is started, the AFS ECU (headlight swivel ECU assembly) drives the headlight swivel motor and moves the projector headlight to the operation limit in the direction toward the vehicle center and returns it to the proper position. The AFS ECU (headlight swivel ECU assembly) thus assesses the position of the headlight for reference control. NOTE: Initialize the AFS ECU (headlight swivel ECU assembly) when the AFS ECU (headlight swivel ECU assembly) is replaced.
  8. DOOR MIRROR FOOT LIGHT SYSTEM General The door mirror foot light control consists primarily of the fade-in/fade-out function and timer illumination function. This control is controlled by the outer mirror control ECU assembly and main body ECU (multiplex network body ECU). The main body ECU (multiplex network body ECU) sends door mirror foot light on/off demand signals to the outer mirror control ECU assembly. According to various information, the outer mirror control ECU assembly performs fade-in/fade-out control of the door mirror foot lights. The door mirror foot light system has the following control functions: Function Outline Actuation Area-linked When all of the following conditions are met, the lights that operate turn on: The engine switch is off. All door are closed. A key is detected in the actuation area. When the following condition is met, the lights that operate turn off: A key is not detected in the actuation area. Door Unlock-linked When all of the following conditions are met, the lights that operate turn on: The engine switch is off. All door are closed. Any door is unlocked when all doors are locked. Door Lock-linked When either of the following conditions is met, the lights that operate turn off: All door are locked when all doors are closed and any door is unlocked. All doors are locked again when all doors are closed and locked. Door Control Switch-linked When all of the following conditions are met, the lights that operate turn on: The engine switch is on (IG). The shift lever is in P. Either driver door control switch or front passenger door control switch is turned to unlock position. Door Close-linked When the following condition is met, the lights that operate turn off: All doors are closed. Shift Lever Position-linked When both of the following conditions are met, the lights that operate turn off: The engine switch is on (IG). The shift lever is put into any position other than P. Delay When approximately 15 seconds elapse after any of the following conditions are met, the lights that operate turn off: An actuation area-linked function is used. The door unlock-linked function is active. Any door is opened and then closed. Battery Saving When no changes occur in the condition of the doors for 20 minutes and a key is not in the actuation area, these lights turn off.

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