Home ReviewsRefund
Home/Lexus/CT/Lexus CT I (2010-2014)/Repair manual/Exterior Lights/Lighting System (Diagnostics - Introduction): Overview
Contents Wiring diagrams Section: Exterior Lights All sections

Lighting System (Diagnostics - Introduction): Overview Lexus CT I

Exterior Lights ~1815 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, side 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 side marker lights). This system has the following functions. Function Outline Driver Door-linked Function The exterior lights automatically turn off when all of the following conditions are met: The power switch is turned from on (IG) to off. The light control switch is in the tail position. The driver door is opened. Delay Function The exterior lights automatically turn off after 30 seconds when all of the following conditions are met: The power 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 headlights (high-intensity parking lights), during the daytime to make the car more visible to other vehicles. There are 2 LED type parking light circuits in each headlight. One is for a conventional low-intensity parking light that illuminates with the taillights, and the other is for the high-intensity parking light that is used for the DRL system. These circuits are operated by the by the main body ECU (multiplex network body ECU). This system is enabled when the conditions given below are met (The headlight dimmer switch has DRL OFF function): Power switch on (IG) READY condition is received. Light control switch is in the tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). Parking brake switch off This system is enabled when the conditions given below are met (The headlight dimmer switch does not have DRL OFF function): Power switch on (IG) READY condition is received. Light control switch is in the off, tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). Parking brake switch off
  4. LED HEADLIGHT SYSTEM General LED headlights are used to provide efficient, maintenance free lighting. Compared to halogen or HID headlights, even if an LED headlight is used for a long time, the reduction of brightness over its lifetime is less. In addition, there is no possibility of an LED having an open circuit because of vibration. Function of Main Components Component Outline Light Control ECU Turns on the LEDs immediately when the light control switch is turned to the head position. Regulates the output current flowing into the LEDs at a specified level to prevent the light from getting brighter and dimmer due to voltage variation. Transmits fail signals to the main body ECU (multiplex network body ECU) when a malfunction occurs in the LED headlight system. Combination Meter Assembly Master Warning Light Flashes to inform the driver when the light control ECU detects malfunctions in this system. Multi-information Display Displays a warning message to inform the driver when the light control ECU detects a malfunction in this system. Main Body ECU (Multiplex Network Body ECU) Receives fail signals from the light control ECU when a malfunction occurs in the LED headlight system, and transmits the signals to the combination meter assembly. Stores Diagnostic Trouble Codes (DTCs) when the system malfunctions.
  5. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM General This system maintains the low beam headlights at a constant level while the vehicle is stopping. This system is controlled by the headlight leveling ECU assembly. The headlight leveling ECU assembly detects the vehicle posture via the rear height control sensor sub-assembly, and detects the vehicle speed via the combination meter assembly. The headlight leveling ECU assembly controls each headlight leveling motor based on these pieces of information in order to change the headlight reflector angle. NOTE: Initialize the rear height control sensor sub-assembly signal after the vehicle height changes due to replacement of the suspension or after operations as reinstallation or replacement of the rear height control sensor sub-assembly. When the headlight leveling ECU assembly is replaced, initialization is also necessary. Function of Main Components Component Outline Rear Height Control Sensor Sub-assembly Detects vehicle height. Combination Meter Assembly Outputs the vehicle speed signal to the headlight leveling ECU assembly. The headlight beam level control system indicator light in the combination meter illuminates for 3 seconds and then goes off when the power switch is turned on (IG) (bulb check function). The headlight beam level control system indicator light in the combination meter illuminates to alert the driver when a malfunction in this system is detected. Headlight Leveling Motor Based on the signals received from the headlight leveling ECU assembly, each motor moves the reflector in the headlight to vary its low beam. Headlight Leveling ECU Assembly Based on the signals that are transmitted by the rear height control sensor sub-assembly and combination meter assembly, the headlight leveling ECU assembly detects the amount of variance of the vehicle posture while the vehicle is stopping. Based on the detected value, the headlight leveling ECU assembly outputs control signals to the headlight leveling motor. The headlight leveling ECU assembly turns on the headlight beam level control system indicator light for 3 seconds when the power switch is turned on (IG) (bulb check function). The headlight leveling ECU assembly turns on the headlight beam level control system indicator light to alert the driver when a malfunction in this system is detected.
  6. 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 main body ECU (multiplex network body ECU). 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 power switch is off. All doors 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 power switch is off. All doors 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 doors 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 power switch is on (IG). Park (P) has been selected. Either the driver door control switch or front passenger door control switch is turned to the unlock position. Shift Lever Position-linked When both of the following conditions are met, the lights that operate turn off: The power switch is on (IG). The shift lever is moved to select a shift state other than park (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 doors are unlocked using the mechanical key, wireless function or door control switch.

OPERATION CHECK

  1. AUTOMATIC LIGHT CONTROL SYSTEM OPERATION CHECK Turn the power switch on (IG). Turn the light control switch to the AUTO position. Cover the automatic light control sensor. Check that the taillights and low beam headlights come on. Uncover the automatic light control sensor. Check that the low beam headlights and taillights go off.
  2. LIGHT AUTO TURN-OFF SYSTEM OPERATION CHECK When only the taillights are on: Close the driver door. Turn the power switch on (IG). Turn the light control switch to the tail position. Turn the power switch off. Open the driver door. Check that the taillights go off immediately. When the low beam headlights are on: Close all of the doors. Turn the power switch on (IG). Turn the low beam headlights, high beam headlights or front fog lights on. Turn the power switch off. Open any door. Close all of the doors. Check that all of the lights go off after 30 seconds (delay function). HINT: Before the lights go off, if the lock button on the key is pushed after all of the doors are locked, all of the lights will go off immediately.
  3. DAYTIME RUNNING LIGHT SYSTEM OPERATION CHECK The headlight dimmer switch has DRL OFF function: Turn the power switch on (READY). Light control switch is in the tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). Release the parking brake. Check that the daytime running lights (high-intensity LED parking lights) come on. The headlight dimmer switch does not have DRL OFF function: Turn the power switch on (READY). Light control switch is in the off, tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). Release the parking brake. Check that the daytime running lights (high-intensity LED parking lights) come on.
  4. DOOR MIRROR FOOT LIGHT SYSTEM OPERATION CHECK The operation and condition of this control are described below. Operation Condition Illuminate for 15 seconds, and then fade out When any of the following conditions is met, the lights illuminate for 15 seconds, and then fade out: The key enters any actuation area around the doors when the power switch is off and all doors are closed.*1 Any door is unlocked when the power switch is off and all doors are closed and locked. Either the driver door control switch or front passenger door control switch is turned to unlock position when the power switch is on (READY) and park (P) has been selected. Fade out immediately When any of the following conditions is met, the lights fade out immediately: All doors are locked when the power switch is off, all doors are closed and any door is unlocked. All doors are locked again when all doors are closed and locked. The shift lever is moved to select a shift state other than park (P) when the power switch is on (READY). HINT: *1: When the lights are on, if the key leaves the actuation areas around the doors, after approximately 3 seconds, the door mirror foot lights fade out.

See also:
• REMOVAL

More articles — Lighting System (Diagnostics - Introduction)