LIGHTING SYSTEM SYSTEM DESCRIPTION

AUTOMATIC LIGHT CONTROL SYSTEM

1. General

   When the light control switch is in the AUTO position, the automatic light control sensor detects ambient light levels and outputs a signal to the main body ECU. The main body ECU controls the low beam headlights, front clearance lights, taillights and license plate lights according to the signal from the automatic light control sensor.

2. Fail-safe

   If the main body ECU detects a malfunction in the rain sensor, the main body ECU performs fail-safe control to prohibit automatic light control. If the headlights or taillights are on, the lights remain on until the light control switch is turned off.

LIGHT AUTO TURN-OFF SYSTEM

• *: w/ Front Fog Light

1. General

   The light auto turn-off system is used to prevent the driver from leaving the vehicle with the headlights, front fog lights*, rear fog light, front clearance lights, taillights or license plate lights on.

2. When the light control switch is in the AUTO position and the driver side door is opened with the ignition switch off, the headlights, front fog lights*, rear fog light, clearance lights, taillights and license plate lights turn off.

3. When the ignition switch is turned off with the light control switch in the head position, the headlights and front fog lights* turn off.

4. When the ignition switch is turned off with the light control switch in the tail position, the front fog lights turn off.*

HID HEADLIGHT SYSTEM

1. General

   The HID (High Intensity Discharge) headlight system uses a discharge bulb as its light source for the low beam headlight.

   
   

   • 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 ECU.

   • The light control ECU transforms the voltage that is input from the battery to a high voltage of up to 22000 V and applies it to the discharge bulbs in order to illuminate them.

   • A fail-safe function is provided as a countermeasure against the high voltage that is generated if a problem occurs in the headlight system.

DAYTIME RUNNING LIGHT SYSTEM

1. This system is designed to automatically activate the low beam headlights, taillights, clearance lights, and license plate lights during the daytime to keep the car highly visible to other vehicles.

   
   

   • The main body ECU (instrument panel junction block assembly) controls this system.

   
   

   • This system is enabled when the conditions below are met:

   
   

   • The ignition switch is ON.

   
   

   • An engine speed signal is input (the engine is running).

   • The light control switch is in the off or AUTO position (and the taillights are not turned on via the automatic light control system).

MANUAL HEADLIGHT BEAM LEVEL CONTROL SYSTEM

1. When the vehicle posture changes in accordance with the number (weight) of passengers and volume of luggage, this system enables the adjustment of the LO beam level (11 steps) of the headlights manually to the appropriate level based on the position of the headlight leveling switch.

   
   

   • The beam level of the headlight can be adjusted by the headlight leveling motor that is installed in the headlight assembly.

   • The headlight leveling switch allows the driver to control this system.

AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM

1. General

   
   

   • This system adjusts the headlight LO beams when the vehicle is stopped to maintain a constant level.

   • This system is controlled by the headlight leveling ECU. This ECU detects the vehicle posture via the rear height control sensor, and detects the vehicle speed via the combination meter. The ECU then controls the headlight leveling motor based on these pieces of information in order to change the headlight reflector angle.

   Note

   
   

   • Initialize the height control sensor signal after the vehicle height changes due to replacement of the suspension or after performing such operations as removal and reinstallation or replacement of the rear height control sensor sub-assembly.

   • Initialization is also necessary when the headlight leveling ECU is replaced.

2. Function and construction of components

   Components	Function and Construction
   Rear Height Control Sensor	Detects the vehicle height.
   Combination Meter	Outputs the vehicle speed signal to the headlight leveling ECU. Headlight beam level control system warning light in the combination meter illuminates for 3 seconds and then turns off when the ignition switch is turned to ON (bulb check function). Headlight beam level control system warning 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, each motor moves the reflector in the headlight to vary its LO beam height.
   DLC3	The height control sensor signal initialization and headlight leveling motor operation check can be performed via the DLC3.
   Headlight Leveling ECU	Based on the signals that are transmitted by the height control sensor and combination meter, this ECU detects the amount of variance of the vehicle posture with the vehicle stopped. Based on the detected value, this ECU outputs control signals to the headlight leveling motor. This ECU turns on the headlight beam level control system warning light for 3 seconds when the ignition switch is turned to ON (bulb check function). This ECU turns on the headlight beam level control system warning light to alert the driver when a malfunction in this system is detected.

3. Fail-safe

   The headlight leveling ECU operates in fail-safe mode if an abnormal condition has been detected, and illuminates the automatic headlight beam level control system warning light in the combination meter when a malfunction is detected in the headlight beam level control system.