Exterior Lighting System
LIGHTING (EXT): LIGHTING SYSTEM: SYSTEM DIAGRAM
Various switches or sensors are represented as inputs for the different systems mentioned in the section. Where direct electrical connections do not exist between components, signals may be carried across the different networks (BEAN, CAN) that exist on the vehicle. If a signal needs to travel from the CAN network to the BEAN network, the gateway ECU allows the signal to travel between these different networks. Some of these different signals can be confirmed or inspected using the Techstream.
SYSTEM DESCRIPTION
1. AUTOMATIC LIGHT CONTROL SYSTEM
(a) General
(1) When the light control switch is in the AUTO position, the automatic light control system detects ambient light levels and controls the headlights, parking lights, taillights, marker lights, and license plate lights.
2. MANUAL LIGHT CONTROL SYSTEM
(a) The function of the system is similar to the automatic light control system, except the system is controlled according to the driver's operations.
3. LIGHT AUTO TURN-OFF SYSTEM (w/ Occupant Classification System)
The light auto turn-off system is used to prevent forgetting to turn off the exterior lights (headlights, front fog lights, taillights, parking lights, license plate lights).
This system has the following functions.
4. LIGHT AUTO TURN-OFF SYSTEM (w/o Occupant Classification System)
(a) General
The light turn-off system is used to prevent the driver from leaving the vehicle with the headlights, front fog lights, parking lights, taillights or license plate lights on.
(b) When all of the following conditions are met, the headlights, front fog lights, parking lights, taillights and license plate lights turn off:
The engine switch is turned from on (IG) to off.
The headlights, front fog lights, parking lights, taillights or license plate lights are on.
The driver side door is opened.
5. BI-FUNCTION
(a) The models with HID (High Intensity Discharge) headlights have a Bi-function. This Bi-function increases the upper illumination area of the discharge bulb (low/high beam) when the high beam is turned on.
If the low beam is selected, the upper illumination area of the discharge bulb is blocked by a shade and only the lower illumination area is used. If the high beam is selected, the headlight solenoid slides the shutter (shade) down to allow use of the upper illumination area, thus increasing the illumination area and improving visibility when the high beam is on.
This function is activated by the front controller. The front controller receives a high beam turn on signal from the main body ECU RH and activates the headlight solenoid built into the headlight unit to slide the shade down.
6. HID HEADLIGHT SYSTEM
(a) This system consists of the light control switch, windshield wiper switch assembly, main body ECU RH, HEAD LP relay, discharge bulbs, and light control ECUs.
The main body ECU RH controls the low beam illumination using the HEAD LP relay.
The BEAN network is used for communications.
A HEAD backup link exists between the windshield wiper switch and the main body ECU RH.
The light control ECUs transform the voltage that is input from the battery to a high voltage of up to 22000 V and apply this voltage to the discharge bulbs in order to illuminate them.
A fail-safe function is provided as a countermeasure against high voltage generated in case a problem occurs in the headlight system.
NOTICE:
For safety reasons, do not attempt to measure the voltage output from a light control ECU.
7. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM
(a) When the headlights are on, the automatic headlight beam level control system operates the headlight level actuators in accordance with the movement of the vehicle.
The automatic headlight beam level control system mainly consists of the headlight leveling ECU assembly, front height control sensor, rear height control sensor, and two headlight level actuators. The headlight leveling ECU assembly controls the system.
The ECU detects the movement of the suspension from the front and rear height control sensors, and the vehicle speed from the front RH and LH speed sensors.
The ECU then controls the headlight level actuator based on this information, in order to change the headlight reflector angle.
(b) Initial Set Control
The headlight leveling ECU assembly executes the initial setting of the stepper motors at engine-start.
(c) Fail-Safe Function
If the headlight leveling ECU assembly detects a malfunction in the automatic headlight beam level control system, the headlight leveling ECU assembly effects fail-safe control. At the same time, the headlight leveling ECU assembly indicates the system warning on the multi-information display in order to inform the driver of the problem.
8. DAYTIME RUNNING LIGHT SYSTEM
(a) 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 via independent IC relays in the front controller.
The main body ECU RH and front controller control this system. The main body ECU RH transmits a turn ON signal to the front controller, and the front controller illuminates the high-intensity parking lights.
This system is enabled when the conditions below are met:
* Engine switch is on (IG)
* Engine speed signal is input (engine running condition)
* Light control switch is in off, tail, or AUTO position (if headlight-on control is not being performed by the automatic light control)
* Parking brake switch is off
9. TURN SIGNALS
(a) The turn signals are front and rear lights that can be used to indicate a change of vehicle direction.
The turn signal switch signals are received by the windshield wiper switch assembly (combination switch ECU).
The main body ECU LH operates the turn signal flasher.
The turn signal flasher operates the signal lights.
10. HEADLIGHT CLEANER SYSTEM
(a) Some vehicles are provided with a headlight cleaner system. More details on the headlight cleaner system operation can be found in the wiper section.