System Description

SYSTEM DIAGRAM

Component		Function
Headlight	Headlight (HI) (LED headlight)	LED headlight control module supplies power supply voltage to headlight (HI), and turns the headlight (HI) ON. Exterior light appearance: Refer to Exterior Light AppearanceExterior Light Appearance. Bulb specifications: Refer to Bulb Specifications.
	Headlight (LO) (LED headlight)	LED headlight control module supplies power supply voltage to headlight (LO), and turns the headlight (LO) ON. Exterior light appearance: Refer to Exterior Light AppearanceExterior Light Appearance. Bulb specifications: Refer to Bulb Specifications.
	LED headlight control module	Refer to LED Headlight Control ModuleLED Headlight Control Module.
IPDM E/R		Transmits the control signal and request (via LIN communication) to the LED headlight control module according with the request from BCM via CAN communication. Detects the LIN communication error or headlight warning signal is input from the LED headlight control module (via LIN communication). And the IPDM E/R requests the combination meter (via CAN communication) to displays the headlight warning.
BCM		Detects each switch condition by the combination switch reading function. Headlight (HI/LO) ON/OFF is judged from each signal, and then a request is transmitted to IPDM E/R (via CAN communication) to controls the LED headlight control module. It also transmits a status to the combination meter (via CAN communication) to turns dipped beam indicator light and high beam indicator light ON/OFF.
Combination meter		Turns the high beam indicator light ON/OFF according to the status from BCM via CAN communication. Displays the headlight warning according to the request from IPDM E/R via CAN communication.
Combination switch	Lighting & turn signal switch	Inputs the each switch condition signal to BCM.

OUTLINE

Headlight is controlled by combination switch reading function and headlight control function of BCM, and smart FET control function and LIN communication function of IPDM E/R.

HEADLIGHT (LO) OPERATION

BCM detects the combination switch condition with the combination switch reading function.
BCM transmits the low beam request signal to IPDM E/R and low beam status signal to the combination meter via CAN communication according to the headlight (LO) ON condition.
Headlight (LO) ON condition (When any of the following conditions are satisfied)
- Lighting switch 1ST (Only when the illumination judgment by auto light function is ON. Refer to System Description) (For Canada)
- Lighting switch 2ND
- Lighting switch AUTO (Only when the illumination judgment by auto light function is ON. Refer to System Description.)
- Lighting switch PASS
IPDM E/R turns the integrated smart FET ON according to low beam request signal, and transmits the control signal to LED headlight control module.
IPDM E/R transmits the request to LED headlight control module (via LIN communication) according to low beam request signal.
LED headlight control module turns the headlight (LO) ON according to the control signal and request (via LIN communication) from IPDM E/R.

HEADLIGHT (HI) OPERATION

BCM transmits the high beam request signal to IPDM E/R and high beam status signal to the combination meter via CAN communication according to the headlight (HI) ON condition.
Headlight (HI) ON condition (When any of the following conditions are satisfied)
- Lighting switch HI with the lighting switch 2ND
- Lighting switch HI with the lighting switch AUTO (Only when the illumination judgment by auto light function is ON. Refer to System Description.)
- High beam assist switch ON with the lighting switch 1ST or AUTO (Only when the illumination judgment by auto light function is ON and the illumination judgment by high beam assist system is ON. Refer toSystem Description.)
- Lighting switch PASS
IPDM E/R turns the integrated smart FET ON according to high beam request signal, and transmits the control signal to LED headlight control module.
IPDM E/R transmits the request to LED headlight control module (via LIN communication) according to high beam request signal.
LED headlight control module turns the headlight (HI) ON according to the control signal and request (via LIN communication) from IPDM E/R.
Combination meter turns the high beam indicator light ON according to the high beam status signal.

HEADLIGHT WARNING OPERATION

Headlight warning warns the driver that there is a malfunction in LED headlight system. Refer to Headlight WarningHeadlight Warning

LED HEADLIGHT

Semiconductor device (Light emitting diode: LED), which is illuminated when forward bias electric voltage is applied, is adopted as the source of light instead of halogen bulb or xenon bulb.
Comparing to halogen headlight or xenon headlight, LED headlight is electrically power saving, durable, and is illuminated in the similar color to the sunlight. Bright, natural, and eye-friendly visibility can be obtained.

Precautions for Trouble Diagnosis

Representative malfunction examples are; “Light does not turn ON”, “Light blinks”, and “Brightness is inadequate.” Such malfunctions, however, occasionally by occur LED control module malfunction or light case malfunction. Specify the malfunctioning part with diagnosis procedure.

caution

Never touch the harness, LED headlight control module, the inside and metal part of light when turning the headlight ON or operating the lighting switch, for preventing electrical shock.
Never work with wet hands, for preventing electrical shock.
Never perform LED headlight control module circuit diagnosis with a circuit tester or an equivalent.
Temporarily install the headlights on the vehicle. Always connect power supply to the connector (vehicle side) when checking ON/OFF status.
Disconnect the battery negative terminal before disconnecting the light socket connector or the harness connector.
Check for blown (open) of the fusible link(s), open around connector, short, disconnection if the symptom is caused by electric error.
Always check for deformation or hole of headlight housing and engagement of bulb cover. Otherwise, water may enter into headlight because of damage of headlight housing and contact to LED headlight control module connector. The normal operation may be inhibited when short circuit to power supply is detected.

note	Turn the switch OFF once before turning ON, if the ON/OFF is inoperative.