System Description

AUTO LIGHT SYSTEM


System Description


OUTLINE
- Auto light system is controlled by each function of BCM and IPDM E/R.

Control by BCM
- Combination switch reading function
- Headlamp control function
- Auto light function
- Delay timer function
- Wiper linked auto lighting function

Control by IPDM E/R
- Relay control function
- Auto light system has the auto light function (with twilight lighting function*1), wiper linked auto lighting function and delay timer function.
*1:For USA only

- Auto light function automatically turns ON/OFF the exterior lamps *2 and each illumination automatically, depending on the outside brightness.
- Wiper linked auto lighting function automatically turns ON/OFF the exterior lamps* and each illumination when the light switch is in the AUTO position, according to a front wiper operation.
- When auto light system turns the exterior lamps ON with the ignition switch OFF, delay timer function turns the exterior lamps OFF, depending on the vehicle condition with the auto light function after a certain period of time.
*2: Headlamp (LO/HI), parking lamp (illuminated as front side marker lamps too), tail lamp, rear side marker lamp and front fog lamp (Headlamp HI and front fog lamp depend on the combination switch condition.)

NOTE:
The settings of the twilight lighting function and the wiper linked auto lighting function can be changed with CONSULT-III. Headlamp.

AUTO LIGHT FUNCTION (WITH TWILIGHT LIGHTING FUNCTION)

Description
- BCM detects the combination switch condition with the combination switch reading function.
- BCM supplies voltage to the optical sensor when the ignition switch is turned ON or ACC.
- Optical sensor converts outside brightness (lux) to voltage and transmits the optical sensor signal to BCM.
- BCM detects outside brightness from the optical sensor signal and judges ON/OFF condition of the exterior lamp and each illumination, depending on the outside brightness condition (standard or twilight).
- BCM transmits each request signal to IPDM E/R via CAN communication, according to ON/OFF condition by the auto light function.

NOTE:
As to ON/OFF timing, the sensitivity depends on setings. The settings can be changed with CONSULT-III. Headlamp.

Auto Lighting Timing Table
When the light switch is in AUTO position and the ignition switch is ON, the exterior lamps turns ON/OFF in the following condition.






Standard Light ON
BCM turns exterior lamps ON when outside brightness obtained from the optical sensor signal is 1250 lx or less for 3 seconds or more. And BCM turns exterior lamp OFF when outside brightness from the optical sensor signal is 2500 lx or more for 5 seconds or more.

Twilight Light ON (Twilight Lighting Function)
BCM detects twilight by filtered brightness.
- BCM filters outside brightness to block the impact of the rapid change in brightness, based on the optical sensor signal, and judges outside brightness.
- BCM detects changes in outside brightness, based on outside brightness obtained from the optical sensor signal and filtered brightness and judges ON/OFF of the exterior lamps.
Filtering chart





- BCM starts filtering 0.3 seconds after the ignition switch is turned ON and the light switch is turned to AUTO.
- BCM filters signals from the optical sensor at intervals of 2 seconds.When the filtered brightness is higher than outside brightness (signal from the optical sensor), BCM decreases the filtered brightness by 20 lx*.When the filtered brightness is lower than outside brightness, BCM increases the filtered brightness by 20 lx*.
- BCM turns ON the exterior lamps when filtered brightness reaches 3000 lx and turns OFF when reaching 5000 lx.
*:When vehicle speed is 5 km/h or less, BCM decreases/increases the filtered brightness by 5 lx.

WIPER LINKED AUTO LIGHTING FUNCTION
BCM turns the exterior lamp ON when detecting 4 operations of the front wiper worth the light switch in AUTO position.

NOTE:
BCM turns OFF the headlamps 3 seconds after the front wiper switch is turned from HI-->OFF.

DELAY TIMER FUNCTION
BCM turns the exterior lamp OFF depending on the vehicle condition with the auto light function when the ignition switch is turned OFF.
- Turns the exterior lamp OFF 5 minutes after detecting that any door opens (Door switch ON).
- Turns the exterior lamp OFF a certain period of time* after closing all doors (Door switch ON to OFF).
- Turns the exterior lamp OFF with the ignition switch ACC or the light switch OFF.
*: The preset time is 45 seconds. The timer operating time can be set by CONSULT-III. Headlamp.

NOTE:
When any position other than the light switch AUTO is set, the auto light system function switches to the exterior lamp battery saver function.