System Description
WARNING: This page is about a different car, the 2023 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
SYSTEM DIAGRAM
OUTLINE
- The auto light system is controlled by each function of the BCM and IPDM E/R. Control by BCM:
- Combination switch reading function
- Auto light function
- Wiper linked auto lighting function
- Delay timer function
Control by IPDM E/R:
- Smart FET control function
- The auto light system has the auto light function, wiper linked auto lighting function, and delay timer function.
- The auto light function automatically turns ON/OFF the exterior lamps*, depending on the outside brightness.
- The wiper linked auto lighting function automatically turns ON/OFF the exterior lamps* when the lighting switch is in the AUTO position, according to front wiper operation.
- When the auto light system turns the headlamp ON with the ignition switch OFF, the delay timer function turns the headlamp OFF, depending on the vehicle condition with the auto light function after a certain period of time.
*: Headlamp (LO/HI), parking lamp, license plate lamp and tail lamp.
NOTE:
- Headlamp (HI) depend on the combination switch (lighting and turn signal) condition.
Signal transmission function list
| Signal name | Input | Output | Description |
|---|---|---|---|
| Combination switch signal | Combination switch (lighting and turn signal switch) | BCM | Transmits the combination switch signal to the BCM. |
| Optical sensor signal | Optical sensor | BCM | Transmits the optical sensor signal to the BCM. |
| Door switch signal | Door switch (ALL) | BCM | Transmits the door switch signal to the BCM. |
| Light request signal 1 | BCM | IPDM E/R (CAN) | Transmits the light request signal via CAN communication. |
| Light status signal 2 | BCM | Combination meter (CAN) | Transmits light status signal via CAN communication. |
1: High beam, low beam and position light request signal. 2
AUTO LIGHT FUNCTION
- The BCM detects the combination switch (lighting and turn signal switch) condition with the combination switch reading function.
- The BCM supplies voltage to the optical sensor when the ignition switch is ON.
- The optical sensor converts outside brightness (lux) to voltage and transmits the optical sensor signal to the BCM.
- When the ignition switch is ON, the BCM detects outside brightness from the optical sensor signal and judges the ON/OFF condition of each exterior lamp, depending on the outside brightness condition.
- The BCM transmits each request signal to the IPDM E/R and each status signal to the combination meter via CAN communication, according to ON/OFF condition by the auto light function.
WIPER LINKED AUTO LIGHTING FUNCTION
The BCM turns each exterior lamp ON within 60 seconds detecting 4 operations of the front wiper while the lighting switch is in the AUTO position.
NOTE:
The BCM turns OFF the headlamps 3 seconds after the front wiper switch is turned OFF.
DELAY TIMER FUNCTION
The BCM turns the headlamp OFF depending on the vehicle condition with the auto light function.
- Turns the headlamp OFF approx. 60 seconds after ignition switch OFF.
NOTE:
- Headlamp (HI) depend on the combination switch (lighting and turn signal switch) condition.
- When any position other than lighting switch AUTO is set, the auto light system function switches to the exterior lamp battery saver function.