Body Control System

System Description

System Description

OUTLINE

• The BCM controls the various electrical components. It inputs the information required for control via CAN communication and the signal received from each switch and sensor.

• The BCM has a combination switch reading function for reading the operation status of the combination switches (lighting, turn signal, wiper and washer) in addition to a function for controlling the operation of various electrical components. It also has the signal transmission function as the passed point of the signal and the a power saving control function that reduces the power consumption with the ignition switch OFF.

• The BCM is equipped with the diagnosis function that performs diagnosis and various settings with CONSULT.

BCM CONTROL FUNCTION LIST

System		Reference
Combination switch reading system		System Description
Signal buffer system		System Description
Power consumption control system		System Description
Shipping mode control system		System Description
Auto light system		System Description (Halogen headlamp) System Description (LED headlamp)
Headlamp system		System Description (Halogen headlamp) System Description (LED headlamp)
HBA (high beam assist) system		System Description (Halogen headlamp) System Description (LED headlamp)
Daytime running light system		System Description (Halogen headlamp) System Description (LED headlamp)
Turn signal and hazard warning lamp system		System Description (Halogen headlamp) System Description (LED headlamp)
Parking, license plate, side marker and tail lamp system		System Description (Halogen headlamp) System Description (LED headlamp)
Stop lamp system		System Description (Halogen headlamp) System Description (LED headlamp)
Exterior lamp battery saver system		System Description (Halogen headlamp) System Description (LED headlamp)
Light reminder warning		System Description (Halogen headlamp) System Description (LED headlamp)
Headlamp warning		System Description
Illumination control system		System Description
Interior room lamp control system		System Description
Interior room lamp battery saver system		System Description
Front wiper and washer system		System Description
Rear window defogger system		System Description
Warning chime system		System Description
Power door lock system		System Description
Trunk lid opener system		System Description
Intelligent Key system/engine start function		System Description
Nissan anit-theft system (NATS)		System Description
Nissan Sentra Vehicle security system		System Description
Panic alarm
Intelligent Key system	Intelligent Key system	System Description
	Remote engine start function	System Description
	Remote keyless entry function	System Description
	Door lock function	System Description
	Warning function	System Description
Power window system		System Description
RAP (retained accessory power) system		—
TPMS (tire pressure monitoring system)		System Description

Combination Switch Reading System

System Description

System Description

SYSTEM DIAGRAM

OUTLINE

• The BCM reads the status of the combination switch and recognizes the status of each switch.

• The BCM has a combination of 6 input terminals (INPUT 1 - 6) and 6 output terminals (OUTPUT 1 - 6) and reads a maximum of 22 switch states.

COMBINATION SWITCH MATRIX

Combination switch INPUT-OUTPUT system list

System	INPUT 1	INPUT 2	INPUT 3	INPUT 4	INPUT 5	INPUT 6
OUTPUT 1	Check diode 1	INT volume 1	Front washer switch	Front wiper LO	INT volume 2	Front wiper OFF
OUTPUT 2	High beam switch	Check diode 2	Rear washer switch	Front wiper HI	INT volume 3	Front wiper MIST
OUTPUT 3	Passing switch	Low beam switch	Check diode 3	Front wiper INT	Rear wiper INT	—
OUTPUT 4	Rear fog switch	AUTO light switch	Turn signal LH	Check diode 4	Rear wiper ON	—
OUTPUT 5	Front fog switch	Tail lamp switch	Turn signal RH	Light OFF switch	Check diode 5	—
OUTPUT 6	—	—	—	—	—	Check diode 6

COMBINATION SWITCH READING FUNCTION

Description

• The BCM reads the status of the combination switch at 10 ms intervals normally.

  

• The BCM operates as follows and judges the status of the combination switch:

  • It operates the transistor on INPUT side in the following order: OUTPUT 6–> 5 –> 4 –> 3 –> 2 –> 1, and outputs voltage waveform.

  • The voltage waveform of OUTPUT corresponding to the formed circuit is input into the interface on the INPUT side if any (1 or more) switches are ON.

  • It reads this change of the voltage as the status signal of the combination switch.

    

Operation Example

In the following operation example, the combination of the status signals of the combination switch is replaced as follows: INPUT 1 - 6 to “ - ” and OUTPUT 1 - 6 to “ - ”.

Example 1: When a switch (turn signal RH) is turned ON

• The circuit between INPUT 3 () and OUTPUT 5 () is formed when the turn signal RH is turned ON.

  

• The BCM detects the combination switch status signal “” when the signal of INPUT 3 is input to OUTPUT 5.

• The BCM judges that the turn signal RH is ON when the signal “” is detected.

Example 2: When multiple switches (front fog switch, turn signal RH) are turned ON

• The circuits between INPUT 1 () and OUTPUT 5 () and between INPUT 3 () and OUTPUT 5 () are formed when the front fog switch and turn signal RH are turned ON.

  

• The BCM detects the combination switch status signal “” when the signals of INPUT 1 and INPUT 3 are input to OUTPUT 5.

• The BCM judges that the front fog switch and turn signal RH are ON when the signal “” is detected.

WIPER INTERMITTENT DIAL POSITION (WITH WIPER INTERMITTENT DIAL POSITION)

The BCM judges the wiper intermittent dial 1 - 5 by the status of INT volume 1, 2 and 3 switches.

Wiper intermittent dial position	Switch status
	INT volume 1	INT volume 2	INT volume 3
1	ON	ON	OFF
2	ON	OFF	OFF
3	OFF	OFF	OFF
4	OFF	OFF	ON
5	OFF	ON	ON

Note:

For details of wiper intermittent dial position, refer to System Description.

Signal Buffer System

System Description

System Description

SYSTEM DIAGRAM

OUTLINE

The BCM has the signal transmission function that outputs/transmits each input/received signal to each unit.

Signal transmission function list

Signal name	Input	Output	Description
Stop lamp switch signal	Stop lamp switch	Each unit (CAN)	Inputs the stop lamp switch signal and transmits it via CAN communication.
Turn indicator signal	Combination switch (lighting and turn signal switch)	Each unit (CAN)	Inputs the turn indicator signal and transmits it via CAN communication.

Power Consumption Control System

System Description

System Description

SYSTEM DIAGRAM

INPUT SIGNAL AND OUTPUT SIGNAL

Major signal transmission between each unit via communication is shown in the following table:

Component parts	Signal description
IPDM E/R	Each unit transmits the sleep-ready signal (ready) to the BCM when all of the CAN sleep conditions are fulfilled. Each unit transmits the wake up signal to the BCM when all of the CAN sleep conditions are fulfilled. Each unit receives the sleep wake up signal (sleep) from the BCM via CAN communication. Each unit receives the sleep wake up signal (wake up) from the BCM via CAN communication.
Combination meter
Intelligent Key unit
AV control unit
8CH CAN gateway
BCM	BCM transmits the sleep wake up signal (sleep) to each unit when all of the CAN sleep conditions are fulfilled. BCM transmits the sleep wake up signal (wake up) to each unit when all of the CAN sleep conditions are fulfilled. BCM receives the sleep-ready signal (ready) from each unit via CAN communication. BCM receives the wake up signal from each unit via CAN communication.

System Description

OUTLINE

• The BCM incorporates a power saving control function that reduces power consumption according to the Nissan Sentra vehicle status.

• The BCM switches the status (control mode) by itself with the power saving control function. It performs the sleep request to each unit (IPDM E/R and combination meter) that operates with the ignition switch OFF.

  Normal mode (wake-up)

  • CAN communication is normally performed with other units

  • Each control with BCM is operating properly

  CAN communication sleep mode (CAN sleep)

  • CAN transmission is stopped

  • Control with BCM only is operating

  Low power consumption mode (BCM sleep)

  • Low power consumption control is active

  • CAN transmission is stopped

LOW POWER CONSUMPTION CONTROL WITH BCM

The BCM reduces power consumption with the following operation in low power consumption mode:

• The reading interval of each switch changes from 10 ms interval to 60 ms interval.

Sleep mode activation

• The BCM receives the sleep-ready signal (ready) from the IPDM E/R and combination meter via CAN communication.

• The BCM transmits the sleep wake up signal (sleep) to each unit when all of the CAN sleep conditions are fulfilled.

• Each unit stops the transmission of CAN communication with the sleep wakeup signal.

• The BCM is in low power consumption mode and performs low power consumption control when all of the BCM sleep conditions are fulfilled with CAN sleep condition.

Sleep condition

CAN sleep condition

BCM sleep condition

Receiving the sleep-ready signal (ready) from all units Ignition switch: OFF Nissan Sentra Vehicle security system alarm and panic alarm: No operation Warning lamp: No operation Intelligent Key warning buzzer: No operation Stop lamp switch: OFF Turn signal indicator lamp: No operation Exterior lamp: OFF Door lock status: No change CONSULT communication status: No communication Meter display signal: Non-transmission Door switch status: No change Rear window defogger: OFF

Interior room lamp battery saver: Time out RAP system: OFF Push-button ignition switch illumination: OFF NATS: No operation TPMS: Stop

Wake-up operation

• The BCM transmits the sleep wake up signal (wake up) to each unit when any of the CAN wake-up conditions are fulfilled. It changes from the low power consumption mode or the CAN communication sleep mode to the normal mode.

• Each unit starts the transmission of CAN communication with the sleep wake up signal. In addition, the combination meter transmits the wake up signal to the BCM via CAN communication to report the CAN communication start.

BCM wake-up condition

CAN wake-up condition

Front door lock assembly LH: Lock or unlock Door lock switch: OFF→ON Door unlock switch: OFF→ON Trunk lid opener switch: OFF→ON Intelligent Key unit: Receiving valid keyfob

Receiving the sleep-ready signal (not-ready) from any units Ignition switch: OFF→ON Hazard switch: OFF→ON Passing switch: OFF→ON, ON→OFF Tail lamp switch: OFF→ON Front door switch LH: OFF→ON, ON→OFF Front door switch RH: OFF → ON, ON → OFF Trunk lid opener assembly (ajar switch): OFF→ON, ON→OFF Front door request switch LH: OFF→ON Front door request switch RH: OFF→ON Stop lamp switch signal: ON Intelligent Key unit: Receiving valid keyfob

Shipping Mode Control System

System Description

System Description

SYSTEM DIAGRAM

OUTLINE

The BCM has the shipping mode control system function that reduces the drain on the battery during extended storage.

Signal transmission function list

Signal name	Input	Output	Description
Shipping mode status signal	BCM	Combination meter (CAN)	Transmits the shipping mode status signal via CAN communication.

DESCRIPTION

• The BCM switches the status (shipping mode or normal mode) by itself according to the extended storage switch condition, and transmits the shipping mode status signal to the combination meter and each unit via CAN communication.

• When the shipping mode function is activated, the control units will not detect DTCs.

• BCM control functions are limited in shipping mode. Refer to Description.

• When the BCM is in shipping mode, a message may be shown in the combination meter or information display.

• For shipping mode cancel operation, refer to Work Procedure.