System Description

SYSTEM DIAGRAM

Courtesy of NISSAN

OUTLINE

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

INPUT SIGNAL AND OUTPUT SIGNAL

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

Component parts	Signal description
BCM	BCM transmits sleep wake up signal to each unit when condition is established, and then goes into each mode.
IPDM E/R	Transmits the sleep-ready signal and wake up signal to BCM via CAN communication. Receives the sleep wake up signal from BCM via CAN communication.
Combination meter
CAN gateway
Intelligent Key unit

LOW POWER CONSUMPTION CONTROL WITH BCM

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

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

SLEEP MODE ACTIVATION

BCM receives the sleep-ready signal (ready) from IPDM E/R, combination meter, Intelligent Key unit and CAN gateway via CAN communication.
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 wake-up signal. BCM is in CAN communication sleep mode.
BCM is in the low power consumption mode and performs the 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 Push-button ignition switch: OFF 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

CAN sleep condition

BCM sleep condition

WAKE-UP OPERATION

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 BCM via CAN communication to report the CAN communication start.

BCM wake-up condition	CAN wake-up condition
Door lock switch: OFF->ON Door unlock switch: OFF->ON Back door switch assembly (opener switch) : OFF->ON	Receiving the sleep-ready signal (Not-ready) from any units Hazard switch: OFF->ON, ON->OFF PASSING LAMP switch: OFF->ON, ON->OFF TAIL LAMP switch: OFF->ON, ON->OFF Front door switch LH: OFF->ON, ON->OFF Front door switch RH: OFF -> ON, ON -> OFF Back door lock assembly (ajar switch) : OFF->ON, ON->OFF Stop lamp switch signal: ON Low beam switch: OFF->ON, ON->OFF High beam switch: OFF->ON, ON->OFF Push-button ignition switch: OFF->ON Rear door switch LH, RH: OFF -> ON, ON -> OFF FR FOG switch: OFF->ON, ON->OFF

BCM wake-up condition

CAN wake-up condition