System Description

SYSTEM DIAGRAM 

Fig 1: Power Consumption Control System Diagram

Courtesy of NISSAN NORTH AMERICA, INC.

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

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 a 10 ms interval to a 60 ms interval.

SLEEP MODE ACTIVATION

• BCM receives the sleep-ready signal (ready) from IPDM E/R and combination meter 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 wakeup 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.

WAKE-UP OPERATION

• BCM changes from the low power consumption mode to the CAN communication sleep mode when the any of the BCM wake-up conditions are fulfilled. Only the control with BCM is activated.
• 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.