Nissan Pathfinder: Power Control System - System Description

Nissan Pathfinder (R53) 2022-2025 Service Manual / Electrical & Power Control :: Power Control System / Power Distribution System / System Description

Component Parts
System
Diagnosis System (bcm)
Diagnosis System (ipdm E/r)
Diagnosis System (intelligent Key Unit)

Component Parts Nissan Pathfinder Fifth generation

Power Distribution System

Component Parts Location

Instrument panel assembly

Fuse block (J/B) [view with fuse block (J/B) removed]

Brake pedal assembly (view with brake pedal assembly removed)

No.	Component	Function
1.	Rear door lock assembly RH (door switch)	Transmits the door switch signal to the BCM. Refer to Door Lock Assembly for detailed component location.
2.	Rear door request switch RH (if equipped)	Transmits the door request switch signal to the Intelligent Key unit. Refer to Door Request Switch for detailed component location.
3.	Front door lock assembly RH (door switch)	Transmits the door switch signal to the BCM. Refer to Door Lock Assembly for detailed component location.
4.	Front door request switch RH	Transmits the door request switch signal to the Intelligent Key unit. Refer to Door Request Switch for detailed component location.
5.	Electric shift control module	Transmits the shift position signal to the BCM via CAN communication. Refer to Electric Shift Control Module for detailed component location.
6.	Intelligent Key unit	The Intelligent Key Unit receives the push-button ignition switch input and transmits the signal to the BCM and IPDM E/R via CAN communication. Refer to Intelligent Key Unit for detailed component location.
7.	ABS (Anti-lock Braking System) actuator and electric unit (control unit)	Transmits the Nissan Pathfinder vehicle speed signal to the BCM via CAN communication. Refer to ABS Actuator and Electric Unit (Control Unit) for detailed component location.
8.	TCM (Transmission Control Module)	The TCM transmits P (park) and N (neutral) signals to the BCM via CAN communication. Refer to TCM for detailed component location.
9.	IPDM E/R (Intelligent Power Distribution Module Engine Room)	The IPDM E/R receives ignition relay (IPDM E/R) control signal and push-button ignition switch ON signal from the Intelligent Key unit via CAN communication, and controls the ignition relay (built into IPDM E/R). Refer to System Description.
10.	Ignition relay-3	The ignition relay-3 is controlled by the BCM. The ignition relay-3 supplies push-button ignition switch ON power supply or push-button ignition switch ON signal to each ECU and system when the push-button ignition switch is placed ON. The BCM compares the status of the ignition relay-3 control signal and push-button ignition status judged by the push-button ignition switch. The BCM monitors the ignition relay-3 operating status by the ignition relay-3 feedback signal.
11.	BCM (Body Control Module)	The BCM controls the power distribution system. The BCM judges the push-button ignition status and Nissan Pathfinder vehicle condition. The BCM checks the push-button ignition status internally. Refer to System Description.
12.	Front power window motor LH	Transmits the front power window open/close signal to the BCM via LIN communication. Refer to Front Power Window Motor LH for detailed component location.
13.	Front door lock assembly LH (door switch)	Transmits the door switch signal to the BCM. Refer to Door Lock Assembly for detailed component location.
14.	Front door request switch LH	Transmits the door request switch signal to the Intelligent Key unit. Refer to Door Request Switch for detailed component location.
15.	Rear door lock assembly LH (door switch)	Transmits the door switch signal to the BCM. Refer to Door Lock Assembly for detailed component location.
16.	Rear door request switch LH (if equipped)	Transmits the door request switch signal to the Intelligent Key unit. Refer to Door Request Switch for detailed component location.
17.	Combination meter	Receives the ignition battery saver meter display signal from the BCM via CAN communication. Refer to Combination Meter (full TFT meter) or Combination Meter (7 inch information display) for detailed component location.
18.	Combination switch	Transmits the combination switch signal to the BCM. Refer to System Description.
19.	Push-button ignition switch	Refer to Push-Button Ignition Switch.
20.	Ignition relay-1 [in fuse block (J/B)]	The ignition relay-1 is controlled by the BCM. The ignition relay-1 supplies push-button ignition switch ON power supply or push-button ignition switch ON signal to each ECU and system when the push-button ignition switch is ON. The BCM compares the status of the ignition relay-1 control signal and push-button ignition status judged by the push-button ignition switch. The BCM monitors the ignition relay-1 operating status by the ignition relay-1 feedback signal.
21.	Accessory relay [in fuse block (J/B)]	The accessory relay is controlled by the BCM. The accessory relay supplies accessory power supply or push-button ignition switch ON signal to each ECU when push-button ignition switch is ON. The BCM compares the status of the accessory relay control signal, and the push-button ignition status judged by the push-button ignition switch.
22.	Ignition relay-2 [in fuse block (J/B)]	The ignition relay-2 is controlled by the BCM. The ignition relay-2 supplies push-button ignition switch ON power supply or push-button ignition switch ON signal to each ECU and system when the push-button ignition switch is ON. The BCM compares the status of the ignition relay-2 control signal and push-button ignition status judged by the push-button ignition switch. The BCM monitors the ignition relay-2 operating status by the ignition relay-3 feedback signal.
23.	Brake pedal position switch	The brake pedal position switch detects that the brake pedal is depressed and transmits the signal to the BCM. Refer to Brake Pedal Position Switch for detailed component location.
24.	Stop lamp switch	The stop lamp switch detects that the brake pedal is depressed and transmits the signal to the BCM. Refer to Stop Lamp Switch for detailed component location.

Push-Button Ignition Switch

The push-button ignition switch is installed in the center of the instrument panel.
When the push-button ignition switch is pressed it transmits the status signal to the Intelligent Key unit.

System Nissan Pathfinder 2025

Power Distribution System

System Description

SYSTEM DIAGRAM

Component	Function
Intelligent Key	Operates based on the results of electronic ID verification using two-way communication between the Intelligent Key and the Nissan Pathfinder vehicle (Intelligent Key unit).
Push-button ignition switch	Refer to Push-Button Ignition Switch.
Stop lamp switch	Stop lamp switch detects that brake pedal is depressed, and then transmits ON/OFF signal to BCM.
Brake pedal position switch	Brake pedal position switch detects that brake pedal is depressed, and then transmits ON/OFF signal to BCM.
TCM	Transmits shift position signal and cranking enable signal to BCM via CAN communication.
Electric shift control module	Transmits the P/N position signal to the BCM via CAN communication.
Intelligent Key unit	Transmits push-button ignition switch status signal and remote engine start signal to BCM via CAN communication.
ABS actuator and electric unit (control unit)	Transmits Nissan Pathfinder vehicle speed signal to BCM via CAN communication.
BCM	BCM controls the each relay, judged from each switch status. BCM transmits the push-button ignition switch ON signal to IPDM E/R via CAN communication, judged from each switch status. BCM transmits the meter display signal to combination meter via CAN communication.
Combination meter	Combination meter turns the ignition battery saver operation notice/operation confirmation ON according to the request from BCM via CAN communication.
Ignition relay-1 [Fuse block (J/B)]	Controlled by BCM and turns ON/OFF the battery power supply to each parts.
Ignition relay-2 [Fuse block (J/B)]
Ignition relay-3
Accessory relay [Fuse block (J/B)]
IPDM E/R	IPDM E/R controls the integrated ignition relay, and supplies voltage to the load according to the request from BCM via CAN communication.

Signal transmission function list

Signal name	Input	Output	Description
Stop lamp switch signal	Stop lamp switch	BCM	Transmits the stop lamp switch signal to the BCM.
Brake pedal position switch signal	Brake pedal position switch	BCM	Transmits the brake pedal position switch signal to the BCM.
Push-button ignition switch signal	Push-button ignition switch	Intelligent Key unit	Transmits the push-button ignition switch signal to the Intelligent Key unit.
P/N position signal	Electric shift control module	BCM (CAN)	Transmits the P/N position signal via CAN communication.
Shift position signal	TCM	BCM (CAN)	Transmits the shift position signal via CAN communication.
Cranking enable signal	TCM	BCM (CAN)	Transmits the cranking enable signal via CAN communication.
Remote engine start signal	Intelligent Key unit	BCM (CAN)	Transmits the remote engine start signal via CAN communication.
Push-button ignition switch status signal	Intelligent Key unit	BCM (CAN)	Transmits the push-button ignition switch status signal via CAN communication.
Nissan Pathfinder Vehicle speed signal	ABS actuator and electric unit (control unit)	BCM (CAN)	Transmits the Nissan Pathfinder vehicle speed signal via CAN communication.
Push-button ignition switch ON signal	BCM	IPDM E/R (CAN)	Transmits the push-button ignition switch ON signal via CAN communication.
Meter display signal	BCM	Combination meter (CAN)	Transmits the meter display signal via CAN communication.

SYSTEM DESCRIPTION

The POWER DISTRIBUTION SYSTEM (PDS) is the system that the BCM controls with the operation of the push-button ignition switch and performs the power distribution to each power circuit. This system is used instead of the mechanical power supply changing mechanism with the operation of the conventional key cylinder.

Allocation to the accessory power supply, refer to the auto ACC function. Refer to System Description.
The push-button ignition switch can be operated when the Intelligent Key is in the following conditions:
- Intelligent Key is in the detection area of the inside key antenna.
- Intelligent Key backside is contacted to push-button ignition switch.
Push-button ignition switch operation is an input to the Intelligent Key unit as a signal. The Intelligent Key unit transmits the push-button ignition switch status and remote engine start signal to the BCM via CAN communication. The BCM changes the push-button ignition switch mode according to the status and operates the following relays to supply power to each power circuit:
- Ignition relay (IPDM E/R)
- Ignition relay-1 [Fuse block(J/B)]
- Ignition relay-2 [Fuse block(J/B)]
- Ignition relay-3
- Accessory relay -1 [Fuse block(J/B)]

IGNITION BATTERY SAVER SYSTEM

The ignition battery saver system is a system in which the BCM automatically shuts off the power supply (push-button ignition switch ON -> OFF) to protect the battery.

The BCM activates the ignition battery saver system 10 minutes after the ignition battery saver timer function operating conditions are met. Also, the meter display signal is transmitted to the combination meter via CAN communication as operation notice and operation confirmation, and the information display is operated.

Operating Condition of Ignition Battery Saver Timer Function

When all the following conditions are met for 10 minutes, the battery saver system will cut off the power supply (push-button ignition switch ON -> OFF) to prevent battery discharge:

Push-button ignition switch is ON
Engine stopped

Cancel Condition of Ignition Battery Saver Timer Function

If any of the following conditions are met the battery saver timer function is canceled:

CONSULT

Push-button ignition switch is not ON.
Engine running
Select "Diagnosis (ALL system)" of "BCM"

NOTE:
Ignition battery saver timer function will return 1 minute or more, after closing CONSULT or removing VI from the Nissan Pathfinder vehicle.

Operation Notice Function (7 Minutes have Passed Since the Timer was Activated)

7 minutes after ignition battery saver timer is activated, information display (message display) is activated as and operation notice.

Combination meter (Information display)
Operation	"Power will turn off to save the battery"
Operating time	Approx. 3 minutes

Operation Confirmation Function (10 Minutes have Passed Since the Timer was Activated)

10 minutes after ignition battery saver timer is activated, information display (message display) is activated as and operation confirmation.

Combination meter (Information display)
Operation	"Power turned off to save the battery"
Operating time	Approx. 1 minutes

Temporarily Disabling the Ignition Battery Saver System

The ignition battery saver system can be temporarily disabled, without using CONSULT, to prevent it from functioning when performing trouble diagnosis. Refer to Diagnosis Procedure.

POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON IGNITION SWITCH OPERATION

The power supply position changing operation can be performed with the following operations:

NOTE:

When an Intelligent Key is within the detection area of inside key antenna and when Intelligent Key backside is contacted to push-button ignition switch, it is equivalent to the operations below.

When starting the engine, the BCM monitors under the engine start conditions:

Brake pedal operating condition

Shift selector position

Nissan Pathfinder Vehicle speed

Vehicle speed: less than 2.5 MPH (4 km/h)

Power supply position	Engine start/stop condition		Push-button ignition switch operation frequency
Power supply position	Shift selector position	Brake pedal operation condition	Push-button ignition switch operation frequency
OFF → ACC	—	Not depressed	1
OFF → ACC → ON	—	Not depressed	2
OFF → ACC → ON → OFF	—	Not depressed	3
OFF → START ACC → START ON → START	P or N position	Depressed	1
Engine is running → OFF	—	—	1

Vehicle speed: 2.5 MPH (4 km/h) or more

Power supply position	Engine start/stop condition		Push-button ignition switch operation frequency
Power supply position	Shift selector position	Brake pedal operation condition	Push-button ignition switch operation frequency
Engine is running → ACC	—	—	Emergency stop operation
Engine stall return operation while driving	N position	Not depressed	1

Emergency stop operation

Press and hold the push-button ignition switch for 2 seconds or more.
Press the push-button ignition switch 3 times or more within 1.5 seconds.

Auto Acc Function

System Description

SYSTEM DIAGRAM

Component	Function
Intelligent Key	Operates based on the results of electronic ID verification using two-way communication between the Intelligent Key and the Nissan Pathfinder vehicle (Intelligent Key unit).
Each door request switch	Detects door lock/unlock operation.
Push-button ignition switch	Refer to Push-Button Ignition Switch.
Each door switch	Detects door open/close condition.
Combination switch	Inputs the each switch condition signal to BCM.
Front power window motor LH	Transmits front power window open/close signal to BCM via LIN communication.
Intelligent Key unit	Transmits push-button ignition switch status signal and door lock/unlock request signal to BCM via CAN communication.
ABS actuator and electric unit (control unit)	Transmits Nissan Pathfinder vehicle speed signal to the BCM via CAN communication.
TCU	Transmits auto ACC request signal to BCM via CAN communication.
BCM	BCM operates the auto ACC function based on each signal state.
Accessory relay	Controlled by the BCM and turns ON/OFF the battery power supply to each parts.
Audio/Navigation	Transmits auto ACC request signal to BCM via CAN communication. Auto ACC status signal receives from BCM via CAN communication.

Signal transmission function list

Signal name	Input	Output	Description
Door request switch signal	Each door request switch	Intelligent Key unit	Transmits the door request switch signal to the Intelligent Key unit.
Push-button ignition switch signal	Push-button ignition switch	Intelligent Key unit	Transmits the push-button ignition switch signal to the Intelligent Key unit.
Door switch signal	Each door switch	BCM	Transmits the door switch signal to the BCM.
Combination switch signal	Combination switch	BCM	Transmits the combination switch signal to the BCM.
Front power window open/close signal	Front power window motor LH	BCM (LIN)	Transmits the front power window open/close signal via LIN communication.
Push-button ignition switch status signal	Intelligent Key unit	BCM (CAN)	Transmits the push-button ignition switch status signal via CAN communication.
Door lock/unlock request signal	Intelligent Key unit	BCM (CAN)	Transmits the door lock/unlock request signal via CAN communication.
Auto ACC request signal	Audio/Navigation TCU	BCM (CAN)	Transmits the auto ACC request signal via CAN communication.
Auto ACC status signal	BCM	Audio/Navigation (CAN)	Transmits the auto ACC status signal via CAN communication.
Nissan Pathfinder Vehicle speed signal	ABS actuator and electric unit (control unit)	BCM (CAN)	Transmits the Nissan Pathfinder vehicle speed signal via CAN communication.

SYSTEM DESCRIPTION

In conventional vehicles, power is supplied to the accessories of the vehicle after the push-button ignition switch is placed to ACC.

The AUTO ACC function is a function that bypasses the push-button ignition switch ACC mode and automatically distributes accessory power supply to each switch and unit based on door unlock operation, etc. using the Intelligent Key.

OPERATION FLOW

Push-button ignition switch ON state

In this status the push-button ignition switch is operated and placed ON.

Audio/Navigation use possible state

In this status the audio/navigation, and each switch and unit that is activated by the accessory power supply can be operated.
When 10 minutes pass after conditions are satisfied while audio/navigation are not operated, audio/navigation turns OFF.

Audio/Navigation preparation state

In this status audio/navigation are stopped, but the switches and units other than those for audio/navigation that can operate by using the accessory power supply are available until the accessory power supply turns OFF.
When audio/navigation is operated within 1 minutes after conditions are satisfied, operation time is extended for 10 minutes. Audio/navigation can be operated for a maximum of 30 minutes after the status is satisfied.

Function OFF state

In this status the AUTO ACC function stops and power to the accessories is not supplied.

Function status	Shifting condition	Accessory power supply
Shifting from “Function OFF state” to "Push-button ignition switch ON state"	Any of the following conditions are satisfied: Push-button ignition switch ON from OFF. Operate push-button ignition switch and start the engine. Operate REMOTE ENGINE START button of Intelligent Key and start the engine.	OFF –> ON
Shifting from “Audio/Navigation preparation state” to “Push-button ignition switch ON state”		ON
Shifting from “Audio/Navigation use possible state” to “Push-button ignition switch ON state”		ON
Shifting from “Function OFF state” to “Audio/Navigation preparation state”	Any of the following conditions are satisfied: Each door is opened or closed. Close all doors and back door, and lock all doors with the Intelligent Key or door request switch. Operate either the door request switch or the unlock button of the Intelligent Key to unlock the door. Operate lighting switch and turn ON the tail lamp.	OFF –> ON
Shifting from “Audio/Navigation preparation state” to “Audio/Navigation use possible state”	Operate audio/navigation.	ON
Shifting from “Push-button ignition switch ON state” to “Audio/Navigation use possible state”	Push-button ignition switch OFF from ON while front door LH is closed with Nissan Pathfinder vehicle speed is less than 2 MPH (3 km/h).	ON
Shifting from “Push-button ignition switch ON state” to “Audio/Navigation preparation state”	Push-button ignition switch OFF from ON while front door LH is open with Nissan Pathfinder vehicle speed is less than 2 MPH (3 km/h).	ON
Shifting from “Audio/Navigation use possible state” to “Audio/Navigation preparation state”	Any of the following conditions are satisfied: Front door LH is opened. Close all doors and back door, and lock all doors with the Intelligent Key or door request switch. 10 minutes pass from “Audio/Navigation use possible state”.	ON
Shifting from “Audio/Navigation use possible state” to “Function OFF state”	30 minutes pass from “Audio/Navigation use possible state”.	ON –> OFF
Shifting from “Audio/Navigation preparation state” to “Function OFF state”	1 minutes or 3 minutes pass from “Audio/Navigation preparation state”.	ON –> OFF
Shifting from “Audio/Navigation use possible state” time extension (1 minute)	Any of the following conditions are satisfied: Each door is opened or closed. Close all doors and back door, and lock all doors with the Intelligent Key or door request switch. Operate either the door request switch or the unlock button of the Intelligent Key to unlock the door. Operate lighting switch and turn ON the tail lamp. Operate power window switch and open/close the power window.	ON
Shifting from “Push-button ignition switch ON state” (in status of emergency stop) to “Audio/Navigation use possible state”	Nissan Pathfinder Vehicle speed is less than 2 MPH (3 km/h) and except front door LH is opened.	ON
Shifting from “Push-button ignition switch ON state” (in status of emergency stop) to “Audio/Navigation preparation state”	Nissan Pathfinder Vehicle speed is less than 2 MPH (3 km/h) and front door LH is opened.	ON
Shifting from “Push-button ignition switch ON state” (in status of temporarily disabling the ignition battery saver) to “Audio/Navigation use possible state”	Press and hold the push-button ignition switch continuously for 3 seconds or more when all of the following conditions are satisfied: Selector lever: Except P or N position Brake pedal: Not depressed Front door LH: Close	ON
Shifting from “Push-button ignition switch ON state” (in status of temporarily disabling the ignition battery save) to “Audio/Navigation preparation state”	Press and hold the push-button ignition switch continuously for 3 seconds or more when all of the following conditions are satisfied: Shift selector: Except P or N position Brake pedal: Not depressed Front door LH: Open	ON