Nissan Pathfinder: Steering Control System - System

Nissan Pathfinder (R53) 2022-2025 Service Manual / Steering :: Steering Control System / System Description / System

Eps System Nissan Pathfinder 2022

EPS system consists mainly of EPS control unit, EPS motor, torque sensor.
EPS system calculates a control signal to transmit to the EPS motor based on information received from ECM, ABS actuator and electric unit (control unit), steering angle sensor, chassis control module, and combination meter via CAN communication and information received from torque sensor.
EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, Nissan Pathfinder vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.
After engine start, the EPS system performs control.
When a malfunction occurs in the system, the fail-safe function stops the EPS system (manual steering state) or restricts its operation (Constant steering assist level state). Refer to Fail-safe.
EPS control unit decreases the output signal to EPS motor while extremely using the power steering function (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection control). Refer to Protection Function.

SYSTEM DIAGRAM

INPUT SIGNAL AND OUTPUT SIGNAL

Component parts	Signal description
ECM	Transmits the following signals to the EPS control unit via CAN communication: Engine status signal EPS assist request signal Stop/start status signal Receives the battery supply current signal from the EPS control unit via CAN communication.
Steering angle sensor	Transmits the steering angle sensor signal to the EPS control unit via CAN communication.
Chassis control module	Transmits the drive mode signal to the EPS control unit via CAN communication.
ABS actuator and electric unit (control unit)	Transmits the Nissan Pathfinder vehicle speed signal to the EPS control unit via CAN communication.
Combination meter	Transmits the Nissan Pathfinder vehicle speed signal to the EPS control unit via CAN communication. Receives the power steering warning lamp signal from the EPS control unit via CAN communication.
Torque sensor	Transmits the steering torque sensor signal to the EPS control unit.
EPS motor	Receives the motor control signal from the EPS control unit.
ADAS (Advanced Driver Assistance Systems) control unit 2	Transmits the steering status signal to the EPS control unit via CAN communication. Receives the steering status signal from the EPS control unit via CAN communication.
BCM (Body Control Module)	Transmits the drive mode switch signal to the EPS control unit via CAN communication.

CONDITIONS FOR POWER STEERING WARNING LAMP ON

Turns ON when there is a malfunction in EPS system. If indicates that fail-safe mode is engaged and enters a manual steering state (Control turning force steering wheel becomes heavy).
Also turns ON when ignition switch ON, for purpose of lamp check. Turns OFF after the engine starts, if system is normal.

Condition	Power steering warning lamp
Ignition switch ON. (Lamp check)	ON
After engine start (steering assist force is generated)	OFF
When steering assist is stopped	ON

Name	Design	Layout/Function
Power steering warning lamp		For layout, refer to Design (full TFT meter).
		For layout, refer to Design (7 inch information display meter).
		For function, refer to System Description.