Nissan Rogue Service Manual: System

EPS SYSTEM

EPS SYSTEM : System Description

SYSTEM DIAGRAM

INPUT/OUTPUT SIGNAL

Communicates the signal from each control unit via CAN communication.

DESCRIPTION

• EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.
•  In case of an error in the electrical system, the fail-safe function stops output signals to the EPS motor. Refer to STC-8, "EPS SYSTEM : Fail-Safe".
•  EPS control unit decreases the output signal to EPS motor during extreme use of the power steering function (e.g., full steering) for protection of the EPS motor and EPS control unit (Overload protection control).
•  Extensive steering at low speed will cause the EPS control unit and EPS motor to heat up. Once temperature reaches the critical point, the EPS control unit will reduce current to reduce heat up.

  System will recover as temperature lowers (reduced or no assistance).

EPS WARNING LAMP INDICATION

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

CAUTION: EPS warning lamp also turns ON due to data reception error, CAN communication error etc.

EPS SYSTEM : Fail-Safe

• If any malfunction occurs in the system and the control unit detects the malfunction, the EPS warning lamp in the combination meter turns ON to indicate system malfunction.
•  When EPS warning lamp is ON, the system enters into a manual steering state. (turning force at steering wheel becomes heavy.)
•  Under abnormal vehicle speed signal conditions, vehicle speed is judged as constant

EPS SYSTEM : Protection Function

While overload protection control is activated, assist torque gradually decreases and the steering wheel turning force becomes heavy. Assist torque returns to normal if the steering wheel is not turned for a while.