Nissan X-Trail 32. Manual - part 1990

STC-10

< SYSTEM DESCRIPTION >

COMPONENT PARTS

*1: With stop/start system
*2: Models around view monitor with park assist

EPS Control Unit

INFOID:0000000010688400

NOTE:
The EPS control unit, EPS motor, torque sensor, and reduction gear are integrated with the steering column
assy.
• EPS control unit 

 is installed to steering column assembly.

• 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 con-
dition.

• 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).

• When the stop/start system operation starts, the EPS control unit

receives a stop/start status signal from ECM via CAN communica-
tion and disables the assist control. (Models with stop/start system)

• When the driver turns the steering wheel (torque application exceeding the specified torque) during stop/

start system operation, the EPS control unit transmits an EPS torque signal to ECM via CAN communication
and restarts the engine (disables stop/start system). (Models with stop/start system)

• EPS control unit receives a Park Assist status signal from the around view monitor control unit and performs

around view monitor with park assist control.

• EPS control unit receives a Park Assist status signal to the around view monitor control unit to examine

whether the EPS control unit can perform around view monitor with park assist control or not.

• Around view monitor with park assist control is cancelled when the driver operates the steering wheel during

around view monitor with park assist control.

• Diagnoses can be performed with CONSULT.

EPS Motor, Torque Sensor, Reduction Gear

INFOID:0000000010688401

NOTE:
The EPS control unit, EPS motor, torque sensor, and reduction gear are integrated with the steering column
assy.

Around view monitor control unit

*2

• Transmits mainly the following signal to EPS control unit via 

CAN communication. 

- Park Assist status signal
- Park Assist malfunction signal
- Steering angle command signal
• Receives mainly the following signal to EPS control unit via 

CAN communication.

- EPS torque signal
- Park Assist permit signal
• For detailed installation location, refer to 

AV-76, "Around View 

Monitor Control Unit"

.

Sonar control unit

*2

• Transmits mainly the following signals to EPS control unit via 

CAN communication. 

- Steering angle command signal
• For detailed installation location,

: Refer to 

SN-119, "Component Parts Location"

.

EPS control unit

STC-10, "EPS Control Unit"

EPS motor

STC-10, "EPS Motor, Torque Sensor, Reduction Gear"

Torque sensor

STC-10, "EPS Motor, Torque Sensor, Reduction Gear"

Reduction gear

STC-10, "EPS Motor, Torque Sensor, Reduction Gear"

No.

Component

Function

JSGIA1430ZZ

COMPONENT PARTS

STC-11

< SYSTEM DESCRIPTION >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

EPS motor 

, torque sensor 

 and reduction gear 

 are installed

to steering column assembly.

EPS MOTOR

EPS motor provides the assist torque by the control signal from EPS control unit.

TORQUE SENSOR

Torque sensor detects the steering torque, and transmits the signal to EPS control unit.

REDUCTION GEAR

Reduction gear increases the assist torque provided from EPS motor with worm gears, and outputs to the col-
umn shaft.

JSGIA1431ZZ

STC-12

< SYSTEM DESCRIPTION >

SYSTEM

SYSTEM

EPS SYSTEM

EPS SYSTEM : System Description

INFOID:0000000010688402

DESCRIPTION

• EPS system consists mainly of EPS system, EPS motor, torque

sensor, and reduction gear.

• 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), around view monitor control unit, 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, vehicle speed signal, etc. Then it generates an optimum
assist torque signal to the EPS motor according to the driving con-
dition.

• When the driver turns the steering wheel (torque application

exceeding the specified torque) during stop/start, the EPS control
unit restarts the engine (disables stop/start system) and immedi-
ately brings the assist control in its ready-to-start state.

• If EPS becomes out of order, the power steering warning lamp

blinks and the Stop/Start System brings about such conditions as
follows (Models with stop/start system):

- Stop/start mode is not enabled under non stop/start state.
- The engine is restarted during stop/start, regardless of steering

wheel operation. (Models with stop/start system)

• The around view monitor with park assist function assists garaging

and parallel parking and allows automatic operation of the steering
wheel when the system starts.

• When an error in the electrical system, the fail-safe function stops output signals to the EPS motor. Refer to

STC-14, "EPS SYSTEM : Fail-Safe"

.

• EPS control unit decreases the output signal to EPS motor while extremely using the power steering func-

tion (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection
control). Refer to 

STC-20, "Protection Function"

.

SYSTEM DIAGRAM

NOTE:

JSGIA1102GB

SYSTEM

STC-13

< SYSTEM DESCRIPTION >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

Around view monitor control unit and sonar control unit: Models around view monitor with park assist

INPUT/OUTPUT SIGNAL

Communicates the signal from each control unit via CAN communication. 

*1: With stop/start system
*2: Models around view monitor with park assist

ELECTRIC POWER STEERING WARNING LAMP INDICATION

• Turn 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).

JSGIA1557GB

Control unit

Signal status

ECM

• Transmits mainly the following signals to EPS control unit via CAN communication. 
- Engine status signal 

- EPS assist request signal 

*1

- Stop/start status signal 

*1

• Receives mainly the following signal to EPS control unit via CAN communication.
- EPS operation signal 

- Stop/start inhibit signal

*1

ABS actuator and electric unit (con-
trol unit)

• Transmits the following signal to EPS control unit via CAN communication. 
- Vehicle speed signal (ABS)

Combination meter

• Transmits the following signal to EPS control unit via CAN communication. 
- Vehicle speed signal (Meter)
• Receives the following signal from EPS control unit via CAN communication. 
- Electric power steering warning lamp

Around view monitor control unit

*2

• Transmits mainly the following signal to EPS control unit via CAN communication. 
- Park Assist status signal
- Park Assist malfunction signal
- Steering angle command signal
• Receives mainly the following signal to EPS control unit via CAN communication.
- EPS torque signal
- Park Assist permit signal

Sonar control unit

*2

• Transmits the following signal to EPS control unit via CAN communication. 
- Steering angle command signal