Nissan Quest E52. Instruction — part 1180

SYSTEM

STC-9

< SYSTEM DESCRIPTION >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

When Steering Wheel is Rotated to the Left

The hydraulic routes open from power steering pump to gear housing left side and from gear housing right
side to reservoir tank, providing right direction assist force to the rack.

CONDITIONS FOR HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP ON

• When the hydraulic pump electric power steering system is operating and steering assist force is being gen-

erated, the hydraulic pump electric power steering warning lamp is OFF.

• When the hydraulic pump electric power steering system is stopped by the fail-safe or protective function

and steering assist force is not being generated, the hydraulic pump electric power steering warning lamp
turns ON to inform the driver that the system is in the instruction steering state.
NOTE:
When the hydraulic pump electric power steering system turns ON according to the protection system, the
cause is internal high temperature state of the hydraulic pump electric power steering system. By stopping
the engine, internal temperature of the system decreases. After starting the engine, the system returns to the
normal state and the hydraulic pump electric power steering system warning lamp turns OFF. (The system is
not malfunctioning.) For information about the protective function, refer to

STC-10, "HYDRAULIC PUMP

ELECTRIC POWER STEERING SYSTEM : Protection Function"

.

• When the ignition switch is turned ON, this lamp turns ON for lamp check (system check). When the system

is operating normally, the lamp turns OFF after the engine starts.

HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : Fail-safe

INFOID:0000000009650858

When an error occurs in the hydraulic pump electric power steering system, fail-safe brings the system to a
halt (instruction steering) or restricted (constant steering assist level) state. When the system is in a halt state,
fail-safe turns ON the hydraulic pump electric power steering warning lamp to warn the driver that the hydrau-
lic pump electric power steering system is in the manual steering state.

JSGIA0917GB

Condition

Hydraulic pump electric 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

DTC

Fail-safe condition

C1143

Certain steering assist force

C1601

Instruction steering state

C1602

Certain steering assist force

C1606

Instruction steering state

C1607

Certain steering assist force

STC-10

< SYSTEM DESCRIPTION >

SYSTEM

HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : Protection Function

INFOID:0000000009650859

• When the steering wheel is operated repeatedly or turned all the way for a long period during parking or low

speed driving, the function of the hydraulic pump electric power steering system becomes limited to prevent
the system from overheating. If the steering wheel is operated further more, the hydraulic pump electric
power steering system stops and the hydraulic pump electric power steering system warning lamp may be
turned ON. In this case, the steering wheel operation temporarily becomes hard. This is not a malfunction.
When the engine is turned OFF (ignition switch OFF) and steering operation is stopped for a while, the tem-
perature of the hydraulic pump electric power steering system decreases and the steering operation returns
to normal after restarting the engine.

• Then, the hydraulic pump electric power steering system warning lamp turns OFF. If the system is OFF

under the protection state, the hydraulic pump electric power steering system warning lamp turns ON to
warn that the system is in the instruction steering state. (This is not a system malfunction.) In addition, the fol-
lowing DTC remains to distinguish from malfunction.

C1608

Instruction steering state

U1000

Normal control
NOTE:
If the cause is in a different ECU, the state changes to fixed steering assist force.

DTC

Fail-safe condition

DTC

vehicle condition

C160A

The system temporarily enters the instruction steering state. (This is not a hydraulic pump electric
power steering system malfunction.)

DIAGNOSIS SYSTEM (POWER STEERING CONTROL MODULE)

STC-11

< SYSTEM DESCRIPTION >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

DIAGNOSIS SYSTEM (POWER STEERING CONTROL MODULE)

CONSULT Function

INFOID:0000000009650860

FUNCTION

CONSULT can display each diagnostic item using the diagnostic test modes shown as per the following.

*

: The following diagnosis information is erased by erasing.

ECU IDENTIFICATION

Displays the part number stored in the control unit.

SELF-DIAG RESULTS MODE

Refer to

STC-14, "DTC Index"

.

When “CRNT” is displayed on self-diagnosis result.

• The system is presently malfunctioning.

When “PAST” is displayed on self-diagnosis result.

• System malfunction in the past is detected, but the system is presently normal.

DATA MONITOR MODE

NOTE:
The following table includes information (items) inapplicable to this vehicle. For information (items) applicable
to this vehicle, refer to CONSULT display items.

Diagnostic test mode

Function

ECU identification

The part number stored in the control unit can be read.

Self Diagnostic Results

Self-diagnostic results and freeze frame data can be read and erased quickly*

Data monitor

Input/Output data in the power steering control module can be read.

Monitor item (Unit)

Remarks

BATTERY VOLT (V)

Displays the power supply voltage for power steering control module.

STR ANG SPD (deg/s)

Displays the steering angle speed based on the steering angle signal transmitted by
CAN communications.

MOTOR CURRENT (A)

Displays the current value consumed by power steering control module.

MTR REV SPD COMM (rpm)

Displays the power steering motor speed command value.

MTR REV SPD (rpm)

Displays the power steering motor speed.

C/U TEMP (

°

C or

°

F)

Displays the temperature of the power steering control module.

C/U TEMP A (

°

C or

°

F)

Displays the temperature of the power steering control module.

MTR ASSIST (%)

Displays the current percentage of the allowable assist ratio power steering motor.

ESTM VHCL SPD (km/h or mph)

Displays the vehicle speed calculated by the power steering control module.

WARNING LAMP (On/Off)

Hydraulic pump electric power steering system warning lamp control status is displayed.

ENGINE STATUS (STOP/RUN/CRANK)

Engine speed is displayed from engine condition signal with CAN communication

VHCL SPD JUDGE (OK/NG)

Displays the receiving status of the vehicle speed signal transmitted by CAN communi-
cations.

STC-12

< ECU DIAGNOSIS INFORMATION >

POWER STEERING CONTROL MODULE

ECU DIAGNOSIS INFORMATION

POWER STEERING CONTROL MODULE

Reference Value

INFOID:0000000009650861

VALUES ON THE DIAGNOSIS TOOL

NOTE:
The following table includes information (items) inapplicable to this vehicle. For information (items) applicable
to this vehicle, refer to CONSULT display items.

*1: The value changes according to load of power steering motor.
*2: This is in close agreement with a motor speed command value. Although a quick steering operation may
cause disagreement, this is not a malfunction.
*3: Usually, 100% is displayed. An excessive steering operation gradually lowers the percentage. When left
standing, the percentage returns to 100%.

Monitor item

Data monitor

Condition

Display value

BATTERY VOLT

Engine running

Battery voltage (V)

STR ANG SPD

The steering wheel is not steered.

Approx. 0.0 deg/s

The steering wheel is steered.

Displays steering angle speed (deg/s)

MOTOR CURRENT

Engine running

Steering wheel: Not steering (There is
no steering force)

MAX approx. 10 A

*1

Steering wheel: Right or left turn

Displays consumption current of pow-
er steering control module (A)

MTR REV SPD COMM

Engine running

Steering wheel: Not steering (There is
no steering force)

Shows an almost constant value
(rpm)

Steering wheel: Right or left turn

The value changes as a steering
speed (rpm)

MTR REV SPD

Engine running

Steering wheel: Not steering (There is
no steering force)

Shows an almost constant value

(rpm)

*2

Steering wheel: Right or left turn

The value changes as a steering

speed (rpm)

*2

C/U TEMP

Engine running

Displays temperature of inside of
power steering control module (

°

C or

°

F)

C/U TEMP A

Engine running

Displays temperature of inside of
power steering control module (

°

C or

°

F)

MTR ASSIST

Engine running

100%

*3

ESTM VHCL SPD

Vehicle stopped

0.00 km/h or mph

While driving

Approximately equal to the indication

on speedometer

*4

(inside of

±

10%)

WARNING LAMP

Hydraulic pump electric power steering warning lamp: ON

On

Hydraulic pump electric power steering warning lamp: OFF

Off

ENGINE STATUS

Engine not running

STOP

Engine running

RUN

Engine cranking

CRANK

VHCL SPD JUDGE

Vehicle speed signal can be received via CAN communication

OK

Vehicle speed signal cannot be received via CAN communica-
tion

NG