STEERING

STC
A

B
SECTION
STEERING CONTROL SYSTEM C

E
CONTENTS
PRECAUTION ............................................... 3 HYDRAULIC PUMP ELECTRIC POWER F
STEERING SYSTEM ......................................... 14
PRECAUTIONS ................................................... 3 Wiring Diagram ........................................................14
Precaution for Supplemental Restraint System STC
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN- BASIC INSPECTION ................................... 18
SIONER" ................................................................... 3
Service Notice and Precautions for Hydraulic DIAGNOSIS AND REPAIR WORK FLOW ....... 18
Work Flow ................................................................18 H
Pump Electric Power Steering System ..................... 3
Diagnostic Work Sheet ............................................19
SYSTEM DESCRIPTION .............................. 4
DTC/CIRCUIT DIAGNOSIS ......................... 21 I
COMPONENT PARTS ........................................ 4
Component Parts Location ........................................ 4 C1143 STEERING ANGLE SENSOR ............... 21
Component Description ............................................. 4 DTC Logic ................................................................21
Power Steering Oil Pump Assembly ......................... 5 Diagnosis Procedure ...............................................21 J

SYSTEM .............................................................. 6 C1601 BATTERY POWER SUPPLY ................ 22

DTC Logic ................................................................22 K
HYDRAULIC PUMP ELECTRIC POWER STEER- Diagnosis Procedure ...............................................22
ING SYSTEM ............................................................... 6
HYDRAULIC PUMP ELECTRIC POWER C1606 EPS MOTOR .......................................... 25
STEERING SYSTEM : System Description .............. 6 DTC Logic ................................................................25 L
HYDRAULIC PUMP ELECTRIC POWER Diagnosis Procedure ...............................................25
STEERING SYSTEM : Fail-safe ............................... 8
HYDRAULIC PUMP ELECTRIC POWER C1607, C1608 POWER STEERING CON-
M
STEERING SYSTEM : Protection Function .............. 9 TROL MODULE ................................................ 26
DTC Logic ................................................................26
DIAGNOSIS SYSTEM (POWER STEERING Diagnosis Procedure ...............................................26
CONTROL MODULE) ........................................10 N
CONSULT Function ................................................ 10 C160A HEAT PROTECTION ............................ 27
DTC Logic ................................................................27
ECU DIAGNOSIS INFORMATION .............. 11 O
U1000 CAN COMM CIRCUIT ........................... 28
POWER STEERING CONTROL MODULE ........11 Description ...............................................................28
Reference Value ..................................................... 11 DTC Logic ................................................................28
Fail-safe .................................................................. 12 Diagnosis Procedure ...............................................28 P
Protection Function ................................................. 12
DTC Inspection Priority Chart ................................. 13
HYDRAULIC PUMP ELECTRIC POWER
DTC Index ............................................................... 13 STEERING WARNING LAMP ........................... 29
Component Function Check ....................................29
WIRING DIAGRAM ...................................... 14 Diagnosis Procedure ...............................................29

SYMPTOM DIAGNOSIS .............................. 30

Revision: May 2013 STC-1 2014 Pathfinder

HYDRAULIC PUMP ELECTRIC POWER UNBALANCE STEERING WHEEL TURNING
STEERING WARNING LAMP DOES NOT FORCE AND RETURN BETWEEN RIGHT
TURN ON ........................................................... 30 AND LEFT ......................................................... 34
Description .............................................................. 30 Diagnosis Procedure ............................................... 34
Diagnosis Procedure .............................................. 30
UNBALANCE STEERING WHEEL TURNING
HYDRAULIC PUMP ELECTRIC POWER FORCE (TORQUE VARIATION) ....................... 35
STEERING WARNING LAMP DOES NOT Diagnosis Procedure ............................................... 35
TURN OFF ......................................................... 31
Description .............................................................. 31 REMOVAL AND INSTALLATION .............. 37
Diagnosis Procedure .............................................. 31
POWER STEERING CONTROL MODULE ....... 37
STEERING WHEEL TURNING FORCE IS Removal and Installation ......................................... 37
HEAVY OR LIGHT ............................................. 32
Diagnosis Procedure .............................................. 32

Revision: May 2013 STC-2 2014 Pathfinder

 PRECAUTIONS
< PRECAUTION >
PRECAUTION A
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT B
PRE-TENSIONER" INFOID:0000000009177121

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along C
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. Information necessary to service the system safely is included in the SR and SB section of
this Service Manual.
WARNING: D
• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer. E
• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
F
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
STC
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni- H
tion ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the I
battery and wait at least three minutes before performing any service.
Service Notice and Precautions for Hydraulic Pump Electric Power Steering System
INFOID:0000000009177122
J

• Check each tire for proper air pressure and size. Refer to WT-65, "Tire Air Pressure".
• Verify that the steering system components are genuine NISSAN parts and have been installed properly.
K
• Check the steering column for loose mounting bolts.
• Check the steering gear assembly for loose mounting bolts. Check the inner sockets and outer sockets for
damage or wear. Inspect the boots and seals for leakage of power steering fluid.
• Verify proper wheel alignment. Refer to FSU-5, "Inspection and Adjustment". L
• Check for any damage, wear, or modification to the suspension and body that would result in increased
weight or an improper wheelarch height. Refer to FSU-20, "Wheelarch Height".
• Check for proper battery voltage. M
• Verify that all power steering pump assembly connections are clean and fully seated.
• Verify that only genuine NISSAN E-PSF is used. Use of any power steering fluid other than genuine NISSAN
E-PSF will prevent the power steering system from proper operation.
• An audible high pitch noise may be heard from the engine compartment when the steering wheel is oper- N
ated, particularly at low speeds such as a parking lot maneuver. This condition is not a malfunction, rather
normal system operation. Steering at low speeds or parking lot maneuvers demands higher hydraulic assis-
tance, resulting in larger power steering pump load and increased system noise. O
• The power steering pump is electrically controlled by the power steering control module.
• Before connecting or disconnecting the power steering control module harness connectors, turn ignition
switch “OFF” and disconnect battery ground cable. Battery voltage is applied to power steering control mod-
ule even if ignition switch is turned “OFF”. P

Revision: May 2013 STC-3 2014 Pathfinder

 COMPONENT PARTS
< SYSTEM DESCRIPTION >
SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts Location INFOID:0000000009177123

ALGIA0104ZZ

1. Power steering oil pump assembly 2. Steering angle sensor 3. ECM

(view from the right side of the engine (view with the steering wheel re- (view from the left side of the engine
compartment) moved) compartment)
4. Combination meter

Component Description INFOID:0000000009177124

Component parts Reference

Power steering oil pump assembly STC-5, "Power Steering Oil Pump Assembly"
Transmits steering angle sensor signal to the power steering control module via CAN commu-
Steering angle sensor
nication.
ECM Transmits engine speed signal to the power steering control module via CAN communication.
Combination meter Transmits vehicle speed signal to the power steering control module via CAN communication.

Revision: May 2013 STC-4 2014 Pathfinder

 COMPONENT PARTS
< SYSTEM DESCRIPTION >
Power Steering Oil Pump Assembly INFOID:0000000009177125

A
The power steering oil pump assembly is primarily composed of the
reservoir tank (1), power steering oil pump (2), power steering motor
(3), and power steering control module (4). B

D
JSGIA0914ZZ

RESERVOIR TANK
Fluid is filled from the reservoir tank. E

POWER STEERING OIL PUMP

The power steering oil pump is driven by the power steering motor and generates hydraulic oil pressure in the
F
system.
POWER STEERING MOTOR
The power steering motor is controlled by the power steering control module and drives the power steering oil STC
pump.
POWER STEERING CONTROL MODULE
By receiving steering angle sensor signal and vehicle speed signal, the power steering control module calcu- H
lates hydraulic pressure of the hydraulic pump electric power steering system according to the driving condi-
tions. The power steering control module controls the power steering motor.
I

Revision: May 2013 STC-5 2014 Pathfinder

 SYSTEM
< SYSTEM DESCRIPTION >
SYSTEM
HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : System Description
INFOID:0000000009177126

• The system is composed primarily of the power steering oil pump assembly (power steering control module,
power steering motor, power steering oil pump, and reservoir tank), hydraulic pipes, and steering gear
assembly.
• The power steering control module controls the speed of the power steering motor according to the vehicle
speed and steering angle speed. By changing the power steering oil pump flow, the power steering control
module controls the steering assist force.
• According to the power steering motor control, the system hydraulic pressure is transmitted from the power
steering motor to power steering oil pump. The power steering oil pump is driven by the system hydraulic
pressure.
• After engine start, the hydraulic pump electric power steering system performs control.
• When a malfunction occurs in the system, the fail-safe function stops the hydraulic pump electric power
steering system (manual steering state) or restricts its operation (certain steering assist force). Refer to STC-
8, "HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : Fail-safe".
• When the power steering function is used continuously in an extreme manner, the protective function
reduces the output to the power steering motor. Refer to STC-9, "HYDRAULIC PUMP ELECTRIC POWER
STEERING SYSTEM : Protection Function".
SYSTEM DIAGRAM

ALGIA0127GB

INPUT/OUTPUT SIGNAL
Communicates the signal from each control unit via CAN communication.

Control unit Signal status

ECM Transmits engine status signal to power steering control module via CAN communication.
Transmits steering angle sensor signal to power steering control module via CAN commu-
Steering angle sensor
nication.
Transmits vehicle speed signal to power steering control module via CAN communication.
Combination meter Receives hydraulic pump electric power steering warning lamp signal from power steering
control module via CAN communication.

OPERATION CHARACTERISTICS

Revision: May 2013 STC-6 2014 Pathfinder

 SYSTEM
< SYSTEM DESCRIPTION >
When the steering angle speed is high or the vehicle speed is low,
force is generated by increasing discharge amount from the power A
steering oil pump and by raising system hydraulic pressure.

JSGIA0916GB

D
OPERATION PRINCIPLE
When Steering Wheel is in the Neutral Position
E

STC

J
JSGIA0918GB

Because the hydraulic routes open at the power steering pump, gear housing right side, gear housing left side,
and reservoir tank, the hydraulic pressure applied to the right side and left side of the gear housing is equal
and no steering assist force is generated. K

When Steering Wheel is Rotated to the Right

L

JSGIA0919GB

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

Revision: May 2013 STC-7 2014 Pathfinder

 SYSTEM
< SYSTEM DESCRIPTION >
When Steering Wheel is Rotated to the Left

JSGIA0917GB

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 manual steering state.
NOTE:
When the hydraulic pump electric power steering system warning lamp 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-9, "HYDRAU-
LIC 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.

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

HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : Fail-safe INFOID:0000000009177127

When an error occurs in the hydraulic pump electric power steering system, fail-safe brings the system to a
halt (manual 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.

DTC Fail-safe condition

C1143 Certain steering assist force
C1601 Manual steering state
C1606 Manual steering state
C1607 Certain steering assist force

Revision: May 2013 STC-8 2014 Pathfinder

 SYSTEM
< SYSTEM DESCRIPTION >
DTC Fail-safe condition
A
C1608 Manual steering state
Normal control
U1000 NOTE:
If the cause is in a different ECU, the state changes to fixed steering assist force. B

HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM : Protection Function

INFOID:0000000009177128
C
• 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. Continued operation of the steering wheel will cause the hydraulic pump elec- D
tric power steering system to stop and the hydraulic pump electric power steering system warning lamp may
come 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 E
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 F
warn that the system is in the manual steering state. (This is not a system malfunction.) In addition, the fol-
lowing DTC remains to distinguish from malfunction.
STC
DTC vehicle condition
The system temporarily enters the manual steering state. (This is not a hydraulic pump electric
C160A
power steering system malfunction.)
H

Revision: May 2013 STC-9 2014 Pathfinder

 DIAGNOSIS SYSTEM (POWER STEERING CONTROL MODULE)
< SYSTEM DESCRIPTION >
DIAGNOSIS SYSTEM (POWER STEERING CONTROL MODULE)
CONSULT Function INFOID:0000000009177129

CAUTION:
After disconnecting the CONSULT vehicle interface (VI) from the data link connector, the ignition must
be cycled OFF → ON (for at least 5 seconds) → OFF. If this step is not performed, the BCM may not go
to "sleep mode", potentially causing a discharged battery and a no-start condition.
FUNCTION
CONSULT can display each diagnostic item using the diagnostic test modes shown as per the following.

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.

ECU IDENTIFICATION
Displays the part number stored in the control unit.
SELF-DIAG RESULTS MODE
Refer to STC-13, "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

Monitor item (Unit) Remarks

BATTERY VOLT (V) Displays the power supply voltage for power steering control module.
Displays the steering angle speed based on the steering angle signal transmitted by
STR ANG SPD (deg/s)
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
Displays the receiving status of the vehicle speed signal transmitted by CAN communi-
VHCL SPD JUDGE (OK/NG)
cations.

Revision: May 2013 STC-10 2014 Pathfinder

 POWER STEERING CONTROL MODULE
< ECU DIAGNOSIS INFORMATION >
ECU DIAGNOSIS INFORMATION A
POWER STEERING CONTROL MODULE
Reference Value INFOID:0000000009177130
B

VALUES ON THE DIAGNOSIS TOOL

C
Data monitor
Monitor item
Condition Display value
BATTERY VOLT Engine running Battery voltage (V) D
The steering wheel is not steered. Approx. 0.0 deg/s
STR ANG SPD
The steering wheel is steered. Displays steering angle speed (deg/s)
E
Steering wheel: Not steering (There is
no steering force) MAX approx. 10 A*1
MOTOR CURRENT Engine running
Displays consumption current of pow-
Steering wheel: Right or left turn F
er steering control module (A)
Steering wheel: Not steering (There is Shows an almost constant value
no steering force) (rpm)
MTR REV SPD COMM Engine running STC
The value changes as a steering
Steering wheel: Right or left turn
speed (rpm)
Steering wheel: Not steering (There is Shows an almost constant value
no steering force) (rpm)*2
H
MTR REV SPD Engine running
The value changes as a steering
Steering wheel: Right or left turn
speed (rpm)*2
I
Displays temperature of inside of
C/U TEMP Engine running power steering control module (°C or
°F)
J
Displays temperature of inside of
C/U TEMP A Engine running power steering control module (°C or
°F)
MTR ASSIST Engine running 100%*3 K
Vehicle stopped 0.00 km/h or mph

ESTM VHCL SPD Approximately equal to the indication L

While driving on speedometer*4
(inside of ±10%)
Hydraulic pump electric power steering warning lamp: ON On
WARNING LAMP M
Hydraulic pump electric power steering warning lamp: OFF Off
Engine not running STOP
ENGINE STATUS Engine running RUN N
Engine cranking CRANK
Vehicle speed signal can be received via CAN communication OK
O
VHCL SPD JUDGE Vehicle speed signal cannot be received via CAN communica-
NG
tion
*1: The value changes according to load of power steering motor. P
*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%.
*4: This may not agree with the speedometer indication immediately after the ignition switch is turned ON. This
is not a malfunction.

Revision: May 2013 STC-11 2014 Pathfinder

 POWER STEERING CONTROL MODULE
< ECU DIAGNOSIS INFORMATION >
TERMINAL LAYOUT

JSGIA0835ZZ

PHYSICAL VALUES

Terminal No.
Description Value
(Wire Color) Condition
(Approx.)
+ − Signal name Input/Output
1
Ground Battery power supply Input Always Battery voltage
(W)
2
Ground Ground — Always 0V
(W)

5 Ignition switch: ON Battery voltage

Ground Ignition power supply Input
(BR) Ignition switch: OFF 0V
7
— CAN-L Input/Output — —
(P)
8
— CAN-H Input/Output — —
(L)

Fail-safe INFOID:0000000009177131

When an error occurs in the hydraulic pump electric power steering system, fail-safe brings the system to a
halt (manual 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.

DTC Fail-safe condition

C1143 Certain steering assist force
C1601 Manual steering state
C1606 Manual steering state
C1607 Certain steering assist force
C1608 Manual steering state
Normal control
U1000 NOTE:
If the cause is in a different ECU, the state changes to fixed steering assist force.

Protection Function INFOID:0000000009177132

• 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

Revision: May 2013 STC-12 2014 Pathfinder

 POWER STEERING CONTROL MODULE
< ECU DIAGNOSIS INFORMATION >
warn that the system is in the manual steering state. (This is not a system malfunction.) In addition, the fol-
lowing DTC remains to distinguish from malfunction. A

DTC vehicle condition

C160A
The system temporarily enters the manual steering state. (This is not a hydraulic pump electric B
power steering system malfunction.)

DTC Inspection Priority Chart INFOID:0000000009177133

C
When multiple DTCs are detected simultaneously, check one by one depending on the following priority list.

Priority Priority order item (DTC) D

• C1601 BATTERY VOLT
1 • C1606 EPS MOTOR
• C1608 CONTROL UNIT E
2 • C1607 EEPROM
3 • C160A HEAT PROTECTION
• C1143 ST ANG SEN CIRCUIT F
4
• U1000 CAN COMM CIRCUIT

DTC Index INFOID:0000000009177134

STC

DTC Items (CONSULT screen terms) Reference

H
C1143 ST ANG SEN CIRCUIT STC-21, "DTC Logic"
C1601 BATTERY VOLT STC-22, "DTC Logic"
C1606 EPS MOTOR STC-25, "DTC Logic" I
C1607 EEPROM STC-26, "DTC Logic"
C1608 CONTROL UNIT STC-26, "DTC Logic"
C160A HEAT PROTECTION STC-27, "DTC Logic"
J
U1000 CAN COMM CIRCUIT STC-28, "DTC Logic"
NOTE: K
If two or more DTCs are detected, refer to STC-13, "DTC Inspection Priority Chart".

Revision: May 2013 STC-13 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
< WIRING DIAGRAM >
WIRING DIAGRAM
HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
Wiring Diagram INFOID:0000000009177135

ABGWA0056GB

Revision: May 2013 STC-14 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
< WIRING DIAGRAM >

STC

AAGIA0035GB

Revision: May 2013 STC-15 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
< WIRING DIAGRAM >

AAGIA0036GB

Revision: May 2013 STC-16 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING SYSTEM
< WIRING DIAGRAM >

STC

AAGIA0037GB

Revision: May 2013 STC-17 2014 Pathfinder

 DIAGNOSIS AND REPAIR WORK FLOW
< BASIC INSPECTION >
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORK FLOW
Work Flow INFOID:0000000009177136

DETAILED FLOW
1.INTERVIEW FROM THE CUSTOMER
Clarify customer complaints before inspection. First of all, perform an interview utilizing STC-19, "Diagnostic
Work Sheet" and reproduce symptoms to understand them fully. Ask customer about his/her complaints care-
fully. Check symptoms by driving vehicle with customer, if necessary.
CAUTION:
Customers are not professional. Never make assumptions like “maybe the customer means that...,” or
“maybe the customer mentioned this symptom”.

>> GO TO 2.
2.CHECK SYMPTOM
Reproduce the symptom that is indicated by the customer, based on the information from the customer
obtained by interview. Also check that the symptom is not caused by protection function. Refer to STC-12,
"Protection Function".
CAUTION:
When the symptom is caused by normal operation, fully inspect each portion and obtain the under-
standing of customer that the symptom is not caused by a malfunction.

>> GO TO 3.
3.CHECK VEHICLE CONDITION
With CONSULT
1. Turn ignition switch ON.
2. Check “C/U TEMP“ and “C/U TEMP A“ in “DATA MONITOR“ of “EPS“.

Monitor item Values

C/U TEMP 90°C (194°F) or less
C/U TEMP A 90°C (194°F) or less
Is the inspection result normal?
YES >> GO TO 4.
NO >> Wait with the ignition switch OFF until the data monitor indication becomes 90 °C (194 °F) or less.
Go to 4 after the temperature drops to 90 °C (194 °F) or less.
4.PERFORM SELF-DIAGNOSIS
With CONSULT
Perform self-diagnosis.
Is any DTC detected?
YES >> Record or print DTC and freeze frame data (FFD). GO TO 5.
NO >> GO TO 7.
5.RECHECK SYMPTOM
With CONSULT
1. Erase self-diagnostic results for “EPS”.
2. Perform DTC confirmation procedures for the malfunctioning system.
NOTE:
If some DTCs are detected at the same time, determine the order for performing the diagnosis based on STC-
13, "DTC Inspection Priority Chart".
Is any DTC detected?

Revision: May 2013 STC-18 2014 Pathfinder

 DIAGNOSIS AND REPAIR WORK FLOW
< BASIC INSPECTION >
YES >> GO TO 6.
NO >> Check harness and connectors based on the information obtained by interview. A
6.REPAIR OR REPLACE THE MALFUNCTIONING COMPONENTS.
• Repair or replace the malfunctioning components.
B
• Reconnect part or connector after repairing or replacing.
• When DTC is detected, erase self-diagnostic results for “EPS”.

C
>> GO TO 8.
7.IDENTIFY THE MALFUNCTIONING SYSTEM BY SYMPTOM DIAGNOSIS
Estimate the malfunctioning system based on symptom diagnosis and perform inspection. D
Can the malfunctioning system be identified?
YES >> GO TO 8.
NO >> Check harness and connectors based on the information obtained by interview. E
8.FINAL CHECK
With CONSULT F
1. Check the reference value for power steering control module.
2. Recheck the symptom and check that symptom is not reproduced on the same conditions.
Is the symptom reproduced? STC
YES >> GO TO 3.
NO >> Inspection End.
Diagnostic Work Sheet INFOID:0000000009177137 H

Description
• In general, customers have their own criteria for a problem. Therefore, it is important to understand the I
symptom and status well enough by asking the customer about his/her concerns carefully. To systemize all
the information for the diagnosis, prepare the interview sheet referring to the interview points.
• In some cases, multiple conditions that appear simultaneously may cause a DTC to be detected. J
Interview sheet sample

Interview sheet K
Registration Initial year
Customer number registration
MR/MS
name
Vehicle type VIN L
Storage date Engine Mileage km (Mile)
†The steering wheel position (center) is in the wrong position.
M
†Warning lamp turns on.
Symptom †Noise †Vibration
†Others N
( )
First occurrence †Recently †Others ( )
Frequency of occurrence †Always †Under a certain conditions of †Sometimes (time(s)/day) O
†Irrelevant

Climate con- Weather †Fine †Cloud †Rain †Snow †Others ( )

ditions
P
Temperature †Hot †Warm †Cool †Cold †Temperature [Approx. °C (°F)]
Relative humidity †High †Moderate †Low
†Urban area †Suburb area †High way
Road conditions
†Mountain road (uphill or down hill) †Rough road

Revision: May 2013 STC-19 2014 Pathfinder

 DIAGNOSIS AND REPAIR WORK FLOW
< BASIC INSPECTION >
Interview sheet
Registration Initial year
Customer number registration
MR/MS
name
Vehicle type VIN
Storage date Engine Mileage km (Mile)
†Irrelevant
†When engine starts †During idling
Operation conditions, etc. †During driving †During acceleration †At constant speed driving
†During deceleration †During cornering (right curve or left curve)
†During steering

Other conditions

Memo

Revision: May 2013 STC-20 2014 Pathfinder

 C1143 STEERING ANGLE SENSOR
< DTC/CIRCUIT DIAGNOSIS >
DTC/CIRCUIT DIAGNOSIS A
C1143 STEERING ANGLE SENSOR
DTC Logic INFOID:0000000009177138
B

DTC DETECTION LOGIC

C
DTC Display item Malfunction detected condition Possible cause
• Harness or connector
When a malfunction is detected in steering angle • Steering angle sensor
C1143 ST ANG SEN CIRCUIT D
sensor. • Power steering control mod-
ule

DTC CONFIRMATION PROCEDURE E

1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test. F

>> GO TO 2.
STC
2.DTC REPRODUCTION PROCEDURE
With CONSULT
1. Turn the ignition switch OFF to ON. H
2. Perform “EPS” self-diagnosis.
Is DTC “C1143” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-21, "Diagnosis Procedure". I
NO >> Inspection End.
Diagnosis Procedure INFOID:0000000009177139
J
1.CHECK STEERING ANGLE SENSOR CIRCUIT
Check steering angle sensor circuit. Refer to STC-21, "Diagnosis Procedure". K
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning component. L
2.CHECK TERMINALS AND HARNESS CONNECTORS
Check the power steering control module pin terminals for damage or loose connection with harness connec-
tor. M
Is the inspection result normal?
YES >> Power steering control module is malfunctioning. Replace power steering oil pump assembly.
Refer to ST-59, "Disassembly and Assembly". N
NO >> Repair or replace malfunctioning component.

Revision: May 2013 STC-21 2014 Pathfinder

 C1601 BATTERY POWER SUPPLY
< DTC/CIRCUIT DIAGNOSIS >
C1601 BATTERY POWER SUPPLY
DTC Logic INFOID:0000000009177140

DTC DETECTION LOGIC

DTC Display item Malfunction detected condition Possible cause

• Harness or connector
When a power supply voltage to the power steer- • Power steering control mod-
ing control module is maintained at 18.5 V or more ule
C1601 BATTERY VOLT
or at less than 8.5 V continuously for 0.5 seconds • Fuse
or more. • Battery power supply circuit
• Battery

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.
2.DTC REPRODUCTION PROCEDURE
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Perform “EPS” self-diagnosis.
Is DTC “C1601” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-22, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis Procedure INFOID:0000000009177141

Regarding Wiring Diagram information, refer to STC-14, "Wiring Diagram".

1.CHECK POWER STEERING CONTROL MODULE GROUND CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect power steering control module harness connector.
3. Check continuity between power steering control module harness connector terminal and ground.

Power steering control module

— Continuity
Connector Terminal
E63 2 Ground Yes
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair open circuit or short to ground or short to power in harness or connectors, and repair or
replace the malfunctioning component.
2.CHECK POWER STEERING CONTROL MODULE POWER SUPPLY CIRCUIT (1)
1. Check voltage between power steering control module harness connector terminals and ground.

Power steering control module Voltage

—
Connector Terminal (Approx.)

E63 1 Ground Battery voltage

Revision: May 2013 STC-22 2014 Pathfinder

 C1601 BATTERY POWER SUPPLY
< DTC/CIRCUIT DIAGNOSIS >
2. Turn ignition switch ON.
CAUTION: A
Never start the engine.
3. Check voltage between power steering control module harness connector terminals and ground.
B
Power steering control module Voltage
—
Connector Terminal (Approx.)

E63 1 Ground Battery voltage C

Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3. D

3.CHECK POWER STEERING CONTROL MODULE POWER SUPPLY CIRCUIT (2)

1. Turn ignition switch OFF. E
2. Check the 100A fusible link (#D).
3. Disconnect battery terminal with fusible link harness connector.
4. Check continuity between power steering control module harness connector terminal and battery terminal
F
with fusible link harness connector terminal.

Power steering control module Battery terminal with fusible link

Continuity STC
Connector Terminal Connector Terminal
E63 1 E7 3 Yes
5. Check continuity between power steering control module harness connector terminal and ground. H

Power steering control module

— Continuity I
Connector Terminal
E63 1 Ground No
Is the inspection result normal? J
YES >> Perform the trouble diagnosis for battery power supply circuit. Refer to PG-11, "Wiring Diagram -
BATTERY POWER SUPPLY -".
NO >> Repair or replace the malfunctioning component. K
4.CHECK POWER STEERING CONTROL MODULE POWER SUPPLY CIRCUIT (3)
1. Check voltage between power steering control module harness connector terminals and ground.
L

Power steering control module Voltage

—
Connector Terminal (Approx.)
M
E62 5 Ground 0V
2. Turn ignition switch ON.
CAUTION: N
Never start the engine.
3. Check voltage between power steering control module harness connector terminals and ground.
O
Power steering control module Voltage
—
Connector Terminal (Approx.)

E62 5 Ground Battery voltage P

Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.CHECK POWER STEERING CONTROL MODULE POWER SUPPLY CIRCUIT (4)
1. Turn ignition switch OFF.

Revision: May 2013 STC-23 2014 Pathfinder

 C1601 BATTERY POWER SUPPLY
< DTC/CIRCUIT DIAGNOSIS >
2. Check the 10A fuse No. 49 in the IPDM E/R.
3. Disconnect IPDM E/R harness connector E119.
4. Check continuity between power steering control module harness connector terminal and IPDM E/R har-
ness connector terminal.

Power steering control module IPDM E/R

Continuity
Connector Terminal Connector Terminal
E62 5 E119 35 Yes
5. Check continuity between power steering control module harness connector terminal and ground.

Power steering control module

— Continuity
Connector Terminal
E62 5 Ground No
Is the inspection result normal?
YES >> Perform the trouble diagnosis for ignition power supply circuit. Refer to PG-23, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace the malfunctioning component.
6.CHECK TERMINALS AND HARNESS CONNECTORS
Check the power steering control module pin terminals for damage or loose connection with harness connec-
tor.
Is the inspection result normal?
YES >> Power steering control module is malfunctioning. Replace steering oil pump assembly. Refer to
ST-52, "Removal and Installation".
NO >> Repair or replace the malfunctioning component.

Revision: May 2013 STC-24 2014 Pathfinder

 C1606 EPS MOTOR
< DTC/CIRCUIT DIAGNOSIS >
C1606 EPS MOTOR
A
DTC Logic INFOID:0000000009177142

DTC DETECTION LOGIC B

DTC Display item Malfunction detected condition Possible cause

• Harness or connector C
When the motor driver malfunction of power steer-
• Power steering control motor
C1606 EPS MOTOR ing control module or power steering control mod-
• Power steering control mod-
ule motor driver malfunction is detected.
ule
D
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING E
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.
F
>> GO TO 2.
2.DTC REPRODUCTION PROCEDURE
STC
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Perform “EPS” self-diagnosis.
H
Is DTC “C1606” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-25, "Diagnosis Procedure".
NO >> Inspection End.
I
Diagnosis Procedure INFOID:0000000009177143

1.PERFORM SELF-DIAGNOSIS J
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Erase self-diagnostic results for “EPS”. K
3. Turn the ignition switch OFF and wait for at least 10 seconds.
4. Perform self-diagnosis for “EPS”.
Is DTC “C1606” detected? L
YES >> Power steering motor is malfunctioning. Replace power steering oil pump assembly. Refer to ST-
52, "Removal and Installation".
NO >> Check pin terminal and connection of each harness connector for malfunctioning conditions.
M

Revision: May 2013 STC-25 2014 Pathfinder

 C1607, C1608 POWER STEERING CONTROL MODULE
< DTC/CIRCUIT DIAGNOSIS >
C1607, C1608 POWER STEERING CONTROL MODULE
DTC Logic INFOID:0000000009177144

DTC DETECTION LOGIC

DTC Display item Malfunction detected condition Possible cause

When the memory (EEPROM) system malfunction is
C1607 EEPROM
detected in power steering control module.
Power steering control module
When the internal malfunction is detected in power
C1608 CONTROL UNIT
steering control module.

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.
2.DTC REPRODUCTION PROCEDURE
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Perform “EPS” self-diagnosis.
Is DTC “C1607” or “C1608” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-26, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis Procedure INFOID:0000000009177145

1.PERFORM SELF-DIAGNOSIS
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Erase self-diagnostic results for “EPS”.
3. Turn the ignition switch OFF and wait for at least 10 seconds.
4. Perform self-diagnosis for “EPS”.
Is DTC “C1607” or “C1608” detected?
YES >> Power steering control module is malfunctioning. Replace power steering oil pump assembly.
Refer to ST-52, "Removal and Installation".
NO >> Check pin terminal and connection of each harness connector for malfunctioning conditions.

Revision: May 2013 STC-26 2014 Pathfinder

 C160A HEAT PROTECTION
< DTC/CIRCUIT DIAGNOSIS >
C160A HEAT PROTECTION
A
DTC Logic INFOID:0000000009177146

DTC DETECTION LOGIC B

DTC Display item Malfunction detected condition Possible cause

When the steering wheel is operated excessively C
and the interior temperature of the power steering
system reaches 118°C (244.4°F) or more. (Protec-
tion function)
The protection of the hydraulic D
NOTE:
C160A HEAT PROTECTION pump electric power steering sys-
Although the hydraulic pump electric power steering
tem
system warning lamp turns ON, this is not a system
malfunction. The state returns to normal after stop-
E
ping steering operation and waiting until the system
interior temperature drops to 90°C (194°F) or less.

DTC CONFIRMATION PROCEDURE F

1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test. STC

>> GO TO 2.
H
2.DTC REPRODUCTION PROCEDURE
With CONSULT
1. Turn the ignition switch OFF to ON. I
2. Perform “EPS” self-diagnosis.
Is DTC “C160A” detected?
YES >> Go to STC-18, "Work Flow". J
NO >> Inspection End.

Revision: May 2013 STC-27 2014 Pathfinder

 U1000 CAN COMM CIRCUIT
< DTC/CIRCUIT DIAGNOSIS >
U1000 CAN COMM CIRCUIT
Description INFOID:0000000009177147

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit communicate data but selectively reads required data only.
DTC Logic INFOID:0000000009177148

DTC DETECTION LOGIC

DTC Display item Malfunction detected condition Possible cause

Power steering control module is not transmitting/re-
U1000 CAN COMM CIRCUIT ceiving CAN communication signal for 2 seconds or CAN communication error
more.

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.
2.DTC REPRODUCTION PROCEDURE
With CONSULT
1. Turn the ignition switch OFF to ON.
2. Perform “EPS” self-diagnosis.
Is DTC “U1000” detected?
YES >> Go to STC-28, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis Procedure INFOID:0000000009177149

Proceed to LAN-20, "Trouble Diagnosis Flow Chart".

Revision: May 2013 STC-28 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP
< DTC/CIRCUIT DIAGNOSIS >
HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP
A
Component Function Check INFOID:0000000009177150

1.CHECK THE ILLUMINATION OF THE HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING B
LAMP
Check that the hydraulic pump electric power steering warning lamp turns ON when ignition switch turns ON.
Then, hydraulic pump electric power steering warning lamp turns OFF after the engine is started. C
Is the inspection result normal?
YES >> Inspection End.
NO >> Perform trouble diagnosis. Refer to STC-29, "Diagnosis Procedure". D

Diagnosis Procedure INFOID:0000000009177151

1.PERFORM SELF-DIAGNOSIS E

With CONSULT
1. Turn the ignition switch OFF to ON. F
2. Perform “EPS” self-diagnosis.
Is any DTC detected?
YES >> Check the DTC. Refer to STC-13, "DTC Index". STC
NO >> GO TO 2.
2.CHECK HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP SIGNAL
H
With CONSULT
1. Turn the ignition switch ON.
2. Select “WARNING LAMP” in “DATA MONITOR” of “EPS”.
3. Check that the item in “DATA MONITOR” is “On”. I
CAUTION:
Engine should not be running for step 3.
4. Start the engine. J
CAUTION:
Never drive the vehicle during the test.
5. Check that the item in “DATA MONITOR” is “Off”.
Is the inspection result normal? K
YES >> Perform the trouble diagnosis for combination meter power supply circuit. Refer to MWI-59,
"COMBINATION METER : Diagnosis Procedure".
NO >> GO TO 3. L
3.CHECK TERMINALS AND HARNESS CONNECTORS
Check the power steering control module pin terminals for damage or loose connection with harness connec- M
tor.
Is the inspection result normal?
YES >> Power steering control module is malfunctioning. Replace power steering oil pump assembly. N
Refer to ST-52, "Removal and Installation".
NO >> Repair or replace the malfunctioning component.
O

Revision: May 2013 STC-29 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP DOES
NOT TURN ON
< SYMPTOM DIAGNOSIS >
SYMPTOM DIAGNOSIS
HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP
DOES NOT TURN ON
Description INFOID:0000000009177152

The hydraulic pump electric power steering warning lamp does not illuminate when the ignition switch is
turned ON (lamp check).
Diagnosis Procedure INFOID:0000000009177153

1.CHECK THE HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP

Perform trouble diagnosis for the hydraulic pump electric power steering warning lamp system. Refer to STC-
29, "Diagnosis Procedure".
Is the inspection result normal?
YES >> Check that the pin terminals and the connection of each connector are normal.
NO >> Repair or replace the malfunctioning components.

Revision: May 2013 STC-30 2014 Pathfinder

 HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP DOES
NOT TURN OFF
< SYMPTOM DIAGNOSIS >
HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP
A
DOES NOT TURN OFF
Description INFOID:0000000009177154
B
Hydraulic pump electric power steering warning lamp does not turn OFF several seconds after engine started
Diagnosis Procedure INFOID:0000000009177155
C
1.PERFORM SELF-DIAGNOSIS
With CONSULT D
Perform “EPS” self-diagnosis.
Is any DTC detected?
YES >> Check the DTC. Refer to STC-13, "DTC Index". E
NO >> GO TO 2.
2.CHECK HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING LAMP
Perform the trouble diagnosis of hydraulic pump electric power steering warning lamp. Refer to STC-29, F
"Diagnosis Procedure".
Is the inspection result normal?
STC
YES >> GO TO 3.
NO >> Repair or replace the malfunctioning components.
3.POWER STEERING CONTROL MODULE POWER SUPPLY AND GROUND CIRCUIT H
Perform the trouble diagnosis of power steering control module power supply and ground. Refer to STC-22,
"Diagnosis Procedure".
Is the inspection result normal? I
YES >> Check that the pin terminals and the connection of each connector are normal.
NO >> Repair or replace the malfunctioning components.
J

Revision: May 2013 STC-31 2014 Pathfinder

 STEERING WHEEL TURNING FORCE IS HEAVY OR LIGHT
< SYMPTOM DIAGNOSIS >
STEERING WHEEL TURNING FORCE IS HEAVY OR LIGHT
Diagnosis Procedure INFOID:0000000009177156

1.PERFORM SELF-DIAGNOSIS
With CONSULT
Perform “EPS” self-diagnosis.
Is a malfunctioning system displayed?
YES >> Check malfunctioning system. Refer to STC-13, "DTC Index".
NO >> GO TO 2.
2.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (1)
With CONSULT
1. Start the engine.
CAUTION:
Never drive the vehicle.
2. Turn the steering wheel until it stops.
3. Select “MTR ASSIST” in “DATA MONITOR” of “EPS”.
Is the display value “100%”?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (2)
With CONSULT
1. Select “C/U TEMP” and “C/U TEMP A” in “DATA MONITOR” of “EPS”.
2. Stop the system until the DATA MONITOR display value drops to “90°C (194°F)” or less.
3. Check whether symptom continues.
Did symptom continue?
YES >> GO TO 4.
NO >> This occurs because the protection function lowers the assist force. It is not a system malfunction.
Inspection End.
4.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (3)
With CONSULT
1. Turn the steering wheel to the straight-ahead position. (There is no steering force)
2. Select “BATTERY VOLT” in “DATA MONITOR” of “EPS”.
Is the display value “10.5 V” or more?
YES >> GO TO 5.
NO >> Check the battery power system. Refer to STC-22, "Diagnosis Procedure".
5.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (4)
With CONSULT
Select “ESTM VHCL SPD” in “DATA MONITOR” of “EPS”.

Monitor item Test condition Display value

When stopped 0.00 km/h or mph

ESTM VHCL SPD Approximately equal to the in-

While driving dication on speedometer*
(Inside of ±10%)
*: This may not agree with the speedometer indication immediately after the ignition switch is turned ON. This
is not a malfunction.
Is the check result normal?
YES >> GO TO 6.
NO >> Check the combination meter, ABS actuator and electric unit (control unit). Refer to MWI-19,
"CONSULT Function (METER/M&A)" and STC-10, "CONSULT Function".

Revision: May 2013 STC-32 2014 Pathfinder

 STEERING WHEEL TURNING FORCE IS HEAVY OR LIGHT
< SYMPTOM DIAGNOSIS >
6.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (5) A
With CONSULT
Select “STR ANG SPD” in “DATA MONITOR” of “EPS”.
B
Monitor item Test condition Display value
The steering wheel is not
Approx. 0.0 deg/s
steered. C
STR ANG SPD
Displays steering angle speed
The steering wheel is steered.
(deg/s)
Is the check result normal? D
YES >> GO TO 7.
NO >> Check the steering angle sensor. Refer to STC-21, "Diagnosis Procedure".
7.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (6) E

With CONSULT
Select “ENGINE STATUS” in “DATA MONITOR” of “EPS”.
F
Is the display value “RUN”?
YES >> GO TO 8.
NO >> Check the ECM. Refer to EC-61, "CONSULT Function". STC
8.CHECK THE STEERING FORCE
Check the steering force. Refer to STC-34, "Diagnosis Procedure".
H
Is the check result normal?
YES >> Inspection End.
NO >> It is possible that there is a mechanical malfunction. Check the steering system.
I

Revision: May 2013 STC-33 2014 Pathfinder

 UNBALANCE STEERING WHEEL TURNING FORCE AND RETURN BETWEEN
RIGHT AND LEFT
< SYMPTOM DIAGNOSIS >
UNBALANCE STEERING WHEEL TURNING FORCE AND RETURN BE-
TWEEN RIGHT AND LEFT
Diagnosis Procedure INFOID:0000000009177157

1.CHECK THE ILLUMINATION OF THE HYDRAULIC PUMP ELECTRIC POWER STEERING WARNING
LAMP
Check the hydraulic pump electric power steering warning lamp while engine is running.
Does the hydraulic pump electric power steering warning lamp turn OFF?
YES >> GO TO 2.
NO >> Refer to STC-31, "Diagnosis Procedure".
2.CHECK WHEEL ALIGNMENT
Check the wheel alignment. Refer to FSU-19, "Wheel Alignment".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Adjustment of wheel alignment. Refer to FSU-19, "Wheel Alignment".
3.CHECK STEERING WHEEL TURNING FORCE
Check the steering wheel turning force. Refer to STC-35, "Diagnosis Procedure".
Is the inspection result normal?
YES >> Inspection End.
NO >> Check the steering wheel turning force for mechanical malfunction. Refer to STC-32, "Diagnosis
Procedure".

Revision: May 2013 STC-34 2014 Pathfinder

 UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION)
< SYMPTOM DIAGNOSIS >
UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIA-
A
TION)
Diagnosis Procedure INFOID:0000000009177158
B
1.PERFORM SELF-DIAGNOSIS
With CONSULT C
Perform “EPS” self-diagnosis.
Is a malfunctioning system displayed?
YES >> Check malfunctioning system. Refer to STC-13, "DTC Index". D
NO >> GO TO 2.
2.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (1)
With CONSULT E
1. Start the engine.
CAUTION:
Never drive the vehicle. F
2. Turn the steering wheel until it stops.
3. Select “MTR ASSIST” in “DATA MONITOR” of “EPS”.
Is the display value “100%”? STC
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (2) H
With CONSULT
1. Select “C/U TEMP” and “C/U TEMP A” in “DATA MONITOR” of “EPS”.
2. Stop the system until the DATA MONITOR display value drops to “90°C (194°F)” or less. I
3. Check whether symptom continues.
Did symptom continue?
YES >> GO TO 4. J
NO >> This occurs because the protection function lowers the assist force. It is not a system malfunction.
Inspection End.
4.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (3) K

With CONSULT
1. Turn the steering wheel to the straight-ahead position. (There is no steering force.) L
2. Select “BATTERY VOLT” in “DATA MONITOR” of “EPS”.
Is the display value “10.5 V” or more?
YES >> GO TO 5. M
NO >> Check the battery power system. Refer to STC-22, "Diagnosis Procedure".
5.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (4)
With CONSULT N
Select in “ESTM VHCL SPD” in “DATA MONITOR” of “EPS”.

Monitor item Test condition Display value O

When stopped 0.00 km/h or mph

ESTM VHCL SPD Approximately equal to the in-

P
While driving dication on speedometer*
(Inside of ±10%)
*: This may not agree with the speedometer indication immediately after the ignition switch is turned ON. This
is not a malfunction.
Is the check result normal?
YES >> GO TO 6.

Revision: May 2013 STC-35 2014 Pathfinder

 UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION)
< SYMPTOM DIAGNOSIS >
NO >> Check the combination meter, ABS actuator and electric unit (control unit). Refer to MWI-19,
"CONSULT Function (METER/M&A)" and STC-10, "CONSULT Function".
6.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (5)
With CONSULT
Select “STR ANG SPD” in “DATA MONITOR” of “EPS”.

Monitor item Test condition Display value

The steering wheel is not turn-
Approx. 0.0 deg/s
ing.
STR ANG SPD
The steering wheel is being Displays steering angle speed
turned. (deg/s)
Is the check result normal?
YES >> GO TO 7.
NO >> Check the steering angle sensor. Refer to STC-21, "Diagnosis Procedure".
7.CHECK THE POWER STEERING CONTROL MODULE SIGNAL (6)
With CONSULT
Select “ENGINE STATUS” in “DATA MONITOR” of “EPS”.
Is the display value “RUN”?
YES >> GO TO 8.
NO >> Check the ECM. Refer to EC-61, "CONSULT Function".
8.CHECK STEERING COLUMN AND STEERING GEAR
Check the steering column assembly and steering gear assembly.
• Steering column assembly. Refer to ST-60, "Steering Column".
• Steering gear assembly. Refer to ST-61, "Power Steering Gear".
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair or replace malfunctioning component.
9.CHECK STEERING WHEEL TURNING FORCE
Check the steering wheel turning force. Refer to STC-32, "Diagnosis Procedure".
Is the inspection result normal?
YES >> Inspection End.
NO >> Check the steering wheel turning force for mechanical malfunction. Refer to STC-32, "Diagnosis
Procedure".

Revision: May 2013 STC-36 2014 Pathfinder

 POWER STEERING CONTROL MODULE
< REMOVAL AND INSTALLATION >
REMOVAL AND INSTALLATION A
POWER STEERING CONTROL MODULE
Removal and Installation INFOID:0000000009177159
B
CAUTION:
Disconnect battery negative cable before removing the power steering pump assembly.
The power steering control module is an integral part of the power steering pump assembly. If replacement of C
the power steering control module is necessary, replace the complete power steering pump assembly. Refer
to ST-52, "Removal and Installation".
D

STC

Revision: May 2013 STC-37 2014 Pathfinder