2011 INFINITI QX56 BATTERY

POWER STEERING OIL PUMPST-49
< REMOVAL AND INSTALLATION >
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Removal and InstallationINFOID:0000000006225612
REMOVAL
1. Drain power steering fluid from reservoir tank. CAUTION:
 Never reuse drained power steering fluid.
 Always use the specified fluid. Refer to MA-10, "
Fluids and Lubricants".
2. Remove the reservoir tank. Refer to CO-13, "
Removal and Installation".
3. Remove the battery and battery tray from vehicle. Refer to PG-164, "
Removal and Installation".
4. Loosen drive belt. Refer to EM-20, "
Removal and Installation".
5. Remove drive belt from oil pump pulley.
6. Remove copper washers and eye bolt (drain fluid from their pipings).
7. Remove suction hose (drain fluid from their pipings).
8. Remove oil pump mounting bolts, and then remove oil pump.
INSTALLATION
1. Pulley 2. Snap ring 3. Drive shaft assembly
4. Oil seal 5. Body assembly 6. Suction pipe
7. O-ring 8. Side plate 9. Vane
10. Rotor 11. Cam ring 12. Cartridge
13. Dowel pin 14. Gasket 15. Rear cover
16. Flow control valve spring 17. Flow control valve 18. Connector bolt
19. Bracket
: Replace the parts as a set.
A. Oil seal lip
: Apply power steering fluid.: Apply multi-purpose grease.
Refer to GI-4, "
Components" for symbols not described on the above.
JPGIA0032GB
Revision: 2010 May2011 QX56

STC-1
STEERING
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SECTION STC
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CONTENTS
STEERING CONTROL SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
2
SYSTEM DESCRIPTION ..............................4
COMPONENT PARTS ................................... .....4
Component Parts Location .................................. ......4
Component Description .............................................4
Power Steering Control Unit ......................................4
Power Steering Solenoid Valve .................................4
SYSTEM ..............................................................5
EPS SYSTEM ........................................ ......................5
EPS SYSTEM : System De scription .........................5
EPS SYSTEM : Fail-Safe ..........................................6
ECU DIAGNOSIS INFO RMATION ...............8
POWER STEERING CONTROL UNIT ........... .....8
Reference Value ................................................. ......8
Fail-Safe ....................................................................9
WIRING DIAGRAM ......................................10
ELECTRONICALLY CONTROLLED POWER
STEERING SYSTEM ...................................... ....
10
Wiring Diagram ................................................... ....10
BASIC INSPECTION ...................................13
DIAGNOSIS AND REPAIR WORK FLOW .......13
Work Flow ............................................................ ....13
DTC/CIRCUIT DIAGNOSIS .........................14
POWER SUPPLY AND GROUND CIRCUIT ....14
Diagnosis Procedure ........................................... ....14
POWER STEERING SOLENOID VALVE .........16
Component Function Check ....................................16
Diagnosis Procedure ...............................................16
Component Inspection .............................................17
ENGINE SPEED SIGNAL CIRCUIT ..................18
Diagnosis Procedure ........................................... ....18
VEHICLE SPEED SIGNAL CIRCUIT ................20
Diagnosis Procedure ...............................................20
SYMPTOM DIAGNOSIS ..............................22
UNBALANCE STEERING WHEEL TURNING
FORCE (TORQUE VARIATION) .......................
22
Description ........................................................... ....22
Diagnosis Procedure ...............................................22
REMOVAL AND INSTALLATION ...............23
POWER STEERING CONTROL UNIT ..............23
Removal and Installation ..................................... ....23
Revision: 2010 May2011 QX56

STC-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006303358
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition 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
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006303360
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the bat tery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

PRECAUTIONSSTC-3
< PRECAUTION >
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5. When the repair work is completed, re-connect both battery cables. With the brake pedal released, turn
the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering
wheel will lock when the push-button ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of a ll control units using CONSULT-III.
Revision: 2010 May2011 QX56

STC-8
< ECU DIAGNOSIS INFORMATION >
POWER STEERING CONTROL UNIT
ECU DIAGNOSIS INFORMATION
POWER STEERING CONTROL UNIT
Reference Value INFOID:0000000006256121
TERMINAL LAYOUT
PHYSICAL VALUES
JSGIA0023ZZ
Te r m i n a l N o .(Wire color) Description
Condition Value (Approx.)
+ - Signal name Input/
Output
1
(R) GroundPower steering
solenoid
valve control voltage OutputVehicle speed: 0 km/h (0 MPH)
(Engine is running)
4.4 – 6.6 V
Vehicle speed: 100 km/h (62 MPH) 2.4 – 3.6 V
3
(GR) GroundIgnition switch power
supply InputIgnition switch: ON Battery voltage
Ignition switch: OFF 0 V
5
(L) Ground
Power steering
solenoid
valve ground —Always 0 V
6
(B) Ground Ground — Always 0 V
8
(SB) Ground Vehicle speed signal Input Vehicle speed: 40 km/h (25 MPH)
CAUTION:
Check air pressure of tire under
standard condition.NOTE:
The maximum voltage varies de-
pending on the specification
(destination unit).
JSNIA0015GB
Revision: 2010 May2011 QX56

STC-14
< DTC/CIRCUIT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
DTC/CIRCUIT DIAGNOSIS
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006256125
1.CHECK POWER SUPPLY (1)
1. Turn the ignition switch OFF.
2. Disconnect power steering control unit harness connector.
3. Check the voltage between power steering control unit harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start the engine.
5. Check the voltage between power steering control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK POWER SUPPLY (2)
1. Turn the ignition switch OFF.
2. Check 10A fuse (#3).
3. Disconnect fuse block (J/B) harness connector.
4. Check the continuity between power steering cont rol unit harness connector and fuse block (J/B) harness
connector.
5. Check the continuity between power st eering control unit harness connector and ground.
Is the inspection result normal?
YES >> Perform trouble diagnosis for ignition power supply circuit. Refer to PG-89, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn the ignition switch OFF.
2. Check the continuity between power st eering control unit harness connector and ground.
Power steering control unit
—Voltage
Connector Terminal
M108 3 Ground 0 V
Power steering control unit — Voltage
Connector Terminal
M108 3 Ground Battery voltage
Power steering control unit Fuse block (J/B) Continuity
Connector Terminal Connector Terminal
M108 3 M1 2A Existed
Power steering control unit —Continuity
Connector Terminal
M108 3 Ground Not existed
Revision: 2010 May2011 QX56

POWER STEERING SOLENOID VALVESTC-17
< DTC/CIRCUIT DIAGNOSIS >
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4.CHECK TERMINALS AND HARNESS CONNECTORS
 Check the power steering control unit pin terminal s for damage or loose connection with harness connector.
 Check the power steering solenoid valve pin termi nals for damage or loose connection with harness connec-
tor.
Is the inspection result normal?
YES >> Replace power steering control unit. Refer to STC-23, "Removal and Installation".
NO >> Repair or replace error-detected parts.
Component Inspection INFOID:0000000006256128
1.CHECK POWER STEERING SOLENOID VALVE
1. Turn the ignition switch OFF.
2. Disconnect power steering solenoid valve harness connector.
3. Check resistance between power steering solenoid valve connector terminals.
4. Check power steering solenoid valve by listening for its operation sound while applying battery voltage to
power steering solenoid valve connector terminals 1 (positive) and 2 (negative).
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace gear-sub assembly. Refer to ST-43, "
Disassembly and Assembly".
Power steering solenoid valve
Resistance (Approx.)
Te r m i n a l
1 2 4 – 6 Ω
Revision: 2010 May2011 QX56

STR-1
ENGINE
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SECTION STR
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CONTENTS
STARTING SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
2
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tools .......................................... ......4
Commercial Service Tools ........................................4
SYSTEM DESCRIPTION ..............................5
COMPONENT PARTS ................................... .....5
Component Parts Location .................................. ......5
Component Description ............................................5
SYSTEM ..............................................................6
System Diagram .................................................. ......6
System Description ...................................................6
WIRING DIAGRAM .......................................7
STARTING SYSTEM ...................................... .....7
Wiring Diagram ................................................... ......7
BASIC INSPECTION ...................................11
DIAGNOSIS AND REPAIR WORKFLOW ........11
Work Flow ............................................................ ....11
DTC/CIRCUIT DIAGNOSIS .........................14
B TERMINAL CIRCUIT .....................................14
Diagnosis Procedure ........................................... ....14
S CONNECTOR CIRCUIT .................................15
Diagnosis Procedure ...............................................15
SYMPTOM DIAGNOSIS ..............................16
STARTING SYSTEM .........................................16
Symptom Table ................................................... ....16
REMOVAL AND INSTALLATION ...............17
STARTER MOTOR ...........................................17
Exploded View ..................................................... ....17
Removal and Installation .........................................18
Inspection ................................................................18
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .............................................
20
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
20
Starter Motor .......................................................
Revision: 2010 May2011 QX56