2011 INFINITI QX56 power steering

SRC-6
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006219946
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.
ServiceINFOID:0000000006219947
 Never use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
 Before servicing the SRS, turn ignition switch OF F, disconnect battery negative terminal and wait 3 minutes
or more.
For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-
tensioner to deploy. Therefore, never work on any SR S connectors or wires until at least 3 minutes have
passed.
 Diagnosis sensor unit must always be installed with their arrow marks “ ⇐” pointing towards the front of the
vehicle for proper operation. Also chec k diagnosis sensor unit for cracks, deformities or rust before installa-
tion and replace as required.
 The spiral cable must be aligned with the neutral position since its rotations are limited. Never turn steering
wheel and column after removal of steering gear.
 Handle air bag module carefully. Always place driver and front passenger air bag modules with the pad side facing upward and seat mounted front side air bag module standing with the stud bolt side facing down.
 Conduct self-diagnosis to check entire SRS for proper function after replacing any components.
 After air bag inflates, the front instrument panel assembly should be replaced if damaged.
 Always replace instrument panel pad following front passenger air bag deployment.
 Never solder the harness when making repairs. Check that harness is not pinched and that there is no con-
tact with other components.
 Never allow harness to come in contact with oil, grease, waste oil, or water.
 Never insert foreign materials, such as a screwdriver , into the harness connector. (This is to prevent acci-
dental activation caused by static electricity.)
 Always use CONSULT-III or SRS air bag warning lamp to perform the circuit diagnosis. (Never use an elec- tric tester such as a circuit tester.)
 Never enter in the deployment area of the pop-up roll bar. Never put an object in the deployment area of the
pop-up roll bar. (This is to prevent injury in case of an unintentional deployment.)
Revision: 2010 May2011 QX56

COMPONENT PARTSSRC-9
< SYSTEM DESCRIPTION >
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Component DescriptionINFOID:0000000006219949
13. Occupant detection system control unit 14. Occupant detection system seat
sensor 15. Crash zone sensor
16. Combination switch (spiral cable)
A. Behind center pillar lower garnish B. View with seatback pad removed C. View with laggage side finisher lower removed
D. View with headlining assembly re- moved E. View with headlining assembly re-
moved F. View with center console assembly
removed
G. Backside of passenger seat cushion frame H. View with bumper fascia assembly
removed I. View with steering wheel removed
Component Function
Air bag diagnosis sensor unit  Detects a collision and supplies power supply for deployment to air bag module and
pre-tensioner seat belt.
 It contains the “G” sensors for both frontal and side collisions and spare battery function in case of main battery damage in collision.
Combination meter (air bag warning lamp) Indicates air bag malfunctioning and deployment by blinking and illuminating air bag
warning lamp.
Combination switch (spiral cable) Supplies power supply to driver air bag module on steering wheel.
Crash zone sensor  Transmits signal to air bag diagnosis sensor unit when a frontal collision occurs.
 Crash zone sensor is a G sensor that outputs voltage signal during deceleration at
the time of a vehicle frontal collision that is more than the specified limit is detected.
Curtain air bag module (front/rear)  Deploys according to collision judgment of G sensor, and safing sensor.
 Receives collision signal from air bag diagnosis sensor unit, ignites, and burns ig-
nition material by electric ignition system, when side collision exceeds setting limit
of the vehicle. Gas is generated by chemical reaction of ignition material, passes
filter, and deploys air bag.
 Air bag module mainly consists of air bag and inflator that deploys air bag.
Driver air bag module  Receives signal from air bag diagnosis sensor unit and deploys air bag.
 In case of frontal collision where acceleration is more than the specified level, the
ignition materials are ignited by electric ignition system. The system burns the gas
generating materials resulting in a chemical reaction. This generates hot gases that
flow into the air bag through a filter and expand the bag.
Occupant detection system control unit Detects front passenger seat occupant.
Passenger air bag module  Receives signal from air bag diagnosis sensor unit and deploys air bag.
 In case of frontal collision where acceleration is more than the specified level, the
ignition materials are ignited by electric ignition system. The system burns the gas
generating materials resulting in a chemical reaction. This generates hot gases that
flow into the air bag through a filter and expand the bag.
Passenger air bag OFF indicator Indicates whether or not passenger air bag is in the activation mode based on the
judgement of occupant classification system.
Satellite sensor (front/rear)  Transmits signal to air bag diagnosis sensor unit when a side collision occurs.
 When air bag diagnosis sensor unit defines both signal voltage of the “G” sensor,
and the safing algorithm to be that of collision which is more than the specified lev-
el, the driving circuit switches on and feeds the electric ignitor of both the side air
bag and curtain air bag and seat belt pre-tensioner.
Seat belt buckle switch LH/RH Controls deployment timing depending on the seat belt condition that is fastened or
unfastened.
Seat belt pre-tensioner LH/RH  Receives signal from air bag diagnosis sensor unit and deploys seat belt pre-ten-
sioner.
 In the case of a frontal collision or side collision or roll over that exceeds specified impact level, the air bag diagnosis sensor unit detects the deceleration caused by
collision. It restrains the passenger with seat belt easing the stress on passengers
chest with load limiter.
Revision: 2010 May2011 QX56

ST-1
STEERING
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CONTENTS
STEERING SYSTEM
PRECAUTION ................ ...............................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
3
Service Notice or Precautions for Steering System
......
4
PREPARATION ............................................5
PREPARATION .............................................. .....5
Special Service Tools .......................................... ......5
Commercial Service Tools ........................................6
SYSTEM DESCRIPTION ..............................7
COMPONENT PARTS ................................... .....7
Component Parts Location (Heated Steering
Wheel) ................................................................. ......
7
Component Description (Heated Steering Wheel) ......7
Heated Steering Wheel .............................................7
Heated Steering Wheel Switch .................................8
Heated Steering Wheel Relay ...................................8
SYSTEM ..............................................................9
System Description (Heated Steering Wheel) ..... ......9
WIRING DIAGRAM ......................................10
HEATED STEERING WHEEL ........................ ....10
Wiring Diagram ................................................... ....10
BASIC INSPECTION ...................................13
DIAGNOSIS AND REPAIR WORK FLOW .... ....13
WorkFlow (Heated Steering Wheel) .................... ....13
STEERING WHEEL ............................................14
Inspection ............................................................ ....14
DTC/CIRCUIT DIAGNOSIS .........................16
HEATED STEERING WHEEL SYSTEM ...........16
Component Function Check ................................ ....16
Diagnosis Procedure ...............................................16
Component Inspection (Heated Steering Wheel) ....18
Component Inspection (Heated Steering Wheel
Relay) ......................................................................
19
HEATED STEERING WHEEL SWITCH INDI-
CATOR LAMP ...................................................
20
Component Function Check ....................................20
Diagnosis Procedure ...............................................20
Component Inspection (Heated Steering Wheel
Relay) ......................................................................
22
SYMPTOM DIAGNOSIS ..............................23
HEATED STEERING WHEEL SYSTEM DOES
NOT ACTIVATE ................................................
23
Description ........................................................... ....23
Diagnosis Procedure ...............................................23
HEATED STEERING WHEEL SWITCH INDI-
CATOR LAMP DOES NOT TURN ON ..............
26
Description ...............................................................26
Diagnosis Procedure ...............................................26
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ...........................
29
NVH Troubleshooting Chart ....................................29
PERIODIC MAINTENANCE ........................30
POWER STEERING FLUID ..............................30
Inspection ............................................................ ....30
STEERING WHEEL ..........................................32
Inspection ................................................................32
REMOVAL AND INSTALLATION ...............33
Revision: 2010 May2011 QX56

ST-2
STEERING WHEEL ...........................................33
Exploded View ..................................................... ...33
Removal and Installation ........................................33
STEERING COLUMN ........................................34
Exploded View ..................................................... ...34
Removal and Installation ........................................34
Inspection ...............................................................35
STEERING SHAFT ............................................37
Exploded View ..................................................... ...37
Removal and Installation ........................................37
Inspection ...............................................................39
STEERING GEAR AND LINKAGE ....................41
Exploded View ..................................................... ...41
Removal and Installation ........................................42
Disassembly and Assembly ....................................43
Inspection ...............................................................46
POWER STEERING OIL PUMP ........................48
Exploded View ..................................................... ...48
Removal and Installation ........................................49
Disassembly and Assembly ....................................50
Inspection ...............................................................52
HYDRAULIC LINE .......................................... ...54
Exploded View ..................................................... ...54
HEATED STEERING WHEEL SWITCH ............56
Exploded View ..................................................... ...56
Removal and Installation .........................................56
SERVICE DATA AND SPECIFICATIONS
(SDS) .......... ................................................
57
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ...
57
General Specifications ......................................... ...57
Steering Wheel Axial End Play and Play ................57
Steering Wheel Turning Force ................................57
Steering Angle ........................................................57
Steering Column Length .........................................57
Steering Column Mounting Dimensions ..................57
Steering Column Operating Range .........................57
Steering Shaft Sliding Range ..................................58
Rack Sliding Force ..................................................58
Rack Stroke ............................................................58
Socket Swing Force and Rotating Torque ..............58
Socket Axial End Play .............................................58
Inner Socket Length ................................................58
Relief Oil Pressure ..................................................58
Revision: 2010 May2011 QX56

PRECAUTIONSST-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006272045
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 whether 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 inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent 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 minutes before performing any service.
Precaution Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006272046
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both 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 batte ry 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 wil l 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

ST-6
< PREPARATION >
PREPARATION
Commercial Service Tools
INFOID:0000000006225575
Tool name Description
Power tool Loosening bolts and nuts
Ball joint remover Remove steering outer socket
Drift
a: 35 mm (1.38 in) dia.
b: 21 mm (0.83 in) dia. Installing oil pump oil seal
PBIC0190E
S-NT146
S-NT474
Revision: 2010 May2011 QX56

ST-8
< SYSTEM DESCRIPTION >
COMPONENT PARTS
Furthermore, the heated steering wheel incorporates a heating element and a thermostat to control heated
steering wheel temperatures.
 Heating element: Heat is generated by the passage of an electric current.
 Thermostat: ON/OFF operation of power supply at a certain temperature.
Heated Steering Wheel SwitchINFOID:0000000006225579
 Controls the heated steering wheel relay and operates the heated steering wheel system.
The heated steering wheel switch incorporates a ti mer and turns OFF the heated steering wheel relay when
operating time reaches a certain time.
- Timer: ON/OFF operation of the heated st eering wheel relay at a certain time.
 Turns the indicator lamp ON when the system is activated.
Heated Steering Wheel RelayINFOID:0000000006225580
Operates the heated steering system with the control signal from the heated steering wheel switch.
Revision: 2010 May2011 QX56

ST-14
< BASIC INSPECTION >
STEERING WHEEL
STEERING WHEEL
InspectionINFOID:0000000006225584
NEUTRAL POSITION STEERING WHEEL
1. Check that steering gear assembly, steering column assembly and steering wheel are installed in the cor-
rect position.
2. Perform neutral position inspection after wheel alignment. Refer to FSU-7, "
Inspection".
3. Set vehicle to the straight-ahead position and c onfirm steering wheel is in the neutral position.
4. Loosen outer socket lock nut and turn inner socket to left and right equally to make fine adjustments if steering wheel is not in the neutral position.
STEERING WHEEL TURNING FORCE
1. Park vehicle on a level and dry surface, set parking brake.
2. Tires need to be inflated the specified pressure. Refer to WT-69, "
Tire Air Pressure".
3. Start the engine.
4. Bring power steering fluid up to adequate operating temperature.
5. Check steering wheel turning force when steering wheel has been turned 540 ° from neutral position.
NOTE:
Multiply the distance (L) from the hook of spring balance to the
center of steering wheel by the measurement value with a spring
balance.
6. If steering wheel turning force is out of the specification, check
rack sliding force and relief hydraulic pressure of oil pump.
Regarding relief hydraulic pressure of oil pump, refer to ST-52, "
Inspection".
RACK SLIDING FORCE
1. Disconnect lower joint and steering knuckle from steering gear assembly. Refer to ST-41, "Exploded
View".
2. Start and run engine at idle to make sure steer ing fluid has reached normal operating temperature.
3. While pulling outer socket slowly in ±11.5 mm ( ±0.453 in) range
from neutral position, make sure rack sliding force is within
specification.
4. If rack sliding force is not within specification, overhaul steering gear assembly.
FRONT WHEEL TURNING ANGLE
1. Check front wheel turning angle after toe-in inspection. Refer to FSU-7, "Inspection".
Fluid temperature : 50 – 80
°C (122 – 176 °F)
Steering wheel turning
force : Refer to
ST-57, "
Steering
Wheel Turning Force".
JSGIA0027ZZ
Fluid temperature : 50 – 80 °C (122 – 176 °F)
Rack sliding force : Refer to ST-58, "
Rack
Sliding Force".
SST090B
Revision: 2010 May2011 QX56