2011 INFINITI QX56 Wiring

ST-22
< DTC/CIRCUIT DIAGNOSIS >
HEATED STEERING WHEEL SWITCH INDICATOR LAMP
7.DETECT MALFUNCTIONING ITEM
Check the following.
 Ignition switch
 Harness for short or open between ignition switch and fuse block (J/B). Refer to PG-11, "
Wiring Diagram -
BATTERY POWER SUPPLY -".
 10A fuse [No.3, located in the fuse block (J/B)]. Refer to PG-143, "
Fuse, Connector and Terminal Arrange-
ment".
 Fuse block (J/B)
Is the inspection result normal?
YES >> Replace heated steering wheel switch. Refer to ST-56, "Removal and Installation".
NO >> Repair or replace damaged parts.
Component Inspection (H eated Steering Wheel Relay)INFOID:0000000006225591
1.CHECK HEATED STEERING WHEEL RELAY CONTINUITY
Check continuity between heated steering wheel relay terminals.
CAUTION:
Connect the fuse between the termi nals when applying the voltage.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace heated steering wheel relay. Refer to ST-7, "
Component Parts Location (Heated Steering
Wheel)".
Heated steering wheel relay
Condition Continuity
Terminal
3 − 5 Apply 12 V direct current be-
tween terminals 1 and 2.
Existed
Other conditions. Not existed
Revision: 2010 May2011 QX56

ST-24
< SYMPTOM DIAGNOSIS >
HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
5. Check continuity between heated steering wheel relay harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK HEATED STEERING WHEEL RELAY
Check heated steering wheel relay. Refer to ST-19, "
Component Inspection (Heated Steering Wheel Relay)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace heated steering wheel relay. Refer to ST-7, "
Component Parts Location (Heated Steering
Wheel)".
6.DETECT MALFUNCTIONING ITEM
Check the following.
Battery
 Harness for short or open between bat tery and IPDM E/R. Refer to PG-11, "
Wiring Diagram - BATTERY
POWER SUPPLY -".
 10A fuse (No.76, located in the IPDM E/R). Refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
 IPDM E/R
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.CHECK GROUND CIRCUIT
Check continuity between heated steering wheel switch harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace damaged parts.
8.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
SWITCH
1. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
2. Check continuity between heated steering w heel relay harness connector terminal and ground.
Heated steering wheel relay Heated steering wheel
Continuity
Connector Terminal Connector Terminal
E90 5 M303 1 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 5 Not existed
Heated steering wheel switch GroundContinuity
Connector Terminal
M52 6 Existed
Heated steering wheel relay Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
E90 2 M52 2 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 2 Not existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
ST-25
< SYMPTOM DIAGNOSIS >
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Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair or replace damaged parts.
9.CHECK HARNESS BETWEEN FUSE BLOCK (J/B) AND HEATED STEERING WHEEL SWITCH
1. Check continuity between fuse block (J/B) connec tor terminal and heated steering wheel switch harness
connector terminal.
2. Check continuity between fuse block (J/B) harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Repair or replace damaged parts.
10.DETECT MALFUNCTIONING ITEM
Check the following.
 Ignition switch
 Harness for short or open between ignition s witch and fuse block (J/B). Refer to PG-11, "
Wiring Diagram -
BATTERY POWER SUPPLY -".
 10A fuse [No.3, located in the fuse block (J/B)]. Refer to PG-143, "
Fuse, Connector and Terminal Arrange-
ment".
 Fuse block (J/B)
Is the inspection result normal?
YES >> Replace heated steering wheel switch. Refer to ST-56, "Removal and Installation".
NO >> Repair or replace damaged parts.
Fuse block (J/B) Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
M1 2A M52 1 Existed
Fuse block (J/B) GroundContinuity
Connector Terminal
M1 2A Not existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SWITCH INDICATOR LAMP DOES NOT TURN ON
ST-27
< SYMPTOM DIAGNOSIS >
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Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK HEATED STEERING WHEEL RELAY
Check heated steering wheel relay. Refer to ST-22, "
Component Inspection (Heated Steering Wheel Relay)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace heated steering wheel relay. Refer to ST-7, "
Component Parts Location (Heated Steering
Wheel)".
5.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
SWITCH
1. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
2. Check continuity between heated steering w heel relay harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
6.CHECK HARNESS BETWEEN FUSE BLOCK (J/B) AND HEATED STEERING WHEEL SWITCH
1. Check continuity between fuse block (J/B) connec tor terminal and heated steering wheel switch harness
connector terminal.
2. Check continuity between fuse block (J/B) harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.DETECT MALFUNCTIONING ITEM
Check the following.
 Ignition switch
 Harness for short or open between ignition s witch and fuse block (J/B). Refer to PG-11, "
Wiring Diagram -
BATTERY POWER SUPPLY -".
 10A fuse [No.3, located in the fuse block (J/B)]. Refer to PG-143, "
Fuse, Connector and Terminal Arrange-
ment".
 Fuse block (J/B)
Is the inspection result normal?
YES >> Replace heated steering wheel switch. Refer to ST-56, "Removal and Installation".
Heated steering wheel relay Heated steering wheel switch
Continuity
Connector Terminal Connector Terminal
E90 2 M52 2 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 2 Not existed
Fuse block (J/B) Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
M1 2A M52 1 Existed
Fuse block (J/B) GroundContinuity
Connector Terminal
M1 2A Not existed
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

STC-10
< WIRING DIAGRAM >
ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM
WIRING DIAGRAM
ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM
Wiring Diagram INFOID:0000000006256123
JCGWM0392GB
Revision: 2010 May2011 QX56

ELECTRONICALLY CONTROLLED POWER STEERING SYSTEMSTC-11
< WIRING DIAGRAM >
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JCGWM0393GB
Revision: 2010 May2011 QX56