ignition INFINITI QX56 2011 Factory Service Manual

HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
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< SYMPTOM DIAGNOSIS >
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SYMPTOM DIAGNOSIS
HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
Description INFOID:0000000006225592
 The heated steering wheel does not warm up.
 The heated steering wheel system cannot be turned OFF.
Diagnosis ProcedureINFOID:0000000006225593
1.CHECK POWER SOURCE AND GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Remove the heated steering wheel. Refer to ST-33, "
Removal and Installation".
3. Turn ignition switch ON.
CAUTION:
Never start the engine.
4. Turn heated steering wheel switch ON.
5. Check voltage between heated steering wheel harness connector terminals.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK HEATED STEERING WHEEL
Check heated steering wheel. Refer to ST-18, "
Component Inspection (Heated Steering Wheel)".
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace heated steering wheel. Refer to ST-33, "
Removal and Installation".
3.CHECK GROUND CIRCUIT
Check continuity between heated steering wheel harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
1. Turn ignition switch OFF.
2. Disconnect heated steering wheel relay connector. Refer to ST-7, "
Component Parts Location (Heated
Steering Wheel)".
3. Disconnect heated steering wheel switch connector. Refer to ST-56, "
Removal and Installation"
4. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel harness connector terminal.
Heated steering wheel Condition Voltage (Approx.)
Connector Terminal
M303 1 − 2 Within 30 minutes after
turning ON the heated
steering switch.
Battery voltage
Other conditions. 0 V
Heated steering wheel GroundContinuity
Connector Terminal
M303 2 Existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
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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

ST-26
< SYMPTOM DIAGNOSIS >
HEATED STEERING WHEEL SWITCH INDICATOR LAMP DOES NOT TURN ON
HEATED STEERING WHEEL SWITCH INDICATOR LAMP DOES NOT
TURN ON
Description INFOID:0000000006225594
 Heated steering wheel switch indicator lamp does not turn on the lamp.
 Heated steering wheel switch indicator lamp does not turn off the lamp.
Diagnosis ProcedureINFOID:0000000006225595
1.CHECK POWER SOURCE AND GROUND CIRCUIT
1. Turn ignition switch ON. CAUTION:
Never start the engine.
2. Turn heated steering wheel switch ON.
3. Check voltage between heated steering wheel switch harness connector terminals.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK GROUND CIRCUIT
Check continuity between heated steering wheel switch harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
SWITCH
1. Turn ignition switch OFF.
2. Disconnect heated steering wheel relay connector. Refer to ST-7, "
Component Parts Location (Heated
Steering Wheel)".
3. Disconnect heated steering wheel switch connector. Refer to ST-56, "
Removal and Installation".
4. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
5. Check continuity between heated steering w heel relay harness connector terminal and ground.
Heated steering wheel
Condition Voltage (Approx.)
Connector Terminal
M52 5 − 6 Within 30 minutes after
turning ON the heated
steering switch.
Battery voltage
Other conditions. 0 V
Heated steering wheel switch GroundContinuity
Connector Terminal
M52 6 Existed
Heated steering wheel relay Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
E90 5 M52 5 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 5 Not existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SWITCH INDICATOR LAMP DOES NOT TURN ON
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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-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
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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

SYSTEMSTC-7
< SYSTEM DESCRIPTION >
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Error area and root cause Cancel condition
Engine speed is 1,500 rpm or more and there is no vehicle speed signal input for
over 10 seconds during vehicle travel.  When a vehicle speed signal of 2 km/h (1.2
MPH) or more is inputted.
 Ignition switch is turned OFF to ON.
Vehicle speed signal has abruptly dropped from 30 km/h (19 MPH) or more to 2
km/h (1.2 MPH) or less within 1.4 seconds.
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

POWER STEERING CONTROL UNITSTC-9
< ECU DIAGNOSIS INFORMATION >
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When using circuit tester or osci lloscope to measure voltage for in spection, be sure not to forcibly
extend any connector terminals.
Fail-Safe INFOID:0000000006256122
EPS system
 EPS system enters the fail-safe mode (that allows the steering
force to be controlled without impair ing the drivability) if any of the
input/output values to/from EPS system (power steering control
unit) deviate from the standard range.
 The power steering control unit controls the driving voltage to the
power steering solenoid valve for maintaining the power steering
assist force when the fail-safe function is activated. (The engine
speed signals control EPS system if any vehicle speed signal error
is detected.)
10
(B/SB) Ground Engine speed signal Input Engine is running
 Warm-up condition
 Idle speed
Engine is running
 Warm-up condition
 Engine speed: Approx. 2,000
rpm
Te r m i n a l N o .
(Wire color) Description
Condition Value (Approx.)
+ - Signal name Input/
OutputJPBIA3352ZZ
JPBIA3354ZZ
JPGIB0022GB
Error area and root cause Cancel condition
Engine speed is 1,500 rpm or more and there is no vehicle speed signal input for
over 10 seconds during vehicle travel.  When a vehicle speed signal of 2 km/h (1.2
MPH) or more is inputted.
 Ignition switch is turned OFF to ON.
Vehicle speed signal has abruptly dropped from 30 km/h (19 MPH) or more to 2
km/h (1.2 MPH) or less within 1.4 seconds.
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