air condition INFINITI QX56 2011 Factory Service Manual

DIAGNOSIS AND REPAIR WORK FLOWST-13
< BASIC INSPECTION >
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORK FLOW
WorkFlow (Heated Steering Wheel)INFOID:0000000006225583
DETAILED FLOW
1.OBTAIN INFORMATION ABOUT SYMPTOM
Interview the customer to obtain the malfunction information (conditions and environment when the malfunc-
tion occurred) as much as possible when the customer brings the vehicle in.
>> GO TO 2.
2.REPRODUCE THE MALFUNCTION INFORMATION
Check the malfunction on the vehicl e that the customer describes.
Inspect the relation of the symptoms and the condition when the symptoms occur.
>> GO TO 3.
3.IDENTIFY THE MALFUNCTIONING SYST EM WITH “SYMPTOM DIAGNOSIS”
Use “Symptom diagnosis” from the symptom inspection re sult in step 2 and then identify where to start per-
forming the diagnosis based on possible causes and symptoms.
>> GO TO 4.
4.IDENTIFY THE MALFUNCTIONING PART S WITH “COMPONENT DIAGNOSIS”
Perform the diagnosis with “Component di agnosis” of the applicable system.
>> GO TO 5.
5.REPAIR OR REPLACE THE MALFUNCTIONING PARTS
Repair or replace the specified malfunctioning parts.
>> GO TO 6.
6.FINAL CHECK
Check that malfunctions are not reproduced when obtai ning the malfunction information from the customer,
referring to the symptom inspection result in step 2.
Are the malfunctions corrected?
YES >> INSPECTION END
NO >> GO TO 2.
Revision: 2010 May2011 QX56

ST-16
< DTC/CIRCUIT DIAGNOSIS >
HEATED STEERING WHEEL SYSTEM
DTC/CIRCUIT DIAGNOSIS
HEATED STEERING WHEEL SYSTEM
Component Function CheckINFOID:0000000006225585
1.CHECK HEATED STEERING WHEEL SYSTEM
Check operate heated steering wheel system. Refer to ST-9, "
System Description (Heated Steering Wheel)".
Is the inspection result normal?
YES >> Go to ST-16, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006225586
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

ST-18
< DTC/CIRCUIT DIAGNOSIS >
HEATED STEERING WHEEL SYSTEM
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 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 (Heated Steering Wheel)INFOID:0000000006225587
1.CHECK HEATED STEERING WHEEL CONTINUITY
Check continuty between heated steering wheel connector terminals.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace heated steering wheel. Refer to ST-33, "
Removal and Installation".
2.CHECK HEATED STEERING WHEEL RESISTANCE
Check resistance between heated steering wheel connector terminals.
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
heated steering wheel Condition Continuity
Terminal
1 − 2 Leather surface temperature of
20
°C (68 °F) or less Existed
Leather surface temperature of
30 °C (86 °) or more Not existed
heated steering wheel
Condition Resistance (Apprx.)
Terminal
1 − 2 Leather surface temperature of
20
°C (68 °F) 1.83
Ω
Revision: 2010 May2011 QX56

ST-20
< DTC/CIRCUIT DIAGNOSIS >
HEATED STEERING WHEEL SWITCH INDICATOR LAMP
HEATED STEERING WHEEL SWITCH INDICATOR LAMP
Component Function CheckINFOID:0000000006225589
1.CHECK HEATED STEERING WHEEL INDICATOR LAMP
1. Turn ignition switch ON.
2. Turn heated steering wheel switch ON.
Does heated steering wheel indicator lamp turn on the lamp?
YES >> GO TO 2.
NO >> Go to ST-20, "
Diagnosis Procedure".
2.CHECK HEATED STEERING WHEEL INDICATOR LAMP
Turn heated steering wheel switch OFF.
Does heated steering wheel indicator lamp turn off the lamp?
YES >> INSPECTION END
NO >> Go to ST-20, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006225590
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-33, "
Removal and Installation".
4. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
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
Revision: 2010 May2011 QX56

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

HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
ST-23
< 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

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

STEERING GEAR AND LINKAGEST-47
< REMOVAL AND INSTALLATION >
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 Hook a spring balance at the point shown in the figure and pull the spring balance. Make sure that the spring balance reads the spec-
ified value when ball stud and inner socket start to move. Replace
outer socket and inner socket if they are outside the standard.
BALL JOINT ROTATING TORQUE
 Make sure that the reading is within the following specified rangeusing preload gauge (A) [SST: ST3127S000 (J-25765-A)]. Replace
outer socket if the reading is outside the specified value.
BALL JOINT AXIAL END PLAY
 Apply an axial load of 490 N (50 kg, 110 lb) to ball stud. Using adial gauge, measure amount of stud movement, and then make
sure that the value is within the following specified range. Replace
outer socket (1) and inner socket (2) if the measured value is out-
side the standard.
INSPECTION AFTER INSTALLATION
 After installation, bleed air from the steering hydraulic system. Refer to ST-30, "Inspection".
 Check if steering wheel turns smoothly when it is turned several times fully to the end of the left and right.
 Check the steering wheel play, neutral position steeri ng wheel, steering wheel turning force, and front wheel
turning angle. Refer to ST-32, "
Inspection".
 Check the fluid level, fluid leakage, and air bleeding hydraulic system. Refer to ST-30, "
Inspection".
 Perform final tightening of nuts and bolts on each part under unladen conditions with tires on level ground when removing steering gear assembly. Check wheel alignment. Refer to FSU-7, "
Inspection".
 Adjust neutral position of steering angle sensor after checking wheel alignment. Refer to BRC-64, "
Work
Procedure".
Outer socket
(Measuring point: Stud cotter pin mounting hole)
Spring balance measure-
ment : Refer to
ST-58, "
Socket
Swing Force and Rotating
To r q u e".
Inner socket (Measuring point: “*” mark shown in the figure)
Spring balance measure-
ment : Refer to
ST-58, "
Socket
Swing Force and Rotating
To r q u e".
Outer socket rotat-
ing torque : Refer to
ST-58, "
Socket Swing
Force and Rotating Torque".
SGIA0896E
SGIA1382E
Outer socket : Refer to ST-58, "Socket Axial End Play".
Inner socket : Refer to ST-58, "
Socket Axial End Play".
JSGIA0109ZZ
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