2011 INFINITI QX56 air condition

EC-522
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
SNOW MODE SWITCH
SNOW MODE SWITCH
DescriptionINFOID:0000000006256403
The snow mode switch signal is sent to the combinat
ion meter from the snow mode switch. The combination
meter then sends the signal to the ECM via the CAN communication line.
The snow mode is used for driving or starting the vehicle on snowy roads or slippery areas. If the snow mode
is activated, the vehicle speed will not accelerate as quickly as normal to avoid vehicle slip. In other words,
ECM controls rapid engine torque change by controlling t he electric throttle control actuator operating speed.
Component Function CheckINFOID:0000000006256404
1.CHECK SNOW MODE SWITCH FUNCTION
1. Turn ignition switch ON.
2. Select “SNOW MODE SW” in “DATA MONITOR” mode with CONSULT-III.
3. Check “SNOW MODE SW” indication under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-522, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006256405
1.CHECK DTC WITH COMBINATION METER
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Go to MWI-57, "
Work flow".
2.CHECK SNOW MODE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect snow mode switch harness connector.
3. Turn ignition switch ON.
4. Check the voltage between snow mode switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Fuse block harness connector M3
 10 A fuse (No. 13)
 Harness for open or short between snow mode switch and fuse.
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK SNOW MODE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
Monitor item Condition Indication
SNOW MODE SW Snow mode switch ON ON
OFF OFF
Snow mode switch
Ground Voltage
Connector Terminal
M54 12 Ground Battery voltage
Revision: 2010 May2011 QX56

SNOW MODE SWITCHEC-523
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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2. Disconnect combination meter harness connector.
3. Check the continuity between snow mode switch
harness connector and combination meter harness con-
nector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connector.
5.CHECK SNOW MODE SWITCH
Refer to EC-523, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace snow mode switch. Refer to IP-25, "
Removal and Installation".
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000006256406
1.CHECK SNOW MODE SWITCH
1. Turn ignition switch OFF.
2. Disconnect snow mode s witch harness connector.
3. Check the continuity between snow mode s witch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace snow mode switch. Refer to IP-25, "
Removal and Installation".
Snow mode switch Combination meter
Continuity
Connector Terminal Connector Terminal
M54 22 M34 33 Existed
Terminals Condition Continuity
12 and 22 Snow mode switch ON Existed
OFF Not Existed
Revision: 2010 May2011 QX56

ENGINE CONTROL SYSTEM SYMPTOMSEC-525
< SYMPTOM DIAGNOSIS > [VK56VD]
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Mass air flow sensor circuit
1
12 2
222 2 EC-201
Engine coolant temperature sensor circuit
333
EC-217
Air fuel ratio (A/F) sensor 1 circuit EC-181
EC-228
EC-232
EC-235
EC-238
Throttle position sensor circuit
22EC-219
EC-288
EC-406
EC-407
EC-475
Accelerator pedal position sensor circuit 3 2 1
EC-468EC-471
EC-478
Knock sensor circuit 2 3
EC-297
Engine oil temperature sensor 4 2 3EC-285
Crankshaft position sensor circuit 2 2EC-299
Camshaft position sensor circuit 3 2EC-303
Vehicle speed signal circuit 2 3 3 3EC-356
Power steering pressure sensor circuit 2 3 3EC-371
ECM 22333333333EC-376EC-378
EC-380
Intake valve timing control solenoid valve cir-
cuit
32 13223 3
EC-193
VVEL control module 3 4 4 3 EC-451EC-452
VVEL actuator motor 3 4 4 3
EC-390
VVEL actuator motor relay 3 4 4 3EC-393
VVEL control shaft position sensor 3 4 4 3EC-387
PNP signal circuit 3 3 3 3 3EC-383
Refrigerant pressure sensor circuit 2 3 3 4EC-520
Electrical load signal circuit 3EC-493
Air conditioner circuit 223333333 3 2HAC-60
ABS actuator and electric unit (control unit) 4BRC-60
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: 2010 May2011 QX56

EC-538
< SERVICE DATA AND SPECIFICATIONS (SDS) [VK56VD]
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
Idle SpeedINFOID:0000000006218038
*: Under the following conditions
 A/C switch: OFF
 Electric load: OFF (Lights, heater fan & rear window defogger)
 Steering wheel: Kept in straight-ahead position
Ignition TimingINFOID:0000000006218039
*: Under the following conditions
 A/C switch: OFF
 Electric load: OFF (Lights, heater fan & rear window defogger)
 Steering wheel: Kept in straight-ahead position
Calculated Load ValueINFOID:0000000006218040
Mass Air Flow SensorINFOID:0000000006218041
*: Engine is warmed up to normal operating temperature and running under no load.Condition Specification
No load* (in P or N position) 600 ± 50 rpm
Condition Specification
No load* (in P or N position) 12 ± 2 °BTDC
Condition Specification (U sing CONSULT-III or GST)
At idle 5 – 35%
At 2,500 rpm 5 – 35%
Supply voltageBattery voltage (11 – 14 V)
Output voltage at idle 0.9 – 1.1 V*
Mass air flow (Using CONSULT-III or GST) 1.0 – 5.0 g/s at idle*
7.0 – 20.0 g/s at 2,500 rpm*
Revision: 2010 May2011 QX56

EM-10
< PREPARATION >
PREPARATION
(—)
Pilot bushing pullerRemoving pilot converter
(—)
Valve seat cutter set Finishing valve seat (EXH) dimensions
(—)
Piston ring expander Removing and installing piston ring
(—)
Valve guide drift Removing and installing valve guide (EXH)
a: 9.5 mm (0.374 in) dia.
b: 5.5 mm (0.217 in) dia.
(—)
Valve guide reamer (A): Reaming valve guide (EXH) inner hole
(B): Reaming hole for oversize valve guide
(EXH)
c: 6.0 mm (0.236 in) dia.
d: 10.2 mm (0.402 in) dia.
(J-43897-18)
(J-43897-12)
Oxygen sensor thread cleaner Reconditioning the exhaust system threads be-
fore installing a new heated oxygen sensor (Use
with anti-seize lubricant shown below.)
a: J-43897-18 (18 mm dia.) for zirconia heat-
ed oxygen sensor and air fuel ratio sensor

b: J-43897-12 (12 mm dia.) for titania heated
oxygen sensor and air fuel ratio sensor
(—)
Anti-seize lubricant (Permatex 133AR
or equivalent meeting MIL specifica-
tion MIL-A-907) Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads
(Kent-Moore No.)
Tool name
Description
NT045
S-NT048
S-NT030
JPBIA0400ZZ
JPBIA0401ZZ
AEM488
AEM489
Revision: 2010 May2011 QX56

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGEM-19
< SYMPTOM DIAGNOSIS >
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Use the Chart Below to Help You Find the Cause of the SymptomINFOID:0000000006289523
1. Locate the area where noise occurs.
2. Confirm the type of noise.
3. Specify the operating condition of the engine.
4. Check specified noise source.
If necessary, repair or replace these parts.
A: Closely related B: Related C: Sometimes related —: Not related Location
of noise Type of
noise Operating condition of engine
Source of noise Check item Refer-
ence page
Before
warm- up After
warm- up When
start- ing When
idling When
racing While
driving
Top of en-
gine
Rocker
cover
Cylinder
head Ticking or
clicking
CA—AB— Tappet
noiseValve clearance
EM-12
Rattle C A — A B C Camshaft
bearing
noiseCamshaft runout
Camshaft journal oil
clearance
EM-77
Crank-
shaft pul-
ley
Cylinder
block
(Side of
engine)
Oil panSlap or
knock
—A—B B—
Piston pin
noisePiston to piston pin oil
clearance
Connecting rod bushing
oil clearance
EM-115
Slap or
rap
A——B B A
Piston
slap noisePiston to cylinder bore
clearance
Piston ring side clear-
ance
Piston ring end gap
Connecting rod bend
and torsion
EM-115
Knock A B C B B B
Connect-
ing rod
bearing
noiseConnecting rod bushing
oil clearance
Connecting rod bearing
oil clearance
EM-115
Knock A B — A B C
Main bear-
ing noiseMain bearing oil clear-
ance
Crankshaft runout
EM-115
Front of
engine
Timing
chain caseTapping or
ticking
AA—BBB Timing
chain and
timing
chain ten-
sioner
noiseTiming chain cracks
and wears
Timing chain tensioner
operation
EM-72
Front of
engineSqueak-
ing or fizz-
ing
AB—B—C Drive belts
(Sticking
or slip-
ping)Drive belts deflection
EM-20
CreakingABABAB Drive belts
(Slipping)Idler pulley bearing op-
eration
Squall
Creak AB—BAB Water
pump
noiseWater pump operation
CO-19
Revision: 2010 May2011 QX56

EM-24
< PERIODIC MAINTENANCE >
SPARK PLUG
Install ignition coil marked with an identification mark (A) on
cylinder No. 5, 6, 7 and 8.
InspectionINFOID:0000000006289533
INSPECTION AFTER REMOVAL
Use the standard type spark plug for normal condition.
CAUTION:
 Never drop or impact spark plug.
 Never use a wire brush for cleaning.
 If plug tip is covered with carbon, use spark plug cleaner to clean.
 Measure spark plug gap. When it exceeds the limit, replace spark plug even if it is within the speci-
fied replacement mileage. Refer to EM-132, "
Spark Plug".
 Spark plug gap adjustment is not required between replace-
ment intervals.
: Engine front
JPBIA3471ZZ
Spark plug (Standard type) : Refer to EM-132, "Spark Plug".
Cleaner air pressure : Less than 588 kPa (5.9 bar, 6 kg/cm
2, 85 psi)
Cleaning time : Less than 20 seconds
SMA773C
JPBIA0031ZZ
Revision: 2010 May2011 QX56

AIR CLEANER AND AIR DUCTEM-27
< REMOVAL AND INSTALLATION >
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AIR CLEANER AND AIR DUCT
Exploded ViewINFOID:0000000006289538
Removal and InstallationINFOID:0000000006289539
REMOVAL
NOTE:
Mass air flow sensor is removable under the car-mounted condition.
1. Remove engine cover. Refer to
EM-25, "
Exploded View".
2. Disconnect mass air flow sensor harness connector.
3. Remove air cleaner case and mass air flow sensor assembly and air duct by disconnecting their joints.
 Add matching marks, if necessary for easier installation.
4. Remove mass air flow sensor from air cleaner case, if necessary. CAUTION:
Handle mass air flow sensor accordi ng to the following instructions.
 Never impact it.
 Never disassemble it.
 Never touch its sensor.
5. Disconnect PCV hose from air duct.
6. Remove air duct.
7. Remove air cleaner filter.
8. Remove air cleaner case (lower).
9. Remove adapter.
10. If remove resonator (location in wheel house), refer to following.
a. Remove LH front wheel and tire.
b. Remove fender protector. Refer to EXT-23, "
FENDER PROTECTOR : Exploded View".
c. Remove resonator.
INSTALLATION
1. Resonator 2. Adapter 3. Air cleaner case (lower)
4. Air cleaner filter 5. Air cleaner case (upper) 6. Mass air flow sensor
7. Air duct 8. Clamp
Vehicle front
Refer to GI-4, "
Components" for symbols in the figure.
JPBIA3260GB
Revision: 2010 May2011 QX56