2011 INFINITI QX56 check engine

EC-506
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
IGNITION SIGNAL
IGNITION SIGNAL
Component Function CheckINFOID:0000000006218011
1.INSPECTION START
Turn ignition switch OFF, and restart engine.
Does the engine start?
YES-1 >> With CONSULT-III: GO TO 2.
YES-2 >> Without CONSULT-III: GO TO 3.
NO >> Go to EC-506, "
Diagnosis Procedure".
2.CHECK IGNITION SIGNAL FUNCTION
WITH CONSULT-III
1. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
2. Check that each circuit produces a momentary engine speed drop.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-506, "
Diagnosis Procedure".
3.CHECK IGNITION SIGNAL FUNCTION
WITHOUT CONSULT-III
1. Let engine idle.
2. Read the voltage signal between ECM harness connector terminals under the following conditions with an oscilloscope.
NOTE:
The pulse cycle changes depending on rpm at idle.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-506, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218012
1.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn it ON.
2. Check the voltage between ECM harness connector terminals under the following conditions.
ECM
Voltage signal
Cylinder +–
Connector Terminal Connector Terminal
1
F 111 12
E80 175
213
314
415
517
618
719
820
PBIB0044E
Revision: 2010 May2011 QX56

EC-510
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
IGNITION SIGNAL
3. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
 For the fuse number, refer to EC-114, "
Wiring Diagram".
 For the fuse arrangement, refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
 Do not use CONSULT-III to release fuel pressure , or fuel pressure applies again during the following
procedure.
4. Start engine.
5. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
6. Turn ignition switch OFF.
7. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
8. Remove ignition coil and spark plug of the cylinder to be checked.
9. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
10. Connect spark plug and harness connector to ignition coil.
11. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
12. Crank engine for approximately 3 seconds, and check whether
spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
 Never place the spark plug and the ignition coil within 50
cm (19.7 in) each other. Be careful not to get an electrical
shock while checking, becau se the electrical discharge
voltage becomes 20 kV or more.
 It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
NOTE:
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace malfunctioning ignition coil with power transistor.
Component Inspection (Condenser)INFOID:0000000006218014
1.CHECK CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace condenser. Spark should be generated.
JMBIA0066GB
Terminals Resistance
1 and 2 Above 1 M Ω [at 25 °C (77 °F)]
Revision: 2010 May2011 QX56

INFORMATION DISPLAY (ASCD)EC-511
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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EC
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INFORMATION DISPLAY (ASCD)
Component Function CheckINFOID:0000000006218015
1.CHECK INFORMATION DISPLAY
1. Start engine.
2. Press MAIN switch on ASCD steering switch.
3. Drive the vehicle at more than 40 km/h (25 MPH). CAUTION:
Always drive vehicle at a safe speed.
4. Press SET/COAST switch.
5. Check that the reading of the speedom eter shows the same value as the set speed indicated in the infor-
mation display while driving the vehicle on a flat road.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-511, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218016
1.CHECK DTC
Check that DTC UXXXX or P0500 is not displayed.
Is the inspection result normal?
YES >> GO TO 2.
NO-1 >> Perform trouble diagnosis for DTC UXXXX.
NO-2 >> Perform trouble diagnosis for DTC P0500. Refer to EC-356, "
DTC Logic".
2.CHECK DTC WITH “COMBINATION METER”
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for DTC indicated.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace combination meter.
NO >> Repair or replace.
Revision: 2010 May2011 QX56

EC-520
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Component Function CheckINFOID:0000000006218026
1.CHECK REFRIGERANT PRESSURE SENSOR FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-520, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218027
1.CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressu re sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between refrigerant pressure sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and refrigerant pressure sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between refrigerant pre ssure sensor harness connector and ECM harness connec-
tor.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
ECM Voltage (V)
Connector +–
Terminal Terminal
E80 144
(Refrigerant pressure sensor signal) 150 1.0 - 4.0
Refrigerant pressure sensor
Ground Voltage (V)
Connector Terminal
E77 1 Ground Approx. 5
Refrigerant pressure sensor ECM Continuity
Connector Terminal Connector Terminal
E77 3 E80 150 Existed
Revision: 2010 May2011 QX56

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

EC-532
< PERIODIC MAINTENANCE >[VK56VD]
EVAP LEAK CHECK
EVAP LEAK CHECK
InspectionINFOID:0000000006267340
CAUTION:
 Do not use compressed air or a high pressure pump.
 Do not exceed 4.12 kPa (0.042 kg/cm
2, 0.6 psi) of pressure in EVAP system.
NOTE:
 Do not start engine.
 Improper installation of EVAP service port adapter (com mercial service tool) to the EVAP service port may
cause a leak.
WITH CONSULT-III
1. To locate the EVAP leak, install EVAP service port adapter (com- mercial service tool) and pressure pump to EVAP service port.
2. Turn ignition switch ON.
3. Select the “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-III.
4. Touch “START”. A bar graph (Pressure indicating display) will appear on the screen.
5. Apply positive pressure to the EVAP system until the pressure indicator reaches the middle of the bar graph.
6. Remove EVAP service port adapter (commercial service tool) and hose with pressure pump.
7. Locate the leak using a leak detector (commercial service tool). Refer to EC-45, "
EVAPORATIVE EMISSION SYSTEM : System
Diagram".
WITHOUT CONSULT-III
1. To locate the EVAP leak, install EVAP service port adapter (com-
mercial service tool) and pressure pump to EVAP service port.
2. Apply battery voltage between the terminals of EVAP canister vent control valve to ma ke a closed EVAP system.
3. To locate the leak, deliver positive pressure to the EVAP system until pressure gauge points reach 1.38 to 2.76 kPa (0.014 to
0.028 kg/cm
2, 0.2 to 0.4 psi).
4. Remove EVAP service port adapter (commercial service tool) and hose with pressure pump.
SEF462UA
SEF200U
SEF462UA
Revision: 2010 May2011 QX56

EC-534
< PERIODIC MAINTENANCE >[VK56VD]
POSITIVE CRANKCASE VENTILATION
POSITIVE CRANKCASE VENTILATION
InspectionINFOID:0000000006218033
1.CHECK PCV VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace PCV valve. Refer to EM-33, "
Exploded View".
PBIB1589E
Revision: 2010 May2011 QX56

EM-1
ENGINE
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SECTION EM
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CONTENTS
ENGINE MECHANICAL
PRECAUTION ................ ...............................3
PRECAUTIONS .............................................. .....3
Precaution for Procedure without Cowl Top Cover ......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
Precaution for Drain Engine Coolant and Engine
Oil ..............................................................................
4
Precaution for Disconnecting Fuel Piping .................4
Precaution for Handling High Pressure Fuel Sys-
tem ............................................................................
4
Precaution for Removal and Disassembly ................4
Precaution for Inspection, Repair and Replace-
ment ..........................................................................
4
Precaution for Assembly and Installation ..................4
Parts Requiring Angle Tightening .............................5
Precaution for Liquid Gasket .....................................5
Definitions of Bank Names ........................................6
PREPARATION ............................................7
PREPARATION .............................................. .....7
Special Service Tool ........................................... ......7
Commercial Service Tool ..........................................9
BASIC INSPECTION ...................................12
CAMSHAFT VALVE CLEARANCE ............... ....12
Inspection ............................................................ ....12
COMPRESSION PRESSURE ............................16
Inspection ............................................................ ....16
SYMPTOM DIAGNOSIS ..............................18
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ ....
18
NVH Troubleshooting - Engine Noise .............. ....18
Use the Chart Below to Help You Find the C
ause of the Symptom ........................................ ....
19
PERIODIC MAINTENANCE ........................20
DRIVE BELTS ...................................................20
Exploded View ..................................................... ....20
Checking ..................................................................20
Tension Adjustment ................................................20
Removal and Installation .........................................20
Inspection ................................................................21
AIR CLEANER FILTER .....................................22
Exploded View .........................................................22
Removal and Installation .........................................22
SPARK PLUG ...................................................23
Exploded View .........................................................23
Removal and Installation .........................................23
Inspection ................................................................24
REMOVAL AND INSTALLATION ...............25
ENGINE COVER ...............................................25
Exploded View ..................................................... ....25
Removal and Installation .........................................25
DRIVE BELT AUTO TENSIONER AND IDLER
PULLEY .............................................................
26
Exploded View .........................................................26
Removal and Installation .........................................26
AIR CLEANER AND AIR DUCT .......................27
Exploded View .........................................................27
Removal and Installation .........................................27
Inspection ................................................................28
IGNITION COIL .................................................29
Exploded View .........................................................29
Removal and Installation .........................................29
INTAKE MANIFOLD .........................................30
Exploded View .........................................................30
Revision: 2010 May2011 QX56