2011 INFINITI QX56 engine

ELECTRICALLY-CONTROLLED COOLING FAN COUPLINGEC-495
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
Component Function CheckINFOID:0000000006217997
1.CHECK COOLING FAN FUNCTION
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage.
NOTE:
Speed changes gradually as the percentage changes.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98°C (209 °F).
2. Check that cooling fan speed increase.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-495, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217998
1.CHECK DRIVE BELT
1. Turn ignition switch OFF.
2. Check that the drive belt is not broken.
Is inspection result normal?
YES >> GO TO 2.
NO >> Replace drive belt.
2.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING POWER SUPPLY
1. Disconnect electrically-controlled c ooling fan coupling harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for power supply circuit.
3.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between electrically-cont rolled cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL SIGNAL
WITH CONSULT-III
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector TerminalF39 1 Ground Battery voltage
+ −Continuity
Electrically-controlled cooling fan coupling
Connector TerminalF39 6 Ground Existed
Revision: 2010 May2011 QX56

EC-496
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIV
E TEST” mode of “ECM” with CONSULT-III.
3. Set the Duty value to 100%.
4. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
CAUTION:
Wait for 1 minute or more to measure.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98 °C (209 °F).
2. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
CAUTION:
Wait for 1 minute or more to measure.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 5.
5.CHECK ELECTRICALLY-CONTROLLED COOL ING FAN COUPLING CONTROL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector.
3. Check the continuity between electrically-contro lled cooling fan coupling harness connector and IPDM E/
R harness connector.
4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 6.
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector Terminal
F39 3 Ground 2. 5 V
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector Terminal
F39 3 Ground 2. 5 V
JMMIA0404GB
JMMIA0404GB
+−
Continuity
Electrically-controlled cooling fan
coupling IPDM E/R
Connector Terminal Connector Terminal F39 3 E17 72 Existed
Revision: 2010 May2011 QX56

EC-498
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
FUEL INJECTOR
FUEL INJECTOR
Component Function CheckINFOID:0000000006218002
1.INSPECTION START
Turn ignition switch to START.
Are any cylinders ignited?
YES >> GO TO 2.
NO >> Proceed to EC-498, "
Diagnosis Procedure".
2.CHECK FUEL INJECTOR FUNCTION
WITH CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Check that each circuit produces a momentary engine speed drop.
WITHOUT CONSULT-III
1. Start engine.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-498, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218003
1.CHECK FUEL INJECTOR POWER SUPPLY
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "
Diagnosis Procedure".
2.CHECK FUEL INJECTOR CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel injector harness connector and ECM harness connector.
3. Check the continuity between fuel inje ctor harness connector and ECM harness connector.
Clicking sound should be heard.
PBIB3332E
+
−Voltag e
ECM
Connector Terminal
F 111 46
Ground Battery voltage
51
E80 111
11 2
Revision: 2010 May2011 QX56

HIGH PRESSURE FUEL PUMPEC-501
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
HIGH PRESSURE FUEL PUMP
Component Function CheckINFOID:0000000006218005
1.CHECK HIGH PRESSURE FUEL PUMP FUNCTION
WITH CONSULT-III
1. Start engine.
2. Check “FUEL PRES SEN V” in “D ATA MONITOR” mode with CONSULT-III.
WITHOUT CONSULT-III
1. Start engine.
2. Check the voltage between ECM harness connector and ground.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-501, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218006
1.CHECK HIGH PRESSURE FUEL PUMP SOLENOID CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector and high pressure fuel pump harness connector.
3. Check the continuity between ECM harness connector and high pressure fuel pump harness connector.
Monitor Item Condition Values/Status
FUEL PRES SEN V Engine speed: Idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm
quickly
1,100 – 2,900 mV
ECM
Condition Voltage
+ −
Connector Terminal Connector Terminal
F110 105 E80 175 [Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
JPBIA3340ZZ
JPBIA3341ZZ
+
−
Continuity
ECM High pressure fuel pump
Connector Terminal Connector Terminal
F110 105
F24 1
Existed
11 0 2
Revision: 2010 May2011 QX56

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]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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