2011 INFINITI QX56 ignition

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

IGNITION SIGNALEC-507
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Is the inspection result normal?
YES >> GO TO 2.
NO >> Go to
EC-168, "
Diagnosis Procedure".
2.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Turn ignition switch ON.
4. Check the voltage between condenser harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 3.
3.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E7.
3. Check the continuity between IPDM E/R harness connector and condenser harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> Go to EC-168, "Diagnosis Procedure".
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between IPDM E/R and condenser
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between condenser harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
ECM
Vo l ta g e
Connector +–
Terminal Terminal
E80 171
175 Battery voltage
172
Condenser Ground Voltage
Connector Terminal
F8 1 Ground Battery voltage
IPDM E/R Condenser Continuity
Connector Terminal Connector Terminal
E15 61 F8 1 Existed
Condenser Ground Continuity
Connector Terminal
F8 2 Ground Existed
Revision: 2010 May2011 QX56

EC-508
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
IGNITION SIGNAL
YES >> GO TO 6.
NO >> Repair open circuit or short to power in harness or connectors.
6.CHECK CONDENSER
Refer to EC-510, "
Component Inspection (Condenser)"
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace condenser.
7.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV
1. Reconnect all harness connectors disconnected.
2. Disconnect ignition coil harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ignition coil harness connector and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
 Harness connector F22 and E46
 Harness for open or short between ignition coil and harness connector F22
>> Repair or replace harness or connectors.
9.CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between ignition coil harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
Ignition coil Ground Voltage
Cylinder Connector Terminal
1F75 3
Ground Battery voltage
2F76 3
3F77 3
4F78 3
5F79 3
6F80 3
7F81 3
8F82 3
Ignition coil
Ground Continuity
Cylinder Connector Terminal
1F75 2
Ground Existed
2F76 2
3F77 2
4F78 2
5F79 2
6F80 2
7F81 2
8F82 2
Revision: 2010 May2011 QX56

IGNITION SIGNALEC-509
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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YES >> GO TO 10.
NO >> Repair open circuit or short to power in harness or connectors.
10.CHECK IGNITION COIL OUTPUT SI
GNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between ignition coil harness connector and ECM harness connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 11.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
11 .CHECK IGNITION COIL WITH POWER TRANSISTOR
Refer to EC-509, "
Component Inspection (Ignition Coil with Power Transistor)".
Is the inspection result normal?
YES >> GO TO 12.
NO >> Replace malfunctioning ignition coil with power transistor.
12.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Ignition Coil with Power Transistor)INFOID:0000000006218013
1.CHECK IGNITION COIL WITH POWER TRANSISTOR-I
1. Turn ignition switch OFF.
2. Disconnect ignition coil harness connector.
3. Check resistance between ignition coil terminals as per the following.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace malfunctioning ignition coil with power transistor.
2.CHECK IGNITION COIL WITH POWER TRANSISTOR-II
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
Ignition coil ECM Continuity
Cylinder Connector Terminal Connector Terminal
1F75 1
F 11112
Existed
2F76 1 13
3F77 1 14
4F78 1 15
5F79 1 17
6F80 1 18
7F81 1 19
8F82 1 20
Terminals Resistance [at 25
°C (77 °F)]
1 and 2 Except 0 or ∞ Ω
1 and 3 Except 0 Ω
2 and 3
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

EC-512
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
LOW PRESSURE FUEL PUMP
LOW PRESSURE FUEL PUMP
Component Function CheckINFOID:0000000006218017
1.CHECK FUEL PUMP FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers. NOTE:
Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned ON.
Is the inspection result normal?
YES >> INSPECTION END
NO >> EC-512, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218018
1.CHECK FPCM POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect FPCM harness connector.
3. Turn ignition switch ON.
4. Check the voltage between FPCM 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 FPCM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between FPCM harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit or short to power in harness or connectors.
3.CHECK FPCM INPUT AND OUTPUT CIRCUIT
1. Disconnect ECM harness connector.
2. Check the continuity between FPCM harness connector and ECM harness connector.
3. Also check harness for short to ground and to power.
Is the inspection result normal?
+ −Voltag e
FPCM
Connector Terminal B41 10 Ground Battery voltage
+ −Continuity
FPCM
Connector Terminal B41 5 Ground Existed
+ −
Continuity
FPCM ECM
Connector Terminal Connector Terminal
B41 8
E80 125
Existed
9142
Revision: 2010 May2011 QX56

LOW PRESSURE FUEL PUMPEC-513
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK FUEL PUMP CONTROL CIRCUIT
1. Disconnect fuel level sensor unit and fuel pump harness connector.
2. Check the continuity between FPCM harness connecto r and fuel level sensor unit and fuel pump harness
connector.
3. Also check harness for short to ground and to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK LOW PRESSURE FUEL PUMP
Refer to EC-513, "
Component Inspection (Low Pressure Fuel Pump)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-5, "
Removal and Installation".
6.CHECK FPCM
Refer to EC-514, "
Component Inspection (FPCM)".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace FPCM. Refer to EC-537, "
Removal and Installation".
Component Inspection (Low Pressure Fuel Pump)INFOID:0000000006218019
1.CHECK FUEL PRESSURE REGULATOR
1. Turn ignition switch OFF.
2. Check low fuel pressure. Refer to EC-153, "
Work Procedure".
Is inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK LOW PRESSURE FUEL PUMP
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump.
3. Check resistance between fuel level sens or unit and fuel pump terminals as follows.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-5, "
Removal and Installation".
+−
Continuity
FPCM Fuel level sensor unit and fuel pump
Connector Terminal Connector Terminal
B41 6
C5 3
Existed
71
+ −
Condition Resistance
Fuel level sensor unit and fuel
pump
Te r m i n a l s
1 3 Temperature: 25 °C (77 °F) 0.2 - 5.0 Ω
Revision: 2010 May2011 QX56

EC-514
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
LOW PRESSURE FUEL PUMP
Component Inspection (FPCM)
INFOID:0000000006218020
1.CHECK FUEL PUMP CONTROL MODULE (FPCM)
1. Check the voltage between FPCM terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace FPCM. Refer to EC-537, "
Removal and Installation".
FPCM
Condition Voltage
+ −
Te r m i n a l Te r m i n a l
76 For 1 second after
turning ignition
switch ON Approx. 8.5 V
More than 1 seco nd after turning
ignition switch ON Approx. 0 V
Idle speed Approx. 8.5 V
Revision: 2010 May2011 QX56