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![INFINITI QX56 2011 Factory Service Manual
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 fus INFINITI QX56 2011 Factory Service Manual
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 fus](/manual-img/42/57033/w960_57033-2533.png)
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
Page 2578 of 5598

EM-16
< BASIC INSPECTION >
COMPRESSION PRESSURE
COMPRESSION PRESSURE
InspectionINFOID:0000000006289521
1. Warm up engine thoroughly. Then, stop it.
2. Release fuel pressure. Refer to EC-153, "
Work Procedure".
CAUTION:
If CONSULT-III is not used to release fuel pr essure leave the fuel pump fuse disconnected until
step 7.
3. Remove fuel pump fuse in IPDM E/R. NOTE:
For the fuse number, refer to EC-114, "
Wiring Diagram".
For the fuse arrangement, refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
4. Remove engine cover. Refer to EM-25, "
Exploded View".
5. Remove ignition coil and spark plug from each cylinder. Refer to EM-29, "
Exploded View".
6. Connect engine tachometer (not required in use of CONSULT-III).
7. Install the compression tester with Tool [SST: EG15050500 (J- 45402)] into the spark plug hole.
8. Measure compression pressure using compressi on gauge connected with flexible type adapter (commer-
cial service tool).
9. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each
cylinder.
CAUTION:
Measure a six-cylinder under the same conditio ns since a measurement depends on measure-
ment conditions (engine water temperature, etc.).
Always use a fully changed battery to obtain the specified engine speed.
If the engine speed is out of the specified range, c heck battery liquid for proper gravity. Check the
engine speed again with normal battery gravity. Refer to PG-159, "
How to Handle Battery".
If compression pressure is below the minimum value, check valve clearances and parts associated with combustion chamber (valve, valve seat, piston, pi ston ring, cylinder bore, cylinder head, cylinder head
gasket). After checking, measure compression pressure again.
If a cylinder has low compression pressure, pour a small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression.
- If the added engine oil improves the compression, pi ston rings may be worn out or damaged. Check pis-
ton rings and replace if necessary. Refer to EM-107, "
Disassembly and Assembly".
- If the compression pressure remains at low level despite the addition of engine oil, valves may be mal- functioning. Check valves for damage. Replace valve or valve seat accordingly. Refer to EM-107, "
Dis-
assembly and Assembly".
If two adjacent cylinders have respectively low co mpression pressure and their compression remains
low even after the addition of engine oil, cylinder head gaskets are leaking. In such a case, replace cyl-
inder head gaskets. Refer to EM-87, "
Removal and Installation".
10. After inspection is completed, install removed parts.
11. Start the engine, and check that the engine runs smoothly.
WBIA0605E
Compression pressure : Refer to EM-132, "GeneralSpecification".
Revision: 2010 May2011 QX56
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EXL-2
EXTERIOR LAMP BATTERY SAVER SYSTEM :
System Description .................................................
21
DIAGNOSIS SYSTEM (BCM) ............................22
COMMON ITEM ..................................................... ...22
COMMON ITEM : CONSULT-III Function (BCM -
COMMON ITEM) ................................................. ...
22
HEADLAMP ........................................................... ...23
HEADLAMP : CONSULT-III Function (BCM -
HEAD LAMP) ..........................................................
23
FLASHER ............................................................... ...25
FLASHER : CONSULT-III Function (BCM -
FLASHER) ..............................................................
25
DIAGNOSIS SYSTEM (IPDM E/R) ....................27
Diagnosis Description .......................................... ...27
CONSULT-III Function (IPDM E/R) ........................29
DIAGNOSIS SYSTEM (AFS) .............................32
CONSULT-III Function (ADAPTIVE LIGHT) ........ ...32
ECU DIAGNOSIS INFORMATION ..............34
BCM, IPDM E/R .............................................. ...34
List of ECU Reference ......................................... ...34
AFS CONTROL UNIT ........................................35
Reference Value .................................................. ...35
Fail-Safe .................................................................38
DTC Inspection Priority Chart .................................39
DTC Index ..............................................................39
WIRING DIAGRAM .....................................40
EXTERIOR LIGHTING SYSTEM .................... ...40
Wiring Diagram .................................................... ...40
BASIC INSPECTION ...................................59
DIAGNOSIS AND REPAIR WORKFLOW ...... ...59
Work Flow ............................................................ ...59
INSPECTION AND ADJUSTMENT ...................61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) .............. ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) : De-
scription ..................................................................
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) : Special
Repair Requirement ...............................................
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) ................... ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) : Descrip-
tion ....................................................................... ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) : Special
Repair Requirement ............................................. ...
61
LEVELIZER ADJUSTMENT ......................................61
LEVELIZER ADJUSTMENT : Description ..............61
LEVELIZER ADJUSTMENT : Special Repair Re-
quirement ............................................................. ...
61
DTC/CIRCUIT DIAGNOSIS ........................63
B2503, B2504 SWIVEL ACTUATOR ............. ...63
DTC Logic ............................................................ ...63
Diagnosis Procedure ...............................................64
Component Inspection ............................................67
B2513 HEIGHT SENSOR UNUSUAL [FR] .......68
DTC Logic ............................................................ ...68
Diagnosis Procedure ...............................................68
B2514 HEIGHT SENSOR UNUSUAL [RR] .......71
DTC Logic ............................................................ ...71
Diagnosis Procedure ...............................................71
B2516 SHIFT SIGNAL [P, R] ............................74
DTC Logic ............................................................ ...74
Diagnosis Procedure ...............................................74
B2517 VEHICLE SPEED SIGNAL ....................75
DTC Logic ............................................................ ...75
Diagnosis Procedure ...............................................75
B2519 LEVELIZER CALIBRATION ..................76
DTC Logic ............................................................ ...76
Diagnosis Procedure ...............................................76
B2521 ECU CIRCUIT ........................................77
DTC Logic ............................................................ ...77
Diagnosis Procedure ...............................................77
C0126 STEERING ANGLE SENSOR SIGNAL ...80
DTC Logic ............................................................ ...80
Diagnosis Procedure ...............................................80
C0428 STEERING ANGLE SENSOR CALI-
BRATION ...........................................................
81
DTC Logic ............................................................ ...81
Diagnosis Procedure ...............................................81
U1000 CAN COMM CIRCUIT ............................82
Description ........................................................... ...82
DTC Logic ...............................................................82
Diagnosis Procedure ...............................................82
U1010 CONTROL UNIT (CAN) .........................83
DTC Logic ............................................................ ...83
Diagnosis Procedure ...............................................83
POWER SUPPLY AND GROUND CIRCUIT .....84
AFS CONTROL UNIT ............................................. ...84
AFS CONTROL UNIT : Diagnosis Procedure .........84
Revision: 2010 May2011 QX56
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EXL-40
< WIRING DIAGRAM >[XENON TYPE]
EXTERIOR LIGHTING SYSTEM
WIRING DIAGRAM
EXTERIOR LIGHTING SYSTEM
Wiring DiagramINFOID:0000000006213921
JCLWM5436GB
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EXTERIOR LIGHTING SYSTEMEXL-41
< WIRING DIAGRAM > [XENON TYPE]
C
D
E
F
G H
I
J
K
M A
B
EXL
N
O P
JCLWM5437GB
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EXL-42
< WIRING DIAGRAM >[XENON TYPE]
EXTERIOR LIGHTING SYSTEM
JCLWM5438GB
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EXTERIOR LIGHTING SYSTEMEXL-43
< WIRING DIAGRAM > [XENON TYPE]
C
D
E
F
G H
I
J
K
M A
B
EXL
N
O P
JCLWM5439GB
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EXL-44
< WIRING DIAGRAM >[XENON TYPE]
EXTERIOR LIGHTING SYSTEM
JCLWM5440GB
Revision: 2010 May2011 QX56