2009 INFINITI QX56 crankshaf

EC-424
< ECU DIAGNOSIS >[VK56DE]
ECM
13 OCrankshaft position sensor
(POS) [Engine is running]

Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle Approximately 10V
[Engine is running]
 Engine speed: 2,000 rpm Approximately 10V
14 Y Camshaft position sensor
(PHASE) [Engine is running]

Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle 1.0 - 4.0V
[Engine is running]
 Engine speed: 2,000 rpm 1.0 - 4.0V
15 W Knock sensor (bank 1) [Engine is running]
 Idle speedApproximately 2.5V
16 G/L A/F sensor 1 (bank 1) [Engine is running]

Warm-up condition
 Engine speed: 2,000 rpm Approximately 1.8V
Output voltage varies with air fuel
ratio.
TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)PBIB1041E
PBIB1042E
PBIB1039E
PBIB1040E
Revision: December 20092009 QX56

ECM
EC-455
< ECU DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
DTC Inspection Priority ChartINFOID:0000000003771736
If some DTCs are displayed at the same time, per
form inspections one by one based on the following priority
chart.
NOTE:
 If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P0607 is displayed with ot her DTC, first perform the trouble diagnosis for DTC P0607. Refer to
EC-284
.
Priority Detected items (DTC)
1  U1000 U1001 CAN communication line  P0101 P0102 P0103 Mass air flow sensor
 P0112 P0113 P0127 Intake air temperature sensor
 P0116 P0117 P0118 P0125 Engine coolant temperature sensor
 P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
 P0128 Thermostat function
 P0181 P0182 P0183 Fuel tank temperature sensor
 P0327 P0328 P0332 P0333 Knock sensor
 P0335 Crankshaft position sensor (POS)
 P0340 Camshaft posi tion sensor (PHASE)
 P0460 P0461 P0462 P0463 Fuel level sensor
 P0500 Vehicle speed sensor
 P0605 P0607 ECM
 P0643 Sensor power supply
 P0700 TCM
 P0705 Transmission range switch
 P0850 Park/neutral position (PNP) switch
 P1550 P1551 P1552 P1553 P1554 Battery current sensor
 P1610 - P1615 NATS
 P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
Revision: December 20092009 QX56

EC-476
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-103,
EC-109
Engine coolant temperature sensor circuit
333
EC-120,
EC-128
Air fuel ratio (A/F ) sensor 1 circuit EC-136
,
EC-140
,
EC-143
,
EC-146
,
EC-377

Throttle position sensor circuit 22EC-124
,
EC-185
,
EC-302
,
EC-304
,
EC-369
Accelerator pedal position sensor circuit 3 2 1 EC-280
,
EC-362
,
EC-365
,
EC-373
Knock sensor circuit 2 3 EC-195
Crankshaft position sensor (POS) circuit 2 2EC-198
Camshaft position sensor (PHASE) circuit 3 2 EC-202
Vehicle speed signal circuit 2 3 3 3 EC-271
Power steering pressure sensor circuit 2 3 3 EC-277
ECM 22333333333 EC-280,
EC-282
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-100
Transmission range signal circuit 3 3 3 3 3 EC-288
Refrigerant pressure sensor circuit 2 3 3 4EC-416
Electrical load signal circuit 3EC-390
Air conditioner circuit 223333333 3 2HAC-25
ABS actuator and electric unit (control unit) 4 BRC-37
SYMPTOM
Refer-
ence 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: December 20092009 QX56

ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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
Fuel Fuel tank 5
5 FL-11
Fuel piping 5 5 5 5 5 5
FL-6
Va p o r l o c k —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gasoline,
Low octane) —
Air Air duct
55555 5 EM-25
Air cleaner
EM-25
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-25
Electric throttle control actuator
EM-26
Air leakage from intake manifold/
Collector/GasketEM-26
Cranking Battery
111111
11
PG-77
Generator circuit
CHG-6
Starter circuit 3STR-8
Signal plate 6EM-45
Transmission range signal 4TM-44
Engine Cylinder head
55555 55 5 EM-68
Cylinder head gasket 4 3
Cylinder block
66666 66 6 4
EM-83
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-45
Camshaft
EM-53
Intake valve timing controlEM-53
Intake valve
3EM-68
Exhaust valve
Revision: December 20092009 QX56

NORMAL OPERATING CONDITIONEC-479
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NORMAL OPERATING CONDITION
Fuel Cut Control (at No
Load and High Engine Speed)INFOID:0000000003771740
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-28, "System Description"
.
Sensor Input signal to ECM ECM function Actuator
TCM Neutral position
Fuel cut control Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed
Wheel sensor Vehicle speed*
Revision: December 20092009 QX56

EC-482
< PRECAUTION >[VK56DE]
PRECAUTIONS

Before replacing ECM, perform ECM Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-422, "ECM Terminal and Reference Value"
.
 Handle mass air flow sensor carefully to avoid damage.
 Do not disassemble mass air flow sensor.
 Do not clean mass air flow senso r with any type of detergent.
 Do not disassemble electric throttle control actuator.
 Even a slight leak in the ai r intake system can cause serious
incidents.
 Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
 After performing each TROUBLE DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displ ayed in the DTC Confirmation
Procedure if the repair is co mpleted. The Overall Function
Check should be a good result if the repair is completed.
 When measuring ECM signals with a circuit tester, never allow
the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
 Do not use ECM ground termina ls when measuring input/out-
put voltage. Doing so may result in damage to the ECM's tran-
sistor. Use a ground other than ECM terminals, such as the
ground.
 B1 indicates the bank 1, B2 indicates the bank 2 as shown in
the figure.
MEF040D
SEF217U
SEF348N
PBIB1144E
Revision: December 20092009 QX56

EC-496
< SERVICE DATA AND SPECIFICATIONS (SDS) [VK56DE]
SERVICE DATA AND SPECIFICATIONS (SDS)
Heated Oxygen sensor 2 Heater
INFOID:0000000003771762
Crankshaft Position Sensor (POS)INFOID:0000000003771763
Refer to EC-200, "Component Inspection".
Camshaft Position Sensor (PHASE)INFOID:0000000003771764
Refer to EC-204, "Component Inspection".
Throttle Control MotorINFOID:0000000003771765
Fuel InjectorINFOID:0000000003771766
Fuel PumpINFOID:0000000003771767
Resistance [at 25 °C (77 °F)] 8 - 10 Ω
Resistance [at 25°C (77 °F)] Approximately 1 - 15 Ω
Resistance [at 10 - 60°C (50 - 140 °F)] 11.1 - 14.5 Ω
Resistance [at 25°C (77 °F)] 0.2 - 5.0 Ω
Revision: December 20092009 QX56

EM-4
< PRECAUTION >
PRECAUTIONS
5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of a ll control units using CONSULT-III.
Precaution for Drain Engine CoolantINFOID:0000000005885850
Drain engine coolant when engine is cooled.
Precaution for Disconnecting Fuel PipingINFOID:0000000005885851
• Before starting work, make sure no fire or spark producing items are in the work area.
• Release fuel pressure before disconnecting and disassembly.
• After disconnecting pipes, plug openings to stop fuel leakage.
Precaution for Removal and DisassemblyINFOID:0000000005885852
• When instructed to use special service tools, use the s pecified tools. Always be careful to work safely, avoid
forceful or uninstructed operations.
• Exercise maximum care to avoid damage to mating or sliding surfaces.
• Cover openings of engine system with tape or the equivalent, if necessary, to seal out foreign materials.
• Mark and arrange disassembly parts in an organi zed way for easy troubleshooting and assembly.
• When loosening nuts and bolts, as a basic rule, start with the one furthest outside, then the one diagonally opposite, and so on. If the order of loosening is specified, do exactly as specified. Power tools may be used
where noted in the step.
Precaution for Inspection, Repair and ReplacementINFOID:0000000005885853
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precaution for Assembly and InstallationINFOID:0000000005885854
• Use torque wrench to tighten bolts or nuts to specification.
• When tightening nuts and bolts, as a basic rule, equally tighten in several different steps starting with theones in center, then ones on inside and outside diagonally in this order. If the order of tightening is specified,
do exactly as specified.
• Replace with new gasket, packing, oil seal or O-ring.
• Thoroughly wash, clean, and air-blow each part. Carefully check engine oil or engine coolant passages for any restriction and blockage.
• Avoid damaging sliding or mating surfaces. Completely remove foreign materials such as cloth lint or dust. Before assembly, oil sliding surfaces well.
• Release air within route when refilling after draining engine coolant.
• Before starting engine, apply fuel pressure to fuel lines with turning ignition switch ON (with engine stopped). Then make sure that there are no leaks at fuel line connections.
• After repairing, start engine and increase engine s peed to check engine coolant, fuel, oil, and exhaust sys-
tems for leakage.
Parts Requiring Angular TighteningINFOID:0000000005885855
• For final tightening of the following engine parts use Tool:
- Cylinder head bolts
- Main bearing cap bolts
- Connecting rod cap bolts
- Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angle tightening)
• Do not use a torque value for final tightening.
• The torque value for these parts are for a preliminary step.
• Ensure thread and seat surfaces are clean and lightly coated with engine oil. Tool number : KV10112100 (BT-8653-A)
Revision: December 20092009 QX56