2011 INFINITI QX56 Camshaft position sensor

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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
VK56VD
PRECAUTION ................ ...............................
9
PRECAUTIONS .............................................. .....9
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
9
Precaution for Procedure without Cowl Top Cover ......9
Precautions For Xenon Headlamp Service ...............9
On Board Diagnostic (OBD) System of Engine
and A/T ....................................................................
10
General Precautions ...............................................10
PREPARATION ...........................................14
PREPARATION .............................................. ....14
Special Service Tools .......................................... ....14
Commercial Service Tools ......................................14
SYSTEM DESCRIPTION .............................16
COMPONENT PARTS ................................... ....16
Component Parts Location .................................. ....16
Component Description ...........................................19
Accelerator Pedal Position Sensor ..........................21
Air Fuel Ratio (A/F) Sensor 1 ..................................21
ASCD Brake Switch & Stop Lamp Switch ...............21
ASCD Steering Switch ............................................21
ASCD Indicators ......................................................21
Battery Current Sensor (With Battery Tempera-
ture Sensor) ............................................................
22
Camshaft Position Sensor .......................................22
Crankshaft Position Sensor .....................................23
ECM ........................................................................23
Electric Throttle Control Actuator ............................23
Electrically-controlled cooling fan coupling .............24
Engine Coolant Temperature Sensor ......................25
Engine Oil Temperature Sensor ..............................25
EVAP Control System Pressure Sensor .................26
EVAP Canister Vent Control Valve .........................26
EVAP Canister Purge Volume Control Solenoid
Valve .................................................................... ....
26
Fuel Injector .............................................................26
Fuel Level Sensor ....................................................26
Fuel Pump Control Module ......................................27
Fuel Rail Pressure Sensor .......................................27
Fuel Tank Temperature Sensor ...............................27
Heated Oxygen Sensor 2 ........................................27
High Pressure Fuel Pump .......................................28
ICC Brake Switch & Stop Lamp Switch ...................29
ICC Steering Switch ................................................29
Ignition Coil With Power Transistor .........................29
Intake Valve Timing Control Solenoid Valve ...........29
Knock Sensor ...................................................... ....30
Low Fuel Pressure Sensor ......................................30
Low Pressure Fuel Pump ........................................30
Malfunction Indicator Lamp (MIL) ............................30
Manifold Absolute Pressure Sensor ........................31
Mass Air Flow Sensor (With Intake Air Tempera-
ture Sensor) .............................................................
31
Power Steering Pressure (PSP) Sensor ..................31
Refrigerant Pressure Sensor ............................... ....32
VVEL Actuator Motor ...............................................32
VVEL Actuator Motor Relay .....................................32
VVEL Control Module ..............................................32
VVEL Control Shaft Position Sensor .......................32
STRUCTURE AND OPERATION .....................33
Positive Crankcase Ventilation ................................33
On Board Refueling Vapor Recovery (ORVR) ........34
SYSTEM ............................................................35
ENGINE CONTROL SYSTEM ........................ ...........35
ENGINE CONTROL SYSTEM : System Diagram ....35
ENGINE CONTROL SYSTEM : System Descrip-
tion ...........................................................................
35
DIRECT INJECTION GASOLINE SYSTEM .......... ....36
DIRECT INJECTION GASOLINE SYSTEM :
System Diagram .....................................................
36
Revision: 2010 May2011 QX56

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P0300, P0301, P0302, P0303, P0304, P0305,
P0306, P0307, P0308 MISFIRE ..................... ..
291
DTC Logic ........................................................... ..291
Diagnosis Procedure .............................................292
P0327, P0328, P0332, P0333 KS ....................297
DTC Logic ........................................................... ..297
Diagnosis Procedure .............................................297
Component Inspection (Knock Sensor) ................298
P0335 CKP SENSOR .......................................299
DTC Logic ........................................................... ..299
Diagnosis Procedure .............................................299
Component Inspection (Crankshaft Position Sen-
sor) ........................................................................
301
P0340, P0345 CMP SENSOR ..........................303
DTC Logic ........................................................... ..303
Diagnosis Procedure .............................................304
Component Inspection (Camshaft Position Sen-
sor) ........................................................................
306
P0420, P0430 THREE WAY CATALYST
FUNCTION .......................................................
307
DTC Logic ........................................................... ..307
Component Function Check ..................................308
Diagnosis Procedure .............................................309
P0441 EVAP CONTROL SYSTEM ..................312
DTC Logic ........................................................... ..312
Component Function Check ..................................313
Diagnosis Procedure .............................................314
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE .......................
317
DTC Logic ........................................................... ..317
Diagnosis Procedure .............................................318
Component Inspection (EVAP Canister Purge
Volume Control Solenoid Valve) ...........................
320
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SOLENOID VALVE .......
322
DTC Logic ........................................................... ..322
Diagnosis Procedure .............................................322
Component Inspection (EVAP Canister Purge
Volume Control Solenoid Valve) ...........................
323
P0447 EVAP CANISTER VENT CONTROL
VALVE ..............................................................
325
DTC Logic ........................................................... ..325
Diagnosis Procedure .............................................325
Component Inspection (EVAP Canister Vent Con-
trol Valve) ............................................................ ..
327
P0448 EVAP CANISTER VENT CONTROL
VALVE ..............................................................
329
DTC Logic ........................................................... ..329
Diagnosis Procedure .............................................329
Component Inspection (EVAP Canister Vent Con-
trol Valve) ............................................................ ..
331
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
333
DTC Logic ............................................................ ..333
Diagnosis Procedure .............................................333
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
335
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
336
DTC Logic ..............................................................336
Diagnosis Procedure .............................................337
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
339
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
341
DTC Logic ..............................................................341
Diagnosis Procedure .............................................342
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
345
P0456 EVAP CONTROL SYSTEM .................346
DTC Logic ..............................................................346
Diagnosis Procedure .............................................347
Component Inspection (Fuel Filler Cap) ................350
P0460 FUEL LEVEL SENSOR .......................352
DTC Logic ............................................................ ..352
Diagnosis Procedure .............................................352
P0461 FUEL LEVEL SENSOR .......................353
DTC Logic ..............................................................353
Component Function Check ..................................353
Diagnosis Procedure .............................................354
P0462, P0463 FUEL LEVEL SENSOR ...........355
DTC Logic ..............................................................355
Diagnosis Procedure .............................................355
P0500 VSS ......................................................356
Description ........................................................... ..356
DTC Logic ..............................................................356
Component Function Check ..................................357
Diagnosis Procedure .............................................357
P0506 ISC SYSTEM ........................................358
Description .............................................................358
DTC Logic ..............................................................358
Diagnosis Procedure .............................................358
P0507 ISC SYSTEM ........................................360
Description .............................................................360
DTC Logic ..............................................................360
Diagnosis Procedure .............................................360
P050E COLD START CONTROL ...................362
Description .............................................................362
DTC Logic ..............................................................362
Diagnosis Procedure .............................................362
P0524 ENGINE OIL PRESSURE ....................364
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-17
< SYSTEM DESCRIPTION > [VK56VD]
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EXHAUST COMPARTMENT
1. VVEL actuator motor (bank 2) 2. Ignition coil (with power transistor)
and spark plug (bank 2)3. Camshaft position sensor (bank 2)
4. High pressure fuel pump 5. Intake valve timing control solenoid valve (bank 2)6. Electric-viscous fan assembly
7. Engine oil temperature sensor 8. Intake valve timing control solenoid valve (bank 1)9. Camshaft position sensor (bank 1)
10. Ignition coil (with power transistor) and spark plug (bank 1) 11. VVEL actuator motor (bank 1) 12. Low fuel pressure sensor
13. Positive crankcase ventilation (PCV) valve 14. Fuel injector (bank 2) 15. Knock sensor (bank 2)
16. Knock sensor (bank 1) 17. Fuel injector (bank 1) 18. Fuel rail pressure sensor
19. Manifold absolute pressure sensor 20. VVEL control shaft position sensor (bank 1)21. Crankshaft position sensor
22. Engine coolant temperature sensor 23. VVEL control shaft position sensor (bank 2)
A. Top view of the engine (View with intake manifold is re-
moved) B. Rear view of the engine
:Engine front
JPBIA3972ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-19
< SYSTEM DESCRIPTION > [VK56VD]
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Component DescriptionINFOID:0000000006217657
1. ASCD steering switch
ICC steering switch 2. Snow mode switch 3. Fuel level sensor unit and fuel pump
assembly (with fuel tank temperature
sensor)
4. Fuel pump control module (FPCM) 5. EVAP canister vent control valve 6. EVAP canister
7. EVAP control system pressure sen- sor 8. Stop lamp switch 9. ASCD brake switch
ICC brake switch
10. Accelerator pedal position sensor
JSBIA0606ZZ
Component Reference
ECM EC-23, "
ECM"
Malfunction indicator lamp (MIL)EC-30, "Malfunction Indicator Lamp (MIL)"
Ignition coil with power transistorEC-29, "Ignition Coil With Power Transistor"
Accelerator pedal position sensorEC-21, "Accelerator Pedal Position Sensor"
Mass air flow sensor
EC-31, "Mass Air Flow Sensor (With Intake Air Temperature Sen-
sor)"Intake air temperature sensor
Electric throttle control actuator
EC-23, "
Electric Throttle Control Actuator"Throttle control motor relay
Throttle control motor
Throttle position sensor
Crankshaft position sensorEC-23, "
Crankshaft Position Sensor"
Camshaft position sensorEC-22, "Camshaft Position Sensor"
Engine coolant temperature sensorEC-25, "Engine Coolant Temperature Sensor"
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EC-22
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
Battery Current Sensor (With Battery Temperature Sensor)
INFOID:0000000006217663
OUTLINE
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator.
Based on sensor signals, ECM judges whether or not the power
generation voltage variable control is performed. When performing
the power generation voltage variable control, ECM calculates the
target power generation voltage based on the sensor signal. And
ECM sends the calculated value as the power generation command
value to IPDM E/R. For the details of the power generation voltage
variable control, refer to CHG-7, "
POWER GENERATION VOLTAGE
VARIABLE CONTROL SYSTEM : System Description".
CAUTION:
Never connect the electrical component or the groun d wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
BATTERY CURRENT SENSOR
The battery current sensor is installed to the battery cable at the negative terminal. The sensor measures the
charging/discharging current of the battery.
BATTERY TEMPERATURE SENSOR
Battery temperature sensor is int egrated in battery current sensor.
The sensor measures ambient temperature around the battery.
The electrical resistance of the t hermistor decreases as temperature
increases.

*: These data are reference values and are measured between ECM terminals.
Camshaft Position SensorINFOID:0000000006217664
The camshaft position (CMP) sensor senses the protrusion of the
signal plate installed to the camshaft (INT) front end to identify a par-
ticular cylinder. The camshaft position sensor senses the piston posi-
tion.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
When the crankshaft position sens or system becomes inoperative,
the camshaft position sensor provides various controls of engine parts instead, utilizing timing of cylinder iden-
tification signals.
JPBIA3262ZZ
Temperature [ °C ( °F)] Voltage* (V) Resistance (k Ω)
25 (77) 3.333 1.9 - 2.1
90 (194) 0.969 0.222 - 0.258
SEF012P
JMBIA0064ZZ
Revision: 2010 May2011 QX56

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*1: This sensor is not used to control the engine system under normal conditions.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The adoption of the direct fuel injection method enables
more accurate adjustment of fuel injection quantity by
injecting atomized high-pressure fuel directly into the cylinder. This method allows high-powered engine, low
fuel consumption, and emissions-reduction.
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air and fuel rail pressure) from the crankshaft position sensor,
camshaft position sensor, mass air flow sensor and the fuel rail pressure sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated to improve engine performance under various operat-
ing conditions as listed below.
 During warm-up
 When starting the engine
 During acceleration
 Hot-engine operation
 When selector lever position is changed from N to D
 High-load, high-speed operation

 During deceleration
 During high engine speed operation
FUEL INJECTION CONTROL
Stratified-charge Combustion
Stratified-charge combustion is a combustion method wh ich enables extremely lean combustion by injecting
fuel in the latter half of a compression process, coll ecting combustible air-fuel around the spark plug, and form-
ing fuel-free airspace around the mixture.
Right after a start with the engine cold, the catalyst warm-up is accelerated by stratified-charge combustion.
Homogeneous Combustion
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
2
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor Camshaft position
Mass air flow sensor Amount of intake air
Intake air temperature sensor Intake air temperature
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Fuel rail pressure sensor Fuel rail pressure
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
TCM Gear position
Battery
Battery voltage*
2
Knock sensor Engine knocking condition
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit) VDC/TCS operation command
A/C auto amp. A/C ON signal
Combination meter Vehicle speed
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SYSTEMEC-39
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Fuel is injected into each cylinder during each engine cycle accord-
ing to the ignition order.
STRATIFIED-CHARGE START CONTROL
The use of the stratified-charge combustion met
hod enables emissions-reduction when starting the engine
with engine coolant temperature between 5 °C (41 °F) and 40 °C (104 °F).
FUEL SHUT-OFF
Fuel to each cylinder is shut-off during deceleration, operation of the engine at excessively high speed or oper-
ation of the vehicle at excessively high speed.
FUEL PRESSURE CONTROL
FUEL PRESSURE CONTROL : System DiagramINFOID:0000000006217701
FUEL PRESSURE CONTROL : System DescriptionINFOID:0000000006217702
INPUT/OUTPUT SIGNAL CHART
JSBIA0407GB
JSBIA0315GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed
Fuel injection
& mixture ratio
controlHigh pressure fuel pump
Camshaft position sensor Camshaft position
Fuel rail pressure sensor Fuel rail pressure
Low fuel pressure sensor Low fuel pressure
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage
Revision: 2010 May2011 QX56

SYSTEMEC-41
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COOLING FAN CONTROL : System DiagramINFOID:0000000006217703
COOLING FAN CONTROL : System DescriptionINFOID:0000000006217704
INPUT/OUTPUT SIGNAL CHART
*1: The ECM determines the engine speed by the signals of crankshaft position and camshaft position.
*2: This signal is sent to ECM via the CAN communication line.
SYSTEM DESCRIPTION
 Based on a signal transmitted from each sensor, ECM calc
ulates a target fan speed responsive to a driving
condition. In addition, ECM calculates a fan pulley speed according to an engine speed and transmits a cool-
ing fan request signal to IPDM E/R via the CAN comm unication line to satisfy the target fan speed. Then,
IPDM E/R transmits ON/OFF pulse duty signal to electrically-controlled cooling fan coupling.
The cooling fan speed sensor detects a cooling f an speed and transmits the detection result to ECM.
 ECM judges the start signal state from the engine speed signal and battery voltage.
ELECTRIC IGNITION SYSTEM
JSBIA0237GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
1
Cooling fan speed request
signal*2
IPDM E/R
↓
Electrically-controlled cooling fan
coupling
Camshaft position sensor Camshaft position
Engine coolant temperature sensor Engine coolant temperature
Refrigerant pressure sensor Refrigerant pressure
Intake air temperature sensor Intake air temperature
Battery Battery voltage
Combination meter
Vehicle speed signal*
2
BCMA/C switch signal*2
Cooling fan speed sensor Cooling fan speed
Revision: 2010 May2011 QX56