sensor INFINITI QX56 2011 Factory Service Manual

SYSTEMEC-39
< SYSTEM DESCRIPTION > [VK56VD]
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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
< SYSTEM DESCRIPTION > [VK56VD]
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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

EC-42
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
ELECTRIC IGNITION SYSTEM : System Diagram
INFOID:0000000006217705
ELECTRIC IGNITION SYSTEM : System DescriptionINFOID:0000000006217706
INPUT/OUTPUT SIGNAL CHART
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
Ignition order: 1 - 8 - 7 - 3 - 6 - 5 - 4 - 2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised by the ECM according to the other data stored in
the ECM.
 At starting
 During warm-up
 At idle
 At low battery voltage
 During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
JPBIA3271GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
1
Piston position
Ignition timing
controlIgnition coil
(with power transistor)
Camshaft position sensor
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
TCM Gear position
Battery
Battery voltage*
1
Knock sensor Engine knocking condition
Combination meterVehicle speed*
2
Revision: 2010 May2011 QX56

SYSTEMEC-43
< SYSTEM DESCRIPTION > [VK56VD]
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INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL : System DiagramINFOID:0000000006217707
INTAKE VALVE TIMING CONT
ROL : System DescriptionINFOID:0000000006217708
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
This mechanism hydraulically controls cam phases c ontinuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft posit ion, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing control solenoid
valve depending on driving status. This makes it possible to control the shut/open timing of the intake valve to
increase engine torque in low/mid speed range and output in high speed range.
VVEL SYSTEM
JMBIA2174GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed and piston position
Intake valve timing
controlIntake valve timing control
solenoid valve
Camshaft position sensor
Engine oil temperature sensor Engine oil temperature
Engine coolant temperature sensor Engine coolant temperature
Combination meter Vehicle speed*
PBIB3276E
Revision: 2010 May2011 QX56

EC-44
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
VVEL SYSTEM : System Diagram
INFOID:0000000006217709
VVEL SYSTEM : System DescriptionINFOID:0000000006217710
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
JSBIA0539GB
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor
Crankshaft position sensor Engine speed and piston position
VVEL controlVVEL control module
↓
VVEL actuator motor assem-
bly
Accelerator pedal position sensor Accelerator pedal position
VVEL control shaft
position sensor
↓
VVEL control module Control shaft actual angle
1. VVEL control shaft position
sensor 2. Drive shaft 3. Link A
4. Eccentric cam 5. Output cam 6. Valve lifter
7. Intake valve 8. Intake camshaft sprocket 9. Control shaft
10. Ball screw shaft 11. Ball screw nu t 12. VVEL actuator motor assembly
13. Rocker arm 14. Link B
JSBIA0463ZZ
Revision: 2010 May2011 QX56

EC-46
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydr
ocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplis hed by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into t he EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not oper ating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume contro l solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
AIR CONDITIONING CUT CONTROL
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor  Engine speed*
1
 Piston position
EVAP canister
purge flow controlEVAP canister purge volume
control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio
feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
EVAP control system pressure sensor Pressure in purge line
Combination meter Vehicle speed*
2
PBIB1631E
Revision: 2010 May2011 QX56

SYSTEMEC-47
< SYSTEM DESCRIPTION > [VK56VD]
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AIR CONDITIONING CUT CONTROL : System DiagramINFOID:0000000006217713
AIR CONDITIONING CUT CONTROL : System DescriptionINFOID:0000000006217714
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM via the CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
 When the accelerator pedal is fully depressed.
 When cranking the engine.
 At high engine speeds.
 When the engine coolant temperature becomes excessively high.
 When operating power steering during low engine speed or low vehicle speed.
 When engine speed is excessively low.
 When refrigerant pressure is excessively low or high.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
JMBIA1457GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor Engine speed*
2
Air conditioner cut
controlIPDM E/R
↓
A/C relay
↓
Compressor
Engine coolant temperature sensor Engine coolant temperature
Accelerator pedal position sensor Accelerator pedal position
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
A/C auto amp.A/C ON signal*
1
A/C evaporator temperature*1
Target A/C evaporator temperature*1
Blower fan ON signal
Combination meter Vehicle speed*
1
Revision: 2010 May2011 QX56

EC-48
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
AUTOMATIC SPEED CONTROL DEVI CE (ASCD) : System Diagram
INFOID:0000000006217715
AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System DescriptionINFOID:0000000006217716
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM via the CAN communication line
BASIC ASCD SYSTEM
 Automatic Speed Control Device (ASCD) allows a dr iver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can be set the vehicle speed in the set speed range.
 ECM controls throttle angle of electric th rottle control actuator to regulate engine speed.
 Operation status of ASCD is indicated in combination meter.
 If any malfunction occurs in the ASCD system, it automatically deactivates the ASCD control.
Refer to EC-49, "
AUTMATIC SPEED CONTROL DEVICE (A SCD) : Switch Name and Function" for ASCD
operating instructions.
CAUTION:
Always drive vehicle in a safe manner according to traffic conditions and obey all traffic laws.
CAN COMMUNICATION
CAN COMMUNICATION : System DescriptionINFOID:0000000006217718
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication s peed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CA N communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
Refer to LAN-28, "
CAN COMMUNICATION SYSTEM : CAN Communication Signal Chart", about CAN com-
munication for detail.
JPBIA3272GB
Sensor Input signal to ECM ECM function Actuator
ASCD steering switch ASCD steering switch operation
ASCD vehicle speed control Electric throttle control ac-
tuator
 Combination meter
ASCD brake switch
Brake pedal operation
Sto p l am p s w it ch
TCM Park/neutral position signal
Output shaft revolution signal*
Combination meter Vehicle speed signal*
Revision: 2010 May2011 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-51
< SYSTEM DESCRIPTION > [VK56VD]
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Diagnosis DescriptionINFOID:0000000006217720
This system is an on board diagnostic system that re
cords exhaust emission-related diagnostic information
and detects a sensors/actuator-related malfunction. A ma lfunction is indicated by the malfunction indicator
lamp (MIL) and stored in ECU memory as a DTC. The diagnostic information can be obtained with the diag-
nostic tool (GST: Generic Scan Tool).
GST (Generic Scan Tool)INFOID:0000000006217721
When GST is connected with a data link connector equipped on the vehicle side, it will communicate with the
control unit equipped in the vehicle and then enable va rious kinds of diagnostic tests. Refer to GI-48, "
Descrip-
tion".
NOTE:
Service $0A is not applied for r egions where it is not mandated.
Revision: 2010 May2011 QX56

EC-60
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION : Malf unction Indicator Lamp (MIL)
INFOID:0000000006217727
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
If the MIL does not light up, refer to EC-515, "
Component Func-
tion Check".
2. When the engine is started, the MIL should go off. If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
On Board Diagn osis FunctionINFOID:0000000006217728
ON BOARD DIAGNOSIS ITEM
The on board diagnostic system has the following functions.
BLUB CHECK MODE
Description
This function allows damage inspection in the MIL bulb (blown, open circuit, etc.).
Operation Procedure
1. Turn ignition switch ON.
2. The MIL on the instrument panel should stay ON.
If it remains OFF, check MIL circuit. Refer to EC-515, "
Diagnosis Procedure".
SRT STATUS MODE
Description
This function allows to read if ECM has completed t he self-diagnoses of major emission control systems and
components. For SRT, refer to EC-58, "
DIAGNOSIS DESCRIPTION : Syst em Readiness Test (SRT) Code".
Operation Procedure
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown blow.
 ECM continues to illuminate MIL if all SRT codes are set.
SEF217U
Diagnostic test mode Function
Bulb check MIL can be checked.
SRT status ECM can read if SRT codes are set.
Malfunction warning If ECM detects a malfunction, it illuminates or blinks MIL to inform the driver that a malfunction has been detected.
Self-diagnostic results DTCs or 1st trip DTCs stored in ECM can be read.
Accelerator pedal released po-
sition learning ECM can learn the accelerator pedal released position. Refer to
EC-146, "
Description".
Throttle valve closed position
learning ECM can learn the throttle valve closed position. Refer to
EC-147, "
Description".
Idle air volume learning ECM can learn the idle air volume. Refer to EC-148, "
Description".
VVEL control sh aft position
sensor adjustment The initial position of the VVEL control shaft position sensor can be adjusted. Refer to
EC-150, "
De-
scription".
Revision: 2010 May2011 QX56