engine INFINITI QX56 2008 Factory Service Manual

INSPECTION AND ADJUSTMENTEC-19
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With CONSULT-III
1. Perform
EC-18, "Accelerator Pedal Released Position Learning" .
2. Perform EC-18, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREP ARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEA RN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-III screen. If “CMPLT” is not displayed, Idle Air Vol-
ume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to
the DIAGNOSTIC PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
Without CONSULT-III
NOTE:
•It is better to count the time accurately with a clock.
• It is impossible to switch the di agnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform EC-18, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-18, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREP ARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quick ly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
SEC897C
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EC-20
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INSPECTION AND ADJUSTMENT
13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1. Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttl e valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-75
.
5. If any of the following conditions occur after the engine has st arted, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:
• Engine stalls.
• Erroneous idle.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
Revision: March 2010 2008 QX56

ENGINE CONTROL SYSTEMEC-21
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FUNCTION DIAGNOSIS
ENGINE CONTROL SYSTEM
System DiagramINFOID:0000000001351344
PBIB3438E
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EC-22
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ENGINE CONTROL SYSTEM
Engine Control Comp onent Parts Location
INFOID:0000000001351343
1. ECM 2. Battery current sensor 3. Power steering pressure sensor
4. Ignition coil (with power transistor) and spark plug (bank 2) 5. Refrigerant pressure sensor 6. Intake valve timing control position
sensor (bank 2)
7. Intake valve timing control solenoid valve (bank 2) 8. Engine coolant temperature sensor 9. Electric throttle control actuator
10. Intake valve timing control position sensor (bank 1) 11. Intake valve timing control solenoid
valve (bank 1) 12. Cooling fan motor
13. Camshaft position sensor (PHASE) 14. I gnition coil (with power transistor)
and spark plug (bank 1) 15. Mass air flow sensor (with intake air
temperature sensor)
16. A/F sensor 1 (bank 1) 17. EVAP service port 18. Fuel injector (bank 1)
19. Knock sensor (bank 1) 20. EVAP canister purge volume control
solenoid valve 21. Knock sensor (bank 2)
22. Fuel injector (bank 2) 23. A/F sensor 1 (bank 2) 24. IPDM E/R
BBIA0743E
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ENGINE CONTROL SYSTEMEC-23
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1. Body ground (view with battery re-
moved) 2. Body ground (view with battery re-
moved) 3. Body ground
4. No. 1 ignition coil 5. Engine ground6. Mass air flow sensor (with intake air
temperature sensor)
7. IPDM E/R 8. Battery9. Radiator hose
BBIA0778E
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EC-24
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ENGINE CONTROL SYSTEM
10. Camshaft position sensor (PHASE) 11
. Electric throttle control actuator
(view with intake air duct removed) 12. Cooling fan motor harness connec-
tor
: Vehicle front
BBIA0739E
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ENGINE CONTROL SYSTEMEC-25
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1. EVAP canister purge volume control
solenoid valve (view with engine
cover removed) 2. EVAP service port (view with engine
cover removed) 3. Crankshaft position sensor (POS)
(view from under the vehicle)
4. Engine oil pan (view from under the vehicle) 5. Condenser-1
6. Brake fluid reservoir
7. EVAP canister (view with fuel tank removed) 8. EVAP control system pressure sen-
sor (view with fuel tank removed) 9. EVAP canister vent control valve
(view with fuel tank removed)
10. Rear suspension member (view with fuel tank removed) 11. Refrigerant pressure sensor (view
with front grille removed) 12. Intake valve timing control position
sensor (bank 2) (view with engine
cover and intake air duct removed)
13. Intake valve timing control position sensor (bank 1) (view with engine
cover and intake air duct removed) 14. Intake valve timing control solenoid
valve (bank 2) (view with engine cov-
er and intake air duct removed) 15. Drive belt (view with engine cover
and intake air duct removed)
16. Radiator hose (view with engine cov- er and intake air duct removed) 17. Intake valve timing control solenoid
valve (bank 1) (view with engine cov-
er and intake air duct removed)
: Vehicle front
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EC-26
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ENGINE CONTROL SYSTEM
1. Knock sensor (bank 1) (view with en-
gine removed) 2. Knock sensor (bank 2) (view with en-
gine removed) 3. Battery current sensor
4. Power steering pressure sensor 5. Power steering fluid reservoir 6. Intake manifold
7. Engine coolant temperature sensor 8. Ignition coils (with power transistor) 9. Ignition coil (with power transistor)
10. Injector harness connectors (bank 2) 11. Injector harness connectors (bank 1) : Vehicle front
BBIA0384E
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ENGINE CONTROL SYSTEMEC-27
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PBIB2639E
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EC-28
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MULTIPORT FUEL INJECTION SYSTEM
MULTIPORT FUEL INJECTION SYSTEM
System DescriptionINFOID:0000000001351227
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
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 engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated 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 is changed from N to D
• High-load, high-speed operation

• During deceleration
• During high engine speed operation
Sensor Input signal to ECMECM functionActuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor
Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
TCM Gear position
Knock sensor Engine knocking condition
Battery Battery voltage*
3
Power steering pressure sensorPower steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit) VDC/TCS operation command*
2
Air conditioner switchAir conditioner operation*2
Wheel sensorVehicle speed*2
Revision: March 2010 2008 QX56