2008 INFINITI QX56 engine

EC-14
< BASIC INSPECTION >[VK56DE]
INSPECTION AND ADJUSTMENT
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-III. Refer to EC-17, "
Idle Speed and Ignition
Timing Check" .
Without CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4.PERFORM ACCELERATOR PEDAL RE LEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5.PERFORM THROTTLE VALVE CL OSED POSITION LEARNING
Perform EC-18, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
6.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-18, "
Idle Air Volume Learning" .
Is Idle Air Volume Lear ning carried out successfully?
Ye s o r N o
Ye s > > G O T O 7 .
No >> 1. Follow the instruction of Idle Air Volume Learning. 2. GO TO 4.
7.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-III. Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-III
PBIA8513J
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTEC-15
< BASIC INSPECTION > [VK56DE]
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1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-211
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-207
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace. 2. GO TO 4.
9.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM f unction. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NAT S) system and registration of all IVIS (NATS) ignition key IDs. Refer to
SEC-13, "
System Diagram".
>> GO TO 4.
10.CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11 .PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-18, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-18, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning. 650
± 50 rpm (in P or N position)
15 ± 5 ° BTDC (in P or N position)
BBIA0379E
Revision: March 2010 2008 QX56

EC-16
< BASIC INSPECTION >[VK56DE]
INSPECTION AND ADJUSTMENT
2. GO TO 4.
14.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-III.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-45, "
Removal and Installation".
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation. 2. GO TO 4.
17.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-211
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-207
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace. 2. GO TO 4.
18.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but this is a rare case.)
2. Perform initialization of IVIS (NATS) system and regist ration of all IVIS (NATS) ignition key IDs. Refer to
SEC-13, "
System Diagram".
>> GO TO 4.
19.INSPECTION END 650
± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
15 ± 5 ° BTDC (in P or N position)
BBIA0379E
Revision: March 2010 2008 QX56

EC-18
< BASIC INSPECTION >[VK56DE]
INSPECTION AND ADJUSTMENT
With CONSULT-III
1. Check the VIN of the vehicle and note it. Refer to
GI-20, "Model Variation".
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION ” in “WORK SUPPORT” mode.
4. Follow the instruction of CONSULT-III display.
Accelerator Pedal Released Position LearningINFOID:0000000001351333
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal positi on sensor output signal. It must be performed each time
harness connector of accelerator pedal pos ition sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningINFOID:0000000001351334
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to l earn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal . It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF wait at least 10 seconds. Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningINFOID:0000000001351335
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
• Each time electric throttle control actuator or ECM is replaced.
• Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the follo wing conditions are missed for even a moment.
• Battery voltage: More than 12.9V (At idle)
• Engine coolant temperature: 70 - 100 °C (158 - 212° F)
• Selector lever: P or N
• Electric load switch: OFF (Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
start the headlamp will not be illuminated.
• Steering wheel: Neutral (Straight-ahead position)
• Vehicle speed: Stopped
• Transmission: Warmed-up
- With CONSULT-III: Drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T” system indi- cates less than 0.9V.
- Without CONSULT-III: Drive vehicle for 10 minutes.
OPERATION PROCEDURE
Revision: March 2010 2008 QX56

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
Revision: March 2010 2008 QX56

EC-20
< BASIC INSPECTION >[VK56DE]
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
< FUNCTION DIAGNOSIS > [VK56DE]
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FUNCTION DIAGNOSIS
ENGINE CONTROL SYSTEM
System DiagramINFOID:0000000001351344
PBIB3438E
Revision: March 2010
2008 QX56

EC-22
< FUNCTION DIAGNOSIS >[VK56DE]
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
Revision: March 2010 2008 QX56