2009 INFINITI QX56 hood open

P0455 EVAP CONTROL SYSTEMEC-251
< COMPONENT DIAGNOSIS > [VK56DE]
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Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid valve
properly.
 If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
 Perform “DTC WORK SUPPORT” when the fuel level is between 1/4 and 3/4 full, and vehicle is placed
on flat level surface.
 Open engine hood before conducting the following procedures.
WITH CONSULT-III
1. Tighten fuel filler cap securely until ratcheting sound is heard.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
5. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70 °C (32 - 158 °F)
INT/A TEMP SE: 0 - 60 °C (32 - 140 °F)
6. Select “EVP SML LEAK P0442/P1442” of “EVAPO RATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-III.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-III screen, go to
EC-13, "Basic Inspection"
.
7. Make sure that “OK” is displayed. If “NG” is displayed, select “SELF-DIAG R ESULTS” mode and make sure that “EVAP GROSS LEAK
[P0455]” is displayed. If it is displayed, refer to EC-251, "Diagnosis Procedure"
.
If P0442 is displayed, perform Diagnostic Procedure for DTC P0442, EC-216, "Diagnosis Procedure"
.
WITH GST
NOTE:
Be sure to read the explanation of EC-456, "DTC Index"
before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-456, "DTC Index"
.
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select Service $07 with GST.  If P0441 is displayed on the screen, go to EC-211, "Diagnosis Procedure"
.
 If P0442 is displayed on the screen, go to EC-216, "Diagnosis Procedure"
.
 If P0455 is displayed on the screen, go to EC-251, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771522
1.CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
Revision: December 20092009 QX56

EC-258
< COMPONENT DIAGNOSIS >[VK56DE]
P0456 EVAP CONTROL SYSTEM
DTC Confirmation Procedure
INFOID:0000000003771525
NOTE:
 If DTC P0456 is displayed with P0442, firs t perform trouble diagnosis for DTC P0456.
 After repair, make sure that the hoses and clips are installed properly.
 If DTC Confirmation Procedure has been previously conducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
 Open engine hood before conducting following procedure.
 If any of following conditions are met just befo re the DTC confirmation procedure, leave the vehicle
for more than 1 hour.
- Fuel filler cap is removed.
- Fuel is refilled or drained.
- EVAP component parts is/are removed.
 Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Make sure the following conditions are met.
FUEL LEVEL SE: 0.25 - 1.4V
COOLAN TEMP/S: 0 - 32 °C (32 - 90 °F)
FUEL T/TMP SE: 0 - 35 °C (32 - 95 °F)
INT/A TEMP SE: More than 0 °C (32 °F)
If NG, turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle) or refilling/draining
fuel until the output voltage condition of the “FUE L LEVEL SE” meets within the range above and leave
the vehicle for more than 1 hour. Then start from step 1).
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Select “EVP V/S LEAK P0456/P1456” of “EVAPO RATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-III.
Follow the instruction displayed.
5. Make sure that “OK” is displayed. If “NG” is displayed, refer to EC-259, "Diagnosis Procedure"
.
NOTE:
 If the engine speed cannot be maintained with in the range displayed on CONSULT-III screen, go
to EC-13, "Basic Inspection"
.
 Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid
valve properly.
Overall Function CheckINFOID:0000000003771526
WITH GST
Use this procedure to check the overall function of the EV AP very small leak function. During this check, a 1st
trip DTC might not be confirmed.
CAUTION:
 Do not use compressed air, doing so may damage the EVAP system.
 Do not start engine.
 Do not exceeded 4.12 kPa (0.042 kg/cm
2 , 0.6 psi).
Revision: December 20092009 QX56

P0506 ISC SYSTEMEC-273
< COMPONENT DIAGNOSIS > [VK56DE]
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P0506 ISC SYSTEM
DescriptionINFOID:0000000003771546
NOTE:
If DTC P0506 is displayed with ot
her DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified leve l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicINFOID:0000000003771547
DTC Confirmation ProcedureINFOID:0000000003771548
NOTE:
 If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
 If the target idle speed is ou t of the specified value, perform EC-18, "Idle Air Volume Learning"
,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-495, "Idle
Speed and Ignition Timing".
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
 Always perform the test at a temperature above −10 °C (14 °F).
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-273, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771549
1.CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2.REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and regist ration of all IVIS(NATS) ignition key IDs. Refer to
SEC-6, "ECM RE-COMMUNICATING FUNCT ION : Special Repair Requirement"
.
4. Perform EC-17, "VIN Registration"
.
5. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506 Idle speed control system
RPM lower than expected The idle speed is less than the target idle speed
by 100 rpm or more.  Electric throttle control actuator
 Intake air leak
Revision: December 20092009 QX56

P0507 ISC SYSTEMEC-275
< COMPONENT DIAGNOSIS > [VK56DE]
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P0507 ISC SYSTEM
DescriptionINFOID:0000000003771550
NOTE:
If DTC P0507 is displayed with ot
her DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified leve l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicINFOID:0000000003771551
DTC Confirmation ProcedureINFOID:0000000003771552
NOTE:
 If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
 If the target idle speed is ou t of the specified value, perform EC-18, "Idle Air Volume Learning"
,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-495, "Idle
Speed and Ignition Timing".
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
 Always perform the test at a temperature above −10 °C (14 °F).
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-275, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771553
1.CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Discover air leak location and repair.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507 Idle speed control system
RPM higher than expected The idle speed is more than the target idle
speed by 200 rpm or more.  Electric throttle control actuator
 Intake air leak
 PCV system
Revision: December 20092009 QX56

ENGINE ASSEMBLYEM-79
< REMOVAL AND INSTALLATION >
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1. Release the fuel pressure. Refer to
EC-487, "Fuel Pressure Check".
2. Drain the engine coolant. Refer to CO-11, "
Changing Engine Coolant".
3. Drain the engine oil. Refer to LU-9, "
Changing Engine Oil".
4. Disconnect the battery negative and positive terminal. Refer to PG-76, "
Removal and Installation".
5. Remove the engine hood. Refer to DLK-230, "
Removal and Installation of Hood Assembly".
6. Remove the cowl extension. Refer to EXT-18, "
Removal and Installation".
7. Remove the air duct and air cleaner case assembly. Refer to EM-25, "
Removal and Installation".
8. Remove the radiator assembly and hoses. Refer to CO-15, "
Removal and Installation".
NOTE:
To prevent possible A/T fluid drain from transmissi on opening, use appropriate cap to close off transmis-
sion opening during operation.
9. Remove the drive belt. Refer to EM-13, "
Removal and Installation".
10. Remove the fan blade. Refer to CO-18, "
Removal and Installation (Crankshaft Driven Type)".
11. Disconnect the engine room harness from the fuse box and set it aside.
12. Disconnect the ECM.
13. Disconnect the engine room harness from the engine side and set it aside.
14. Disconnect the engine harness grounds.
15. Disconnect the power steering reservoir t ank from the engine and move it aside.
16. Disconnect the power steering oil pump from the engine. Move it aside and secure it using suitable wire or rope. Refer to ST-26, "
Removal and Installation"
17. Remove the A/C compressor bolts and set the compressor aside. Refer to HA-31, "Removal and Installa-
tion for Compressor" (ATC).
18. Disconnect the brake booster vacuum hose.
19. Disconnect the EVAP line.
20. Disconnect the fuel hose at the engine side connection. Refer to EM-40, "
Removal and Installation".
21. Disconnect the heater hoses at the cowl, and in stall plugs to avoid leakage of engine coolant.
22. Remove the A/T oil level indicator and indicator tube upper bolts.
23. Remove the front final drive assembly (4WD only). Refer to DLN-215, "
Removal and Installation".
24. Remove the exhaust manifolds. Refer to EM-30, "
Removal and Installation".
25. Install the engine slingers into the left bank cylinder head and right bank cylinder head.
26. Disconnect and remove the crankshaft position sensor (POS). Refer to EM-82, "
Exploded View".
27. Remove the A/T. Refer to TM-214, "
Removal and Installation
(2WD)" or TM-216, "Removal and Installation (4WD)".
NOTE:
To prevent possible A/T fluid drain from transmission opening,
use appropriate cap to close off transmission opening during
operation.
28. Lift using a hoist and secure the engine in position.
29. Remove the engine assembly from the vehicl e, avoid interference with the vehicle body.
CAUTION:
• Before and during lifting, always check if any harnesses are left connected.
30. Remove the parts that may restrict installation of the engine to the engine stand. NOTE:
This procedure is described assuming that you use an engine stand mounting to the surface to which the
transmission mounts. Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
WBIA0715E
Revision: December 20092009 QX56

DIAGNOSIS SYSTEM (IPDM E/R)EXL-25
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DIAGNOSIS SYSTEM (IPDM E/R)
Diagnosis DescriptionINFOID:0000000004215511
AUTO ACTIVE TEST
Description
In auto active test mode, the IPDM E/R sends a drive signal to the following systems to check their operation.
• Oil pressure low/coolant pressure high warning indicator
• Oil pressure gauge
• Rear window defogger
• Front wipers
• Tail, license and parking lamps
• Front fog lamps
• Headlamps (Hi, Lo)
• A/C compressor (magnetic clutch)
• Cooling fan
Operation Procedure
1. Close the hood and front door RH, and lift the wiper arms from the windshield (to prevent windshield dam-
age due to wiper operation).
NOTE:
When auto active test is performed with hood opened, sprinkle water on windshield before hand.
2. Turn ignition switch OFF.
3. Turn the ignition switch ON and, within 20 seconds, press the front door switch LH 10 times. Then turn the ignition switch OFF.
4. Turn the ignition switch ON within 10 seconds. Af ter that the horn sounds once and the auto active test
starts.
5. After a series of the following operations is repeated 3 times, auto active test is completed.
NOTE:
When auto active test mode has to be cancelled halfway through test, turn ignition switch OFF.
CAUTION:
• If auto active test mode cannot be actua ted, check door switch system. Refer to DLK-71, "
Descrip-
tion".
• Do not start the engine.
Inspection in Auto Active Test Mode
When auto active test mode is actuated, the following 7 steps are repeated 3 times.
Operation
sequence Inspection Location
Operation
1 Rear window defogger 10 seconds
2 Front wipers LO for 5 seconds → HI for 5 seconds
WKIA4655E
Revision: December 20092009 QX56

EXL-28
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (IPDM E/R)
ACTIVE TEST
Te s t i t e m
Monitor Item[Unit] MAIN SIG-
NALS Description
MOTOR FAN REQ
[1/2/3/4] ×Displays the status of the cooling fan speed request signal received from ECM via
CAN communication.
A/C COMP REQ
[OFF/ON] ×Displays the status of the A/C request signal received from AV control unit via
CAN communication.
TA I L & C L R R E Q
[OFF/ON] ×
Displays the status of the position light request signal received from BCM via CAN
communication.
HL LO REQ
[OFF/ON] ×Displays the status of the low beam request signal received from BCM via CAN
communication.
HL HI REQ
[OFF/ON] ×Displays the status of the high beam request signal received from BCM via CAN
communication.
FR FOG REQ
[OFF/ON] ×
Displays the status of the front fog lamp request signal received from BCM via
CAN communication.
HL WASHER REQ
[OFF/ON] NOTE:
This item is displayed, but cannot be monitored.
FR WIP REQ
[STOP/1LOW/LOW/HI] ×Displays the status of the front wiper request signal received from BCM via CAN
communication.
WIP AUTO STOP
[STOP P/ACT P] ×
Displays the status of the front wiper auto stop signal judged by IPDM E/R.
WIP PROT
[OFF/Block] ×
Displays the status of the front wiper fail-safe operation judged by IPDM E/R.
ST RLY REQ
[OFF/ON] Displays the status of the starter request signal received from ECM via CAN com-
munication.
IGN RLY
[OFF/ON] ×
Displays the status of the ignition relay judged by IPDM E/R.
RR DEF REQ
[OFF/ON] ×Displays the status of the rear defogger request signal received from AV control
unit via CAN communication.
OIL P SW
[OPEN/CLOSE] Displays the status of the oil pressure switch judged by IPDM E/R.
DTRL REQ
[OFF] Displays the status of the daytime light request signal received from BCM via CAN
communication.
HOOD SW
[OPEN/CLOSE] Displays the status of the hood switch judged by IPDM E/R.
THFT HRN REQ
[OFF/ON] Displays the status of the theft warning horn request signal received from BCM
via CAN communication.
HORN CHIRP
[OFF/ON] Displays the status of the horn reminder signal received from BCM via CAN com-
munication.
Test item
Operation Description
REAR DEFOGGER OFF
OFF
ON Operates rear window defogger relay.
FRONT WIPER OFF
OFF
LO Operates the front wiper relay.
HI Operates the front wiper relay and front wiper high relay.
MOTOR FAN 1O
FF
2O FF
3 Operates the cooling fan relay.
4 Operates the cooling fan relay.
Revision: December 20092009 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
EXL-121
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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE
ROOM)
Reference ValueINFOID:0000000004215514
VALUES ON THE DIAGNOSIS TOOL
Monitor Item ConditionValue/Status
MOTOR FAN REQ Engine idle speed Changes depending on engine
coolant temperature, air conditioner
operation status, vehicle speed,
etc.0 - 100 %
A/C COMP REQ A/C switch OFF
OFF
A/C switch ON ON
TA I L & C L R R E Q Lighting switch OFF
OFF
Lighting switch 1ST, 2ND, HI or AUTO (Light is illuminated) ON
HL LO REQ Lighting switch OFF
OFF
Lighting switch 2ND HI or AUTO (Light is illuminated) ON
HL HI REQ Lighting switch OFF
OFF
Lighting switch HI ON
FR FOG REQ Lighting switch 2ND or AUTO (Light
is illuminated) Front fog lamp switch OFF OFF
• Front fog lamp switch ON
• Daytime light activated (Canada
only) ON
HL WASHER REQ NOTE:
This item is displayed, but cannot be monitored.
OFF
FR WIP REQ Ignition switch ON Front wiper switch OFF
STOP
Front wiper switch INT 1LOW
Front wiper switch LO LOW
Front wiper switch HI HI
WIP AUTO STOP Ignition switch ON Front wiper stop position
STOP P
Any position other than front wiper
stop position ACT P
WIP PROT Ignition switch ON Front wiper operates normally OFF
Front wiper stops at fail-safe opera-
tion
BLOCK
ST RLY REQ Ignition switch OFF or ACC
OFF
Ignition switch START ON
IGN RLY Ignition switch OFF or ACC
OFF
Ignition switch ON ON
RR DEF REQ Rear defogger switch OFF
OFF
Rear defogger switch ON ON
OIL P SW Ignition switch OFF, ACC or engine running
OPEN
Ignition switch ON CLOSE
DTRL REQ Daytime light system requested OFF with CONSULT-III.
OFF
Daytime light system reques ted ON with CONSULT-III. ON
HOOD SW Hood closed.
OFF
Hood open. ON
Revision: December 20092009 QX56