2009 INFINITI QX56 hood release

ENGINE COOLING FANCO-19
< ON-VEHICLE REPAIR >
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INSTALLATION
Installation is in the reverse order of removal.
• Install cooling fan with its front mark “F” facing front of engine.
INSPECTION AFTER INSTALLATION
• Check for leaks of the engine coolant. Refer to
CO-10, "Inspection".
• Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
Removal and Installati on (Motor Driven Type)INFOID:0000000003771289
REMOVAL
1. Remove the front bumper fascia. Refer to EXT-13, "Removal and Installation".
2. Disconnect the secondary hood release cable.
3. Disconnect harness connector (A) from fan motor.
4. Remove the bolt and remove the fan grille and motor assembly.
INSTALLATION
Installation is in the reverse order of removal.
• Cooling fan is controlled by ECM. For details, refer to EC-36, "
Description".
AWBIA0668ZZ
Revision: December 20092009 QX56

HOOD
DLK-231
< ON-VEHICLE REPAIR > [WITH INTELLIGENT KEY SYSTEM]
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Removal and Installation of Hood Lock ControlINFOID:0000000003775853
REMOVAL
1. Remove the bolts and the hood lock assembly.
2. Remove the front fender protector (LH). Refer to EXT-23, "
Removal and Installation".
3. Disconnect the hood lock primary and secondary hood lock cables from the hood lock. Unclip the primary
cable from the radiator core support upper and hood ledge.
4. Remove the hood lock assembly.
5. Remove the nuts and the secondary hood lock release assembly.
6. Remove the grommet from the dash lower, and pull the primary hood lock cable into the passenger room. CAUTION:
While pulling, be careful not to dama ge the outside of the hood lock cable.
INSTALLATION
1. Pull the hood lock cable through the dash lower hole into the engine room.
Be careful not to bend the cable too much, keeping the radius
100mm (3.94 in) or more.
2. Make sure the cable is not of fset from the positioning grommet,
and push the grommet into the dash lower hole securely.
3. Apply sealant around the grommet at * mark.
1. Hood lock assembly 2. Secondary hood lock release as-
sembly 3. Secondary hood lock cable
4. Primary hood lock cable 5. Grommet6. Hood lock release handle
WIIA0900E
PIIA0173E
Revision: December 20092009 QX56

DLK-232
< ON-VEHICLE REPAIR >[WITH INTELLIGENT KEY SYSTEM]
HOOD
4. Install the primary and secondary cables securely to the hood
lock.
5. Install the hood lock and the secondary hood lock release assemblies.
6. Check the hood lock adjustment and hood opener operation. Refer to DLK-229, "
Fitting Adjustment".
7. Install the remaing componets in the reverse order of removal.
Hood Lock Control InspectionINFOID:0000000003775854
CAUTION:
If the hood lock cable is bent or deformed, replace it.
1. Remove the front grille. Refer to EXT-17, "
Removal and Installation".
2. Make sure the secondary latch is properly engaged with the sec- ondary striker with hood's own weight by dropping it from
approx. 200 mm (7.87 in) height.
3. While operating the hood opener, carefully make sure the front end of the hood is raised by approx. 20 mm (0.79 in). Also make
sure the hood opener returns to the original position.
4. Check the hood lock lubrication condition. If necessary, apply “body grease” to the points shown in the figure.
5. Install the front grille. Refer to EXT-17, "
Removal and Installa-
tion".
Hood Stay DisposalINFOID:0000000005877751
1. Fix hood stay (1) using a vise (C).
2. Using hacksaw (A) slowly make 2 holes in the hood stay, in numerical order as shown in the figure.
CAUTION:
• When cutting a hole on hood stay, always cover a hack-saw using a shop cloth (B) to avoid scattering metal frag-
ments or oil.
• Wear eye protection (safety glasses).
• Wear gloves.
PIIA0174E
PIIA1086E
PIIA0176E
JMKIA3336ZZ
Revision: December 20092009 QX56

P0137, P0157 HO2S2EC-153
< COMPONENT DIAGNOSIS > [VK56DE]
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If not, warm up engine and go to next step when
“COOLAN TEMP/S” indication reaches to 70°C (158 °F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1147” (for DTC P0137) or “HO2S2 (B2) P1167” (for DTC P0157) of “HO2S2” in
“DTC WORK SUPPORT” mode with CONSULT-III.
9. Start engine and following the instruction of CONSULT-III. NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is display ed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-153, "Diagnosis Procedure"
.
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function CheckINFOID:0000000003771418
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and ground.
6. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0. 58V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be above 0. 58V at least once during this
procedure.
8. If NG, go to EC-153, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771419
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
PBIB2054E
BBIA0354E
Revision: December 20092009 QX56

P0139, P0159 HO2S2EC-165
< COMPONENT DIAGNOSIS > [VK56DE]
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If not, warm up engine and go to next step when
“COOLAN TEMP/S” indication reaches to 70°C (158 °F).
7. Open engine hood.
8. Select “HO2S2 (B1) P0139” or “HO2S2 (B2) P 0159” of “HO2S2” in “DTC WORK SUPPORT” mode with
CONSULT-III.
9. Following the instruction of CONSULT-III. NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is display ed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-165, "Diagnosis Procedure"
.
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function CheckINFOID:0000000003771430
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and ground.
6. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
A change of voltage should be more than 0.12V for 1 sec-
ond during this procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
A change of voltage should be more than 0.12V for 1 sec-
ond during this procedure.
8. If NG, go to EC-165, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771431
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
PBIB2054E
BBIA0354E
Revision: December 20092009 QX56

EC-206
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE
WAY CATALYST FUNCTION
P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000003771472
The ECM monitors the switching frequency ratio of air fuel sensor
(A/F) sensor 1 and heat ed oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decr eases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specif ied limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000003771473
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing 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.
WITH CONSULT-III
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “C OOLAN TEMP/S” indication reaches to 70°C (158 °F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “S RT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to “CMPLT” (It
will take approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70 °C (158 °F) and then retest from step 1.
12. Select “SELF-DIAG RESULTS” mode with CONSULT-III.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1) Catalyst system efficien-
cy below threshold  Three way catalyst (manifold) does not oper-
ate properly.
 Three way catalyst (manifold) does not have enough oxygen storage capacity.  Three way catalyst (manifold)
 Exhaust tube
 Intake air leaks
 Fuel injector
 Fuel injector leaks
 Spark plug
 Improper ignition timing
P0430
0430
(Bank 2)
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

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