2011 INFINITI QX56 hood open

EC-250
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0138, P0158 HO2S2
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 2 minutes.
7. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-251, "Diagnosis Procedure".
NO-1 >> With CONSULT-III: GO TO 3.
NO-2 >> With GST: GO TO 5.
3.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B
WITH CONSULT-III
NOTE:
For better results, perform “DTC WORK SU PPORT” at a temperature of 0 to 30°C (32 to 86 °F).
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches 70°C (158 °F).
9. Open engine hood.
10. Select “HO2S2 (B1) P1146” (for DTC P0138) or “HO2S2 (B2) P1166” (for DTC P0158) of “HO2S2” in
“DTC WORK SUPPORT” mode with CONSULT-III.
11. Follow the instruction of CONSULT-III display. NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
12. Touch “SELF-DIAG RESULTS”.
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Go to EC-251, "
Diagnosis Procedure".
CON NOT BE DIAGNOSED>>GO TO 4.
4.PERFORM DTC CONFIRMATION PROC EDURE FOR MALFUNCTION B AGAIN
1. Turn ignition switch OFF and leave the vehi cle in a cool place (soak the vehicle).
2. Perform DTC confirmation procedure again.
>> GO TO 3.
5.PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B
WITH GST
Perform component function check. Refer to EC-251, "
Component Function Check".
NOTE:
Use component function check to check the overall func tion of the heated oxygen sensor 2 circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
Revision: 2010 May2011 QX56

P0139, P0159 HO2S2EC-257
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0139, P0159 HO2S2
DTC LogicINFOID:0000000006217821
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel
ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during various driving conditions
such as fuel cut.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 4.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158 °F).
9. Open engine hood.
10. Select “HO2S2 (B1) P0139” or “HO2S2 (B2) P 0159” of “HO2S2” in “DTC WORK SUPPORT” mode with
CONSULT-III.
11. Start engine and follow the instruction of CONSULT-III display.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
12. Touch “SELF-DIAG RESULTS”.
SEF302U
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0139 HO2S2 (B1)
[Heated oxygen sensor 2
(bank 1) circuit slow response] It takes more time for the sensor to respond
between rich and lean than the specified
time.  Harness or connectors
(The heated oxygen sensor 2 circuit is
open or shorted)
 Heated oxygen sensor 2
 Fuel pressure
 Fuel injector
 Intake air leaks
P0159
HO2S2 (B2)
[Heated oxygen sensor 2
(bank 2) circuit slow response]
Revision: 2010 May2011 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0420, P0430 THREE WAY CATALYST FUNCTION
DTC LogicINFOID:0000000006217851
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F)
sensor 1 and heated 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 A/F sensor 1 and heated oxygen sensor
2 approaches a specified limit value, the three way catalyst (mani-
fold) malfunction is diagnosed.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 6.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
TESTING CONDITION:
Do not maintain engine speed for mo re than the specified minutes below.
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158 °F).
9. Open engine hood.
10. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
11. Rev engine between 2,000 and 3,000 rpm and hold it for 3 consecutive minutes then release the acceler-
ator pedal completely.
12. Check the indication of “CATALYST”.
Which is displayed on CONSULT-III screen?
CMPLT >> GO TO 5.
INCMP >> GO TO 3.
PBIB2055E
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0420 TW CATALYST SYS-B1
[Catalyst system efficiency
below threshold (bank 1)]
 Three way catalyst (manifold) does not
operate properly.
 Three way catalyst (manifold) does not have enough oxygen storage capacity.  Three way catalyst (manifold)
 Exhaust tube
 Intake air leakage
 Fuel injector
 Fuel injector leakage
 Spark plug
 Improper ignition timing
P0430
TW CATALYST SYS-B2
[Catalyst system efficiency
below threshold (bank 2)]
Revision: 2010 May2011 QX56

EC-308
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Wait 5 seconds at idle.
2. Rev engine between 2,000 and 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to “CMPLT” (It will take approximately 5 minutes).
Does the indication change to
“CMPLT”?
YES >> GO TO 5.
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
1. Stop engine and cool it down to less than 70 °C (158 °F).
2. Perform DTC CONFIRMATION PROCEDURE again.
>> GO TO 2.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-309, "Diagnosis Procedure".
NO >> INSPECTION END
6.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform component function check. Refer to EC-308, "
Component Function Check".
NOTE:
Use component function check to check the overall functi on of the three way catalyst (manifold). During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-309, "
Diagnosis Procedure"
Component Function CheckINFOID:0000000006217852
1.PERFORM COMPONENT FUNCTION CHECK
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. Open engine hood.
6. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-309, "
Diagnosis Procedure".
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0420 F110 96
[HO2S2
(bank 1)] 100Keeping engine speed at 2,500 rpm
constant under no load The voltage fluctuation cycle takes more
than 5 seconds.
 1 cycle: 0.6 - 1.0
→ 0 - 0.3 → 0.6 - 1.0
P0430 87
[HO2S2
(bank 2)]
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (IPDM E/R)EXL-27
< SYSTEM DESCRIPTION > [XENON TYPE]
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DIAGNOSIS SYSTEM (IPDM E/R)
Diagnosis DescriptionINFOID:0000000006368066
AUTO ACTIVE TEST
Description
In auto active test, the IPDM E/R sends a drive signal to the following systems to check their operation.
 Oil pressure warning lamp
 Rear window defogger
 Front wiper (LO, HI)
 Parking lamp
 License plate lamp
 Tail lamp
 Side marker lamp
 Front fog lamp
 Headlamp (LO, HI)
 A/C compressor (magnet clutch)
Operation Procedure
CAUTION:
Never perform auto active test in the following conditions.
 Engine is running.
 CONSULT-III is connected.
1. Close the hood and lift the wiper arms from the windshield. (Prevent windshield damage due to wiper
operation)
NOTE:
When auto active test is performed with hood opened, sprinkle water on windshield beforehand.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON, and within 20 seconds, pr ess the driver door switch 10 times. Then turn the
ignition switch OFF.
CAUTION:
Close passenger door.
4. Turn the ignition switch ON within 10 seconds. Af ter that the horn sounds once and the auto active test
starts.
CAUTION:
Engine starts when ignition switch is turned ON while brake pedal is depressed.
5. The oil pressure warning lamp starts blinking when the auto active test starts.
6. After a series of the following operations is repeated 3 times, auto active test is completed.
NOTE:
 When auto active test has to be cancelled halfw ay through test, turn the ignition switch OFF.
 When auto active test is not activated, door swit ch may be the cause. Check door switch. Refer to DLK-117,
"ComponentFunctionCheck".
Inspection in Auto Active Test
When auto active test is actuated, the following operation sequence is repeated 3 times.
Operation
sequence Inspection location Operation
1 Oil pressure warning lamp Blinks continuously during operation of auto active test
2 Rear window defogger 10 seconds
3 Front wiper LO for 5 seconds → HI for 5 seconds
4 Parking lamp
 License plate lamp
 Tail lamp
 Side marker lamp
 Front fog lamp 10 seconds
Revision: 2010 May2011 QX56

EXL-30
< SYSTEM DESCRIPTION >[XENON TYPE]
DIAGNOSIS SYSTEM (IPDM E/R)
ACTIVE TEST
Te s t i t e m
PUSH SW
[Off/On]Displays the status of the push-button ignition switch judged by IPDM E/R.
INTER/NP SW
[Off/On] Displays the status of the shift position judged by IPDM E/R.
ST RLY CONT
[Off/On] Displays the status of the starter relay status signal received from BCM via CAN
communication.
IHBT RLY -REQ
[Off/On] Displays the status of the starter control relay signal received from BCM via CAN
communication.
ST/INHI RLY
[Off/ ST ON/INHI ON/UNKWN] Displays the status of the starter relay and starter control relay judged by IPDM
E/R.
DETENT SW
[Off/On] Displays the status of the A/T shift selector (detention switch) judged by IPDM E/
R.
S/L RLY -REQ
[Off/On] Displays the status of the steering lock relay signal received from BCM via CAN
communication.
S/L STATE
[LOCK/UNLK/UNKWN] Displays the status of the steering lock judged by IPDM E/R.
OIL P SW
[Open/Close] Displays the status of the oil pressure switch judged by IPDM E/R.
HOOD SW
[Off/On] Displays the status of the hood switch judged by IPDM E/R.
HL WASHER REQ
[Off/On] Displays the status of the headlamp washer request signal received from BCM via
CAN communication.
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.
Monitor Item
[Unit] MAIN SIG-
NALS Description
Test item Operation Description
CORNERING LAMP LH
NOTE:
This item is indicated, but cannot be tested.
RH
HORN On Operates horn relay for 20 ms.
REAR DEFOGGER Off OFF
On Operates the 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* 1OFF
2 Transmits 50% pulse duty signal (PWM signal) to the cooling fan control module.
3 Transmits 75% pulse duty signal (PWM signal) to the cooling fan control module.
4
Transmits 100% pulse duty signal (PWM signal) to the cooling fan control mod-
ule.
HEAD LAMP WASHER On Operates the headlamp washer relay for 1 second.
Revision: 2010 May2011 QX56

FRONT BUMPEREXT-13
< REMOVAL AND INSTALLATION >
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Removal and InstallationINFOID:0000000006367598
REMOVAL
CAUTION:
Bumper fascia is made of resin. Never apply strong force to it, and be careful to prevent contact with
oil.
1. Fully open hood assembly.
2. Remove front grille. Refer to EXT-19, "
Removal and Installation".
3. Remove bumper molding. 1. Remove front fender drip cover. Refer to DLK-223, "
FRONT FENDER DRIP COVER : Removal and
Installation".
2. Remove bumper molding upper fixing screws (A) (LH and
RH).
3. Remove bumper molding fixing clips (A).
1. Bumper molding bracket LH 2. Energy absorber LH 3. Rivet
4. Bumper molding 5. Grommet 6. Bumper molding bracket RH
7. Energy absorber RH 8. Bumper fascia assembly 9. Front fog lamp RH
10. Front fog lamp finisher RH 11. Front grille lower molding 12. Front bumper grille (with ICC)
13. Front bumper grille (without ICC) 14. License plate bracket 15. Front fog lamp finisher LH
16. Front fog lamp LH 17. U nut 18. Bumper retainer bracket LH
19. Bumper retainer 20. Bumper side bracket LH 21. Grommet
22. Bumper side bracket RH 23. Grommet 24. Bumper molding stay RH
25. Bumper retainer bracket RH 26. Bumper retainer bracket CTR 27. Bumper molding stay LH
28. double-sided tape [t: 0.13 mm (0.005 in)]
: Pawl
: Metal clip
: Vehicle front
JMKIA5426ZZ
JMKIA5427ZZ
Revision: 2010 May2011 QX56

FRONT GRILLEEXT-19
< REMOVAL AND INSTALLATION >
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FRONT GRILLE
Exploded ViewINFOID:0000000006367601
Removal and InstallationINFOID:0000000006367602
REMOVAL
1. Fully open hood assembly.
2. Apply protective tape (A) on surrounding area of front grille (1).
3. Remove front grille upper fixing clips.
1. Front grille 2. Front emblem : Pawl
JMKIA5462ZZ
JMKIA5424ZZ
JMKIA5423ZZ
Revision: 2010 May2011 QX56