2011 INFINITI QX56 Fuel

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
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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

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-309
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Diagnosis ProcedureINFOID:0000000006217853
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dents.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
2.CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before the three way catalyst (manifold).
Is exhaust gas leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 3.
3.CHECK INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 4.
4.CHECK IDLE SPEED AND IGNITION TIMING
Check idle speed and ignition timing.
For procedure, refer to EC-530, "
Inspection" and EC-531, "Inspection".
For specification, refer to EC-538, "
Idle Speed" and EC-538, "Ignition Timing".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Follow the EC-139, "
Work Procedure".
5.CHECK FUEL INJECTORS
Refer to EC-498, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform EC-498, "
Diagnosis Procedure".
6.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
 For the fuse number, refer to EC-114, "
Wiring Diagram".
 For the fuse arrangement, refer to PG-140, "
Fuse, Connector and Terminal Arrangement".
 Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following
procedure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
5. Turn ignition switch OFF.
PBIB1216E
Revision: 2010 May2011 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-311
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NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to
EM-132, "Spar k
Plug".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly. Refer to EM-49, "
Removal and Installation".
Keep fuel hose and all fuel injectors connected to fuel tube.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
6. Check that fuel does not drip from fuel injector.
Does fuel drip from fuel injector?
YES >> Replace the fuel injector(s) from which fuel is dripping.
NO >> GO TO 11.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace three way catalyst assembly.
NO >> Repair or replace harness or connector.
Revision: 2010 May2011 QX56

P0441 EVAP CONTROL SYSTEMEC-313
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WITH CONSULT-III
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
1. Start engine and warm it up to 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 let it idle for at least 70 seconds.
6. Select “PURG FLOW P0441” of “EVAPORATIVE SYS TEM” in “DTC WORK SUPPORT” mode with CON-
SULT-III.
7. Touch “START”.
Is
“COMPLETED” displayed on CONSULT-III screen?
YES >> GO TO 4.
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
When the following conditions are met, “TESTING” will be displayed on the CONSULT-III screen. Maintain the
conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “TESTING” does not change for a long time, retry from step 2.
Is
“COMPLETED” displayed on CONSULT-III screen?
YES >> GO TO 4.
NO >> Perform DTC CONFIRMATION PROCEDURE again. GO TO 2.
4.PERFORM DTC CONFIRMATION PROCEDURE-III
Touch “SELF-DIAG RESULTS”.
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Proceed to EC-314, "
Diagnosis Procedure".
5.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform component function check. Refer to EC-313, "
Component Function Check".
NOTE:
Use component function check to check the overall m onitoring function of the EVAP control system purge flow
monitoring. During this check, a 1s t trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-314, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006288305
1.PERFORM COMPONENT FUNCTION CHECK
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.3 - 9.0 msec
COOLAN TEMP/S More than 0 °C (32 °F)
Revision: 2010 May2011 QX56

P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-317
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE
DTC LogicINFOID:0000000006288307
DTC DETECTION LOGIC
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.
TESTING CONDITION:
 Perform “DTC CONFIRMATION PROCEDURE” when the fuel level is between 1/4 and 3/4 full, and
vehicle is placed on flat level surface.
 Always perform test at a temperature of 5 to 60 °C (41 to 140 °F).
 Cool the vehicle so that engi ne coolant temperature becomes same level as ambient temperature.
Do you have CONSULT-III
YES >> GO TO 2.
NO >> GO TO 4.
2.PERFORM DTC CONFIRMATION PROCEDURE A
WITH CONSULT-III
1. Turn ignition switch ON.
2. Check that the following condition are met. FUEL T/TMP SE: 0 - 35 °C (32 - 95 °F)
3. Start engine and wait at least 60 seconds.
4. Check 1st trip DTC.
IS 1st trip DTC detected?
OK >> Proceed to EC-318, "Diagnosis Procedure".
NG >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE B
WITH CONSULT-III
1. Start engine and warm it up to 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. Turn ignition switch ON.
6. Select “PURG VOL CN/V P1444” of “EVAPORA TIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-III.
7. Touch “START”.
8. Start engine and let it idle until “TESTING” on CO NSULT-III changes to “COMPLETED”. (It will take
approximately 10 seconds.)
If “TESTING” is not displayed afte r 5 minutes, retry from step 2.
9. Touch “SELF-DIAG RESULTS”.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0443 PURG VOLUME CONT/V
(EVAP canister purge vol-
ume control solenoid valve) A
The canister purge flow is detected dur-
ing the vehicle is stopped while the en-
gine is running, even when EVAP
canister purge volume control solenoid
valve is completely closed.  EVAP control system pressure sensor
 EVAP canister purge volume control
solenoid valve
(The valve is stuck open.)
 EVAP canister vent control valve
 EVAP canister
 Hoses (Hoses are connected incorrectly or
clogged.)
B
The canister purge flow is detected dur-
ing the specified driving conditions, even
when EVAP canister purge volume con-
trol solenoid valve is completely closed.
Revision: 2010 May2011 QX56

EC-318
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P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Proceed to
EC-318, "
Diagnosis Procedure".
4.PERFORM DTC CONFIRMATION PROCEDURE A
WITH GST
1. Turn ignition switch ON.
2. Set voltmeter probes to ECM harness connector terminals.
3. Start engine and wait at least 60 seconds.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-318, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE B
WITH GST
1. Start engine and warm it up to 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 let it idle for at least 20 seconds.
6. Check 1st trip DTC.
Is 1st trip DTC displayed?
YES >> Proceed to EC-318, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288308
1.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
3. Turn ignition switch ON.
4. Check the voltage between EVAP canister purge vo lume control solenoid valve harness connector and
ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between EVAP canister purge volume control solenoid valve and IPDM E/R
 Harness for open or short between EVAP canister purge volume control solenoid valve and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
ECM Voltage (V)
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
(Sensor ground) 3.1 - 4.0
EVAP canister purge volume control solenoid valve
Ground Voltage
Connector Terminal
F48 1 Ground Battery voltage
Revision: 2010 May2011 QX56

EC-336
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0452 EVAP CONTROL S
YSTEM PRESSURE SENSOR
P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
DTC LogicINFOID:0000000006288319
DTC DETECTION LOGIC
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.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and warm it up to 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. Turn ignition switch ON.
6. Select “DATA MONITOR” mode with CONSULT-III.
7. Check that “FUEL T/TM P SE” is more than 0°C (32 °F).
8. Start engine and wait at least 20 seconds.
9. Check 1st trip DTC.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes to ECM harness connector terminals under the following conditions.
3. Check that the voltage is less than 4.2 V.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Turn ignition switch OFF and wait at least 10 seconds.
7. Start engine and wait at least 20 seconds.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0452 EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor low input) An excessively low voltage from
the sensor is sent to ECM.  (EVAP control system pressure sensor circuit is short-
ed.)
Harness or connectors
(Battery current sensor circuit is open or shorted.)
(Accelerator pedal position sensor 2 circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Battery current sensor
 Accelerator pedal position sensor
 Camshaft position sensor (bank 1)
 Crankshaft position sensor
 Refrigerant pressure sensor
ECM
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
Revision: 2010 May2011 QX56

P0453 EVAP CONTROL SYSTEM PRESSURE SENSOREC-341
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P0453 EVAP CONTROL SYSTEM
PRESSURE SENSOR
DTC LogicINFOID:0000000006288322
DTC DETECTION LOGIC
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.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and warm it up to 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. Turn ignition switch ON.
6. Select “DATA MONITOR” mode with CONSULT-III.
7. Check that “FUEL T/TM P SE” is more than 0°C (32 °F).
8. Start engine and wait at least 20 seconds.
9. Check 1st trip DTC.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes to ECM harness connector terminals under the following conditions.
3. Check that the voltage is less than 4.2 V.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0453 EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor high input) An excessively high voltage
from the sensor is sent to
ECM.  Harness or connectors
(EVAP control system pressure sensor circuit is short-
ed.)
(Crankshaft position sensor circuit is open or shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Accelerator pedal position sensor 2 circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Crankshaft position sensor
 Camshaft position sensor (bank 1)
 Accelerator pedal position sensor 2
 Battery current sensor
 Refrigerant pressure sensor
 EVAP canister vent control valve
 EVAP canister
 Rubber hose from EVAP canister vent control valve to
vehicle frame
ECM Ground
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
Revision: 2010 May2011 QX56