2008 INFINITI QX56 sensor

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-215
< COMPONENT DIAGNOSIS > [VK56DE]
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P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000001351568
The ECM monitors the switching
frequency ratio of air fuel sensor
(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 decreases, 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 specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000001351569
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
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 “COOLAN TEMP/S” indication reaches to 70°C (158° F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT 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 unt il “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 RESU LTS” mode with CONSULT-III.
13. Confirm that the 1st trip DTC is not detected. If the 1st trip DTC is detected, go to EC-216, "
Diagnosis Procedure".
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: March 2010
2008 QX56

EC-216
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE WAY CATALYST FUNCTION
Overall Function Check
INFOID:0000000001351570
Use this procedure to check the overall function of the th ree way catalyst (manifold). 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. Open engine hood.
6. Set voltmeter probes between ECM terminals ECM terminals 55 [HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) signal] and
ground.
7. Keep engine speed at 2,500 rpm constant under no load.
8. Make sure that the voltage does not vary for more than 5 sec- onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to
EC-216, "
Diagnosis Procedure".
• 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
Diagnosis ProcedureINFOID:0000000001351571
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK IGNITION TIMING
Check the following items. Refer to EC-13, "
Basic Inspection".
PBIB2056E
PBIB1216E
Revision: March 2010 2008 QX56

P0441 EVAP CONTROL SYSTEMEC-219
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P0441 EVAP CONTROL SYSTEM
System DescriptionINFOID:0000000001351572
NOTE:
If DTC P0441 is displayed with
other DTC such as P2122, P2123, P2127, P2128 or P2138, first perform
trouble diagnosis for other DTC.
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
On Board Diagnosis LogicINFOID:0000000001351573
Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow
are adequate. If not, a malfunction is determined.
DTC Confirmation ProcedureINFOID:0000000001351574
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41° F) or more.
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
PBIB1026E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0441
0441 EVAP control system in-
correct purge flow EVAP control system does not operate proper-
ly, EVAP control system has a leak between in-
take manifold and EVAP control system
pressure sensor. • EVAP canister purge volume control so-
lenoid valve stuck closed
• EVAP control system pressure sensor
and the circuit
• Loose, disconnected or improper con- nection of rubber tube
• Blocked rubber tube
• Cracked EVAP canister
• EVAP canister purge volume control so- lenoid valve circuit
• Accelerator pedal position sensor
• Blocked purge port
• EVAP canister vent control valve
Revision: March 2010 2008 QX56

EC-220
< COMPONENT DIAGNOSIS >[VK56DE]
P0441 EVAP CONTROL SYSTEM
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE
SYSTEM” in “DTC WORK SUPPORT” mode with CON-
SULT-III.
5. Touch “START”. If “COMPLETED” is displayed, go to step 7.
6. 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.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “ SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
220, "Diagnosis Procedure".
Overall Function CheckINFOID:0000000001351575
Use this procedure to check the overall monitoring func tion of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
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, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system pressure sensor signal) and ground.
6. Check EVAP control system pre ssure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1 minute.
8. Verify that EVAP control system pressure sensor va lue stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
9. If NG, go to EC-220, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001351576
1.CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-III)>>GO TO 2.
OK (Without CONSULT-III)>>GO TO 3.
NG >> Replace EVAP canister.
2.CHECK PURGE FLOW
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 12.0 msec
COOLAN TEMP/S 0 - 119°C (32 - 246 °F)
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB1109E
Revision: March 2010 2008 QX56

EC-222
< COMPONENT DIAGNOSIS >[VK56DE]
P0441 EVAP CONTROL SYSTEM
3. Check that air flows freely.
OK or NG
OK (With CONSULT-III)>>GO TO 6.
OK (Without CONSULT-III)>>GO TO 7.
NG >> Repair or clean hoses and/or purge port.
6.CHECK EVAP CANISTER PURGE VO
LUME CONTROL SOLENOID VALVE
With CONSULT-III
1. Start engine.
2. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with CONSULT-III. Check that engine speed var- ies according to the valve opening.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.CHECK EVAP CANISTER PURGE VO LUME CONTROL SOLENOID VALVE
Refer to EC-238, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP canister purge volume control solenoid valve.
8.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP control system pressure sensor.
9.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR FUNCTION
Refer to DTC Confirmation Procedure for DTC P0452, EC-250, "
DTC Confirmation Procedure" and P0453,
EC-254, "
DTC Confirmation Procedure".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EV AP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 11.
NG >> Clean the rubber tube using an air blower.
11 .CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-241, "
Component Inspection".
OK or NG
OK >> GO TO 12.
NG >> Replace EVAP canister vent control valve.
12.CHECK EVAP PURGE LINE
SEF368U
Water should not exist.
Revision: March 2010 2008 QX56

EC-224
< COMPONENT DIAGNOSIS >[VK56DE]
P0442 EVAP CONTROL SYSTEM
P0442 EVAP CONTROL SYSTEM
On Board Diagn
osis LogicINFOID:0000000001351577
This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.
If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister
purge volume control solenoid valve, under the following “Vacuum test” conditions.
The EVAP canister vent control valve is closed to shut the EVAP purge line off. The EVAP canister purge vol-
ume control solenoid valve will then be opened to depressurize the EVAP purge line using intake manifold
vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.
CAUTION:
• Use only a genuine NISSAN fuel filler cap as a replacemen t. If an incorrect fuel filler cap is used, the
MIL may come on.
• If the fuel filler cap is not tigh tened properly, the MIL may come on.
• Use only a genuine NISSAN rubber tube as a replacement.
DTC Confirmation ProcedureINFOID:0000000001351578
NOTE:
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0442
0442 EVAP control system
small leak detected
(negative pressure) EVAP control system has a leak, EVAP
control system does not operate prop-
erly. • Incorrect fuel tank vacuum relief valve
• Incorrect fuel filler cap used
• Fuel filler cap remains open or fails to close.
• Foreign matter caught in fuel filler cap.
• Leak is in line between intake manifold and EVAP
canister purge volume control solenoid valve.
• Foreign matter caught in EVAP canister vent con- trol valve.
• EVAP canister or fuel tank leaks
• EVAP purge line (pipe and rubber tube) leaks
• EVAP purge line rubber tube bent
• Loose or disconnected rubber tube
• EVAP canister vent control valve and the circuit
• EVAP canister purge volume control solenoid valve and the circuit
• Fuel tank temperature sensor
• O-ring of EVAP canister vent control valve is missing or damaged
• EVAP canister is saturated with water
• EVAP control system pressure sensor
• Fuel level sensor and the circuit
• Refueling EVAP vapor cut valve
• ORVR system leaks
PBIB1026E
Revision: March 2010 2008 QX56

P0442 EVAP CONTROL SYSTEMEC-227
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details.
Refer to EC-37, "
Description" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
7.CHECK FOR EVAP LEAK
Without CONSULT-III
1. Turn ignition switch OFF.
2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts
until the end of test.)
3. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg), then remove pump and EVAP service port adapter.
CAUTION:
• Never use compressed air or a high pressure pump.
• Do not exceed 4.12 kPa (0.042 kg/cm
2 , 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details. Refer
to EC-37, "
Description" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
8.CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
• EVAP canister vent control valve is installed properly. Refer to EC-498, "
Removal and Installation" .
• EVAP canister vent control valve. Refer to EC-241, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace EVAP canister vent control valve and O-ring.
9.CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent c ontrol valve and EVAP control system pressure sensor
attached.
SEF200U
BBIA0443E
SEF200U
Revision: March 2010 2008 QX56

EC-228
< COMPONENT DIAGNOSIS >[VK56DE]
P0442 EVAP CONTROL SYSTEM
2. Does water drain from the EVAP canister?
Ye s o r N o
Yes >> GO TO 10.
No (With CONSULT-III)>>GO TO 12.
No (Without CONSULT-III)>>GO TO 13.
10.CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK (With CONSULT-III)>>GO TO 12.
OK (Without CONSULT-III)>>GO TO 13.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• EVAP canister for damage
• EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
12.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-III
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V ” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-III screen to increase “PURG VOL CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
13.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 16.
NG >> GO TO 14.
14.CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to EC-37, "
Description".
OK or NG
BBIA0351E
Vacuum should exist.
Vacuum should exist.
Revision: March 2010 2008 QX56