2004 INFINITI QX56 fuel cap

DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-267
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
DTC P0420, P0430 THREE WAY CATALYST FUNCTIONPFP:20905
On Board Diagnosis LogicUBS00H4F
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 ProcedureUBS00H4G
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-II
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-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
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.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1)
Catalyst system effi-
ciency 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)
SEF 1 89 Y

EC-276Revision: August 2007
DTC P0442 EVAP CONTROL SYSTEM
2004 QX56
DTC P0442 EVAP CONTROL SYSTEMPFP:14950
On Board Diagnosis LogicUBS00H4O
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.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0442
0442EVAP 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
control 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

DTC P0442 EVAP CONTROL SYSTEM
EC-277
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
CAUTION:

Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.

If the fuel filler cap is not tightened properly, the MIL may come on.

Use only a genuine NISSAN rubber tube as a replacement.
DTC Confirmation ProcedureUBS00H4P
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:

Perform “DTC WORK SUPPORT” 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 0 to 30°C (32 to 86°F).
WITH CONSULT-II
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
4. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70°C (32 - 158°F)
INT/A TEMP SE: 0 - 30°C (32 - 86°F)
5. Select “EVAP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-79, "
Basic Inspection" .
6. Make sure that “OK” is displayed.
If “NG” is displayed, refer to EC-278, "
Diagnostic Procedure" .
NOTE:
Make sure that EVAP hoses are connected to EVAP canister
purge volume control solenoid valve properly.
WITH GST
NOTE:
Be sure to read the explanation of EC-59, "
Driving Pattern" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-59, "
Driving Pattern" .
PBIB0829E
SEC7 63 C

EC-278Revision: August 2007
DTC P0442 EVAP CONTROL SYSTEM
2004 QX56
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select MODE 7 with GST.
–If P0442 is displayed on the screen, go to EC-278, "Diagnostic Procedure" .
–If P0441 is displayed on the screen, go to EC-273, "Diagnostic Procedure" .
Diagnostic ProcedureUBS00H4Q
1. CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2. CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3. CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-636, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF 9 15 U

EC-316Revision: August 2007
DTC P0455 EVAP CONTROL SYSTEM
2004 QX56
DTC P0455 EVAP CONTROL SYSTEMPFP:14950
On Board Diagnosis LogicUBS00H5Q
This diagnosis detects a very large leak (fuel filler cap fell off etc.) in EVAP system between the fuel tank and
EVAP canister purge volume control solenoid valve.
CAUTION:

Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.

If the fuel filler cap is not tightened properly, the MIL may come on.

Use only a genuine NISSAN rubber tube as a replacement.
PBIB1026E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0455
0455EVAP control system
gross leak detectedEVAP control system has a very large leak
such as fuel filler cap fell off, EVAP control
system does not operate properly.

Fuel filler cap remains open or fails to
close.

Incorrect fuel tank vacuum relief valve

Incorrect fuel filler cap used

Foreign matter caught in fuel filler cap.

Leak is in line between intake manifold and
EVAP canister purge volume control sole-
noid valve.

Foreign matter caught in EVAP canister
vent control 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 sole-
noid valve and the circuit

Fuel tank temperature sensor

O-ring of EVAP canister vent control valve
is missing or damaged.

EVAP control system pressure sensor

Refueling EVAP vapor cut valve

ORVR system leaks

DTC P0455 EVAP CONTROL SYSTEM
EC-317
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
DTC Confirmation ProcedureUBS00H5R
CAUTION:
Never remove fuel filler cap during the DTC Confirmation Procedure.
NOTE:

Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid valve
properly.

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:

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-II
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-II.
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 “EVAP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-79, "
Basic Inspection" .
7. Make sure that “OK” is displayed.
If “NG” is displayed, select “SELF-DIAG RESULTS” mode and
make sure that “EVAP GROSS LEAK [P0455]” is displayed. If it
is displayed, refer to EC-318, "
Diagnostic Procedure" .
If P0442 is displayed, perform Diagnostic Procedure for DTC
P0442 EC-278, "
Diagnostic Procedure" .
PBIB0829E
SEC7 63 C

EC-318Revision: August 2007
DTC P0455 EVAP CONTROL SYSTEM
2004 QX56
WITH GST
NOTE:
Be sure to read the explanation of EC-59, "
Driving Pattern" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-59, "
Driving Pattern" .
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select MODE 7 with GST.

If P0455 is displayed on the screen, go to EC-318, "Diagnostic Procedure" .

If P0442 is displayed on the screen, go to EC-278, "Diagnostic Procedure" .

If P0441 is displayed on the screen, go to EC-273, "Diagnostic Procedure" .
Diagnostic ProcedureUBS00H5S
1. CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2. CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3. CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-636, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF 9 15 U

EC-324Revision: August 2007
DTC P0456 EVAP CONTROL SYSTEM
2004 QX56
DTC P0456 EVAP CONTROL SYSTEMPFP:14950
On Board Diagnosis LogicUBS00H5T
This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume
control solenoid valve, using the intake manifold vacuum in the same way as conventional EVAP small leak
diagnosis.
If ECM judges a leak which corresponds to a very small leak, the very small leak P0456 will be detected.
If ECM judges a leak equivalent to a small leak, EVAP small leak P0442 will be detected.
If ECM judges there are no leaks, the diagnosis will be OK.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0456
0456Evaporative emission
control system very
small leak (negative
pressure check)

EVAP system has a very small leak.

EVAP 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 miss-
ing or damaged

EVAP canister is saturated with water

EVAP control system pressure sensor

Refueling EVAP vapor cut valve

ORVR system leaks

Fuel level sensor and the circuit

Foreign matter caught in EVAP canister purge vol-
ume control solenoid valve
PBIB1026E