2004 INFINITI QX56 display

DTC P1276, P1286 A/F SENSOR 1
EC-465
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Revision: August 20072004 QX56
7. Repeat steps 2 to 3 five times.
8. Stop the vehicle and connect GST to the vehicle.
9. Make sure that no DTC is displayed.
If the DTC is displayed, go to EC-469, "
Diagnostic Procedure" .

DTC P1278, P1288 A/F SENSOR 1
EC-473
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Revision: August 20072004 QX56
DTC Confirmation ProcedureUBS00HAI
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:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to 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 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.
6. Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.
7. After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to EC-
123, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
8. Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.
9. Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to
EC-123, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE"
.
10. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to EC-478, "
Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select “MODE 1” with GST.
3. Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
PBIB0756E
PBIB1925E
PBIB0758E

EC-474Revision: August 2007
DTC P1278, P1288 A/F SENSOR 1
2004 QX56

Intake air leaks

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Injectors

Incorrect PCV hose connection

PCV valve

Mass air flow sensor
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 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select “MODE 7” with GST.
If the 1st trip DTC is displayed, go to EC-478, "
Diagnostic Procedure" .

EC-480Revision: August 2007
DTC P1278, P1288 A/F SENSOR 1
2004 QX56
5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”
or “START”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-208 or EC-217
.
No >> GO TO 6.
SEF 9 68 Y
BBIA0368E

DTC P1279, P1289 A/F SENSOR 1
EC-485
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EC
Revision: August 20072004 QX56
DTC Confirmation ProcedureUBS00HAP
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:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to 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 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.
6. Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.
7. After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to EC-
123, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
8. Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.
9. Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to
EC-123, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE"
.
10. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to EC-490, "
Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select “MODE 1” with GST.
3. Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
PBIB0756E
PBIB1925E
PBIB0758E

EC-486Revision: August 2007
DTC P1279, P1289 A/F SENSOR 1
2004 QX56

Intake air leaks

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Injectors

Incorrect PCV hose connection

PCV valve

Mass air flow sensor
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 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select “MODE 7” with GST.
If the 1st trip DTC is displayed, go to EC-490, "
Diagnostic Procedure" .

EC-492Revision: August 2007
DTC P1279, P1289 A/F SENSOR 1
2004 QX56
5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”
or “START”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-208 or EC-217
.
No >> GO TO 6.
SEF 9 68 Y
BBIA0368E

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
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Revision: August 20072004 QX56
On Board Diagnosis LogicUBS00HAV
DTC Confirmation ProcedureUBS00HAW
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-II
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. Select “PURG VOL CN/V P1444” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-II.
5. Touch “START”.
6. Start engine and let it idle until “TESTING” on CONSULT-II changes to “COMPLETED”. (It will take
approximately 10 seconds.)
If “TESTING” is not displayed after 5 minutes, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
500, "Diagnostic Procedure" .
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. Start engine and let it idle for at least 20 seconds.
4. Select MODE 7 with GST.
5. If 1st trip DTC is detected, go to EC-500, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1444
1444EVAP canister purge
volume control solenoid
valveThe canister purge flow is detected during the
specified driving conditions, 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.)
PBIB0839E