display INFINITI QX56 2004 Factory Service Manual

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
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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

EC-510Revision: August 2007
DTC P1564 ICC STEERING SWITCH
2004 QX56
DTC P1564 ICC STEERING SWITCHPFP:25551
Component DescriptionUBS00HYP
ICC steering switch has variant values of electrical resistance for
each button. ECM reads voltage variation of switch, and determines
which button is operated.
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HYQ
Specification data are reference values.
On Board Diagnosis LogicUBS00HYR

This self-diagnosis has the one trip detection logic.

The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to
EC-351, "
DTC P0605 ECM" .
DTC Confirmation ProcedureUBS00HYS
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.
BBIA0469E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW

Ignition switch: ON
ON/OFF (MAIN) switch: Pressed ON

ON/OFF (MAIN) switch: Released OFF
CANCEL SW

Ignition switch: ON
CANCEL switch: Pressed ON

CANCEL switch: Released OFF
RESUME/ACC SW

Ignition switch: ON
ACCEL/RESUME switch: Pressed ON

ACCEL/RESUME switch: Released OFF
SET SW

Ignition switch: ON
COAST/SET switch: Pressed ON

COAST/SET switch: Released OFF
DIST SW

Ignition switch: ON
DISTANCE switch: Pressed ON

DISTANCE switch: Released OFF
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1564
1564ICC steering switch

An excessively high voltage signal from the
ICC steering switch is sent to ECM.

ECM detects that input signal from the ICC
steering switch is out of the specified range.

ECM detects that the ICC steering switch is
stuck ON.

Harness or connectors
(The switch circuit is open or shorted.)

ICC steering switch

ECM

DTC P1564 ASCD STEERING SWITCH
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Revision: August 20072004 QX56
DTC P1564 ASCD STEERING SWITCHPFP:25551
Component DescriptionUBS00HB8
ASCD steering switch has variant values of electrical resistance for
each button. ECM reads voltage variation of switch, and determines
which button is operated.
Refer to EC-647, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HB9
Specification data are reference values.
On Board Diagnosis LogicUBS00HBA
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to
EC-351, "
DTC P0605 ECM" .
BBIA0362E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW

Ignition switch: ONON/OFF(MAIN) switch: Pressed ON
ON/OFF(MAIN) switch: Released OFF
CANCEL SW

Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW

Ignition switch: ONACCEL/RESUME switch: Pressed ON
ACCEL/RESUME switch: Released OFF
SET SW

Ignition switch: ONCOAST/SET switch: Pressed ON
COAST/SET switch: Released OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1564
1564ASCD steering switch

An excessively high voltage signal from the
ASCD steering switch is sent to ECM.

ECM detects that input signal from the ASCD
steering switch is out of the specified range.

ECM detects that the ASCD steering switch is
stuck ON.

Harness or connectors
(The switch circuit is open or shorted.)

ASCD steering switch

ECM

EC-524Revision: August 2007
DTC P1568 ICC FUNCTION
2004 QX56
DTC P1568 ICC FUNCTIONPFP:18995
On Board Diagnosis LogicUBS00HYW
NOTE:

If DTC P1568 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-135, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1568 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-351, "
DTC P0605 ECM".

This self-diagnosis has the one trip detection logic.

The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureUBS00HYX
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.
Step 4 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press ON/OFF (MAIN) switch on ICC steering switch.
4. Drive the vehicle at more than 40 km/h (25 MPH).
5. Press COAST/SET switch.
6. If DTC is detected, go to EC-524, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00HYY
1. REPLACE ICC UNIT
1. Replace ICC unit.
2. Perform ACS-9, "
ACTION TEST" .
3. Check DTC of ICC unit. Refer to ACS-36, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
>>INSPECTION END
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1568
1568ICC functionECM detects a difference between signals
from ICC unit is out of specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

ICC unit

ECM
SEF 0 58 Y

DTC P1572 ICC BRAKE SWITCH
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Revision: August 20072004 QX56
DTC P1572 ICC BRAKE SWITCHPFP:25320
Component DescriptionUBS00HYZ
When the brake pedal is depressed, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal).
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HZ0
Specification data are reference values.
On Board Diagnosis LogicUBS00HZ1
NOTE:

If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-351, "
DTC P0605 ECM" .

This diagnosis has the one trip detection logic.

The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureUBS00HZ2
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:
Steps 3 and 4 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine.
BBIA0470E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ICC brake switch)

Ignition switch: ON
Brake pedal: Fully released ON

Brake pedal: Slightly depressed OFF
BRAKE SW2
(stop lamp switch)

Ignition switch: ON
Brake pedal: Fully released OFF

Brake pedal: Slightly depressed ON
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1572
1572ICC brake switchON signals from the stop lamp switch and the
ICC brake switch are sent to ECM at the same
time.

Harness or connectors
(The stop lamp switch circuit is open or
shorted.)

Harness or connectors
(The ICC brake switch circuit is open or
shorted.)

Stop lamp switch

ICC brake switch

ICC brake hold relay

Incorrect stop lamp switch installation

Incorrect ICC brake switch installation

ECM