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![INFINITI QX56 2010 Factory Service Manual EC-384
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P2A00, P2A03 A/F SENSOR 1
1. Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an INFINITI QX56 2010 Factory Service Manual EC-384
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
1. Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an](/manual-img/42/57032/w960_57032-1736.png)
EC-384
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
1. Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. 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?
Without CONSULT-III
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-459, "
DTC Index".
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-172
or EC-177.
No >> GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF. Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E
BBIA0368E
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![INFINITI QX56 2010 Factory Service Manual P2A00, P2A03 A/F SENSOR 1EC-385
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2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
OK or NG
OK >> GO INFINITI QX56 2010 Factory Service Manual P2A00, P2A03 A/F SENSOR 1EC-385
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2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
OK or NG
OK >> GO](/manual-img/42/57032/w960_57032-1737.png)
P2A00, P2A03 A/F SENSOR 1EC-385
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2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness connector.
6.CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between A/F sensor 1 terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E5, F14
• IPDM E/R harness connector E119
• 15A fuse (No. 54)
• Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows. Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.Water should not exit.
BBIA0376E
Voltage: Battery voltage
PBIB3308E
A/F sensor 1 terminal
ECM terminal
Bank1 13
5
25 6
Bank 2 11
6
27 5
Continuity should exist.
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![INFINITI QX56 2010 Factory Service Manual EC-386
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P2A00, P2A03 A/F SENSOR 1
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in har INFINITI QX56 2010 Factory Service Manual EC-386
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P2A00, P2A03 A/F SENSOR 1
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in har](/manual-img/42/57032/w960_57032-1738.png)
EC-386
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK A/F SENSOR 1 HEATER
Refer to EC-97, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10.CHECK INTERMITTENT INCIDENT
Perform GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
11 .REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
CAUTION:
• Discard any A/F sensor which has been dropped from a height of more than 0.5 m (1.6 ft) onto a hard surface such as a concrete floor; use a new one.
• Before installing new A/F sensor, clean exhau st system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> GO TO 12.
12.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “” in “D ATA MONITOR” mode with CONSULT-III.
3. Make sure that “0.000” is displayed on CONSULT-III screen.
OK or NG
OK >> INSPECTION END
NG >> GO TO 13.
13.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 13 511 6
25 627 5
Continuity should not exist.
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P2A00, P2A03 A/F SENSOR 1EC-387
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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-55, "
Malfunction Indicator
Lamp (MIL)".
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
14.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-III.
3. Make sure that “0.000” is displayed on CONSULT-III screen.
>>INSPECTION END
BBIA0368E
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![INFINITI QX56 2010 Factory Service Manual EC-388
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000005149464
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp INFINITI QX56 2010 Factory Service Manual EC-388
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000005149464
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp](/manual-img/42/57032/w960_57032-1740.png)
EC-388
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000005149464
When the brake pedal is depressed, ASCD 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
EC-33
for the ASCD function.
Diagnosis ProcedureINFOID:0000000005149465
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> INSPECTION END.
NG >> GO TO 2.
2.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
BBIA0373E
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITIONVOLTAGE
Brake pedal: Slightly depressed Approximately 0 V
Brake pedal: Fully released Battery voltage
MBIB0061E
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2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD br INFINITI QX56 2010 Factory Service Manual ASCD BRAKE SWITCHEC-389
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2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD br](/manual-img/42/57032/w960_57032-1741.png)
ASCD BRAKE SWITCHEC-389
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2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and
ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) connector M4
• 10 A fuse (No. 15)
• Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ASCD BRAKE SWITCH INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD BRAKE SWITCH
Refer to EC-390, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace ASCD brake switch.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
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EC-390
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
Component Inspection
INFOID:0000000005149466
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals 1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-15,
"Inspection and Adjustment", and perform step 3 again.
ConditionContinuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
PBIB1536E
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![INFINITI QX56 2010 Factory Service Manual ASCD INDICATOREC-391
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ASCD INDICATOR
Component DescriptionINFOID:0000000005149467
ASCD indicator lamp illuminates to indicate ASCD opera INFINITI QX56 2010 Factory Service Manual ASCD INDICATOREC-391
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ASCD INDICATOR
Component DescriptionINFOID:0000000005149467
ASCD indicator lamp illuminates to indicate ASCD opera](/manual-img/42/57032/w960_57032-1743.png)
ASCD INDICATOREC-391
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ASCD INDICATOR
Component DescriptionINFOID:0000000005149467
ASCD indicator lamp illuminates to indicate ASCD operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when MAIN switch on ASCD st
eering switch is turned ON to indicate that ASCD
system is ready for operation.
SET indicator illuminates when following conditions are met.
• CRUISE indicator is illuminated.
• SET/COAST switch on ASCD steering switch is tur ned ON while vehicle speed is within the range of ASCD
setting.
SET indicator remains lit during ASCD control.
Refer to EC-33
for the ASCD function.
Diagnosis ProcedureINFOID:0000000005149468
1.CHECK OVERALL FUNCTION
Check ASCD indicator under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK DTC
Check that DTC UXXXX is not displayed.
OK or NG
OK >> GO TO 3.
NG >> Perform trouble diagnosis for DTC UXXXX.
3.CHECK COMBINATION METER FUNCTION
Refer to MWI-5
.
OK or NG
OK >> GO TO 4.
NG >> Go to MWI-5
.
4.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
ASCD INDICATOR CONDITIONSPECIFICATION
CRUISE LAMP • Ignition switch: ON • MAIN switch: Pressed at the 1st
time → at the 2nd time ON
→ OFF
SET LAMP • MAIN switch: ON
• When vehicle speed is between
40 km/h (25 MPH) and 144 km/h
(89 MPH) •ASCD: Operating
ON
• ASCD: Not operating OFF
Revision: April 20092010 QX56