2011 INFINITI QX56 air condition

P2A00, P2A03 A/F SENSOR 1EC-487
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2A00, P2A03 A/F SENSOR 1
DTC LogicINFOID:0000000006217987
DTC DETECTION LOGIC
To judge the malfunction, the A/F signal computed by ECM fr
om the A/F sensor 1 signal is monitored so it will
not shift to LEAN side or RICH side.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
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 1 minute under no load.
6. Let engine idle for 1 minute.
7. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
8. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-487, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217988
1.RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to EX-5, "
Exploded View".
>> GO TO 2.
2.CHECK A/F SENSOR 1 CONNECTOR
1. Disconnect A/F sensor 1 harness connector.
2. Check that water is not inside connectors.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harness connector.
3.CHECK FOR INTAKE AIR LEAKAGE
1. Reconnect A/F sensor 1 harness connector.
2. Start engine and run it at idle.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2A00 A/F SENSOR1 (B1)
(Air fuel ratio (A/F) sensor 1 (bank 1)
circuit range/performance)  The output voltage computed by ECM from
the A/F sensor 1 signal shifts to the lean side
for a specified period.
 The A/F signal computed by ECM from the
A/F sensor 1 signal shifts to the rich side for
a specified period.  A/F sensor 1
 A/F sensor 1 heater
 Fuel pressure
 Fuel injector
 Intake air leaks
P2A03 A/F SENSOR1 (B2)
(Air fuel ratio (A/F) sensor 1 (bank 2)
circuit range/performance)
Revision: 2010 May2011 QX56

EC-490
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCH
Component Function CheckINFOID:0000000006217989
1.CHECK ASCD BRAKE SWITCH FUNCTION
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 the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-490, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217990
1.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ASCD brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 3)
 Harness for open or short between ASCD brake switch and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit or short to ground in harness or connectors.
3.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ASCD brake s witch harness connector and ECM harness connector.
Monitor item Condition Indication
BRAKE SW1
(ASCD brake switch) Brake pedalSlightly depressed OFF
Fully released ON
ECM Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 147
(ASCD brake switch signal) 175 Brake pedalSlightly depressed Approx. 0
Fully released Battery voltage
ASCD brake switch
Ground Voltage
Connector Terminal
E109 1 Ground Battery voltage
Revision: 2010 May2011 QX56

ASCD BRAKE SWITCHEC-491
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and ASCD brake switch
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK ASCD BRAKE SWITCH
Refer to EC-491, "
Component Inspection (ASCD Brake Switch)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace ASCD brake switch. Refer to BR-20, "
Removal and Installation".
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (ASCD Brake Switch)INFOID:0000000006217991
1.CHECK ASCD BRAKE SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check the continuity between ASCD brake swit ch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK ASCD BRAKE SWITCH-II
1. Adjust ASCD brake switch installation. Refer to BR-21, "
Inspection and Adjustment".
2. Check the continuity between ASCD brake swit ch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ASCD brake switch. Refer to BR-20, "
Removal and Installation".
ASCD brake switch ECM
Continuity
Connector Terminal Connector Terminal
E109 2 E80 147 Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Revision: 2010 May2011 QX56

EC-492
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ASCD INDICATOR
ASCD INDICATOR
Component Function CheckINFOID:0000000006217992
1.CHECK ASCD INDICATOR FUNCTION
Check ASCD indicator under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-492, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217993
1.CHECK DTC
Check that DTC UXXXX is not displayed.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform trouble diagnosis for DTC UXXXX.
2.CHECK DTC WITH COMBINATION METER
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace malfunctioning part.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace combination meter. Refer to MWI-85, "Removal and Installation".
NO >> Repair or replace malfunctioning part.
ASCD INDICATOR CONDITION SPECIFICATION
CRUISE LAMP  Ignition switch: ON  MAIN switch: Pressed at the
1st time →
at the 2nd time ON
→ OFF
Revision: 2010 May2011 QX56

EC-502
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
HIGH PRESSURE FUEL PUMP
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK HIGH PRESSURE
FUEL PUMP SOLENOID
Refer to EC-502, "
Component Inspection".
Is inspection result normal?
YES >> GO TO 3.
NO >> Replace high pressure fuel pump. Refer to EM-43, "
Removal and Installation".
3.CHECK HIGH PRESSURE FUEL PUMP INSTALLATION CONDITION
1. Turn ignition switch OFF.
2. Check that the high pressure fuel pump is installed with no backlash and looseness.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK CAMSHAFT
1. Remove camshaft. Refer to EM-75, "
Removal and Installation".
2. Check camshaft. Refer to EM-77, "
Inspection".
Is inspection result normal?
YES >> INSPECTION END
NO >> Replace camshaft. Refer to EM-75, "
Removal and Installation".
Component InspectionINFOID:0000000006218007
1.CHECK HIGH PRESSURE FUEL PUMP SOLENOID
1. Turn ignition switch OFF.
2. Disconnect high pressure fuel pump harness connector.
3. Check the resistance between high pressure fuel pump connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace high pressure fuel pump. Refer to EM-43, "
Removal and Installation".
+−
Condition Resistance
High pressure fuel pump
Te r m i n a l
1 2 Temperature 20 – 30 °C (68 – 86 °F) 9 – 11 Ω
Revision: 2010 May2011 QX56

EC-504
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ICC BRAKE SWITCH
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 3.
3.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ICC brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 4.
4.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II
Check the voltage between ICC brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Fuse block (J/B) connector E103
 10 A fuse (No. 3)
 Harness for open or short between ICC brake switch and fuse
>> Repair open circuit or short to ground in harness or connectors.
6.CHECK ICC BRAKE SWITCH
Refer to EC-445, "
Component Inspection (ICC Brake Switch)".
Is the inspection result normal?
YES >> GO TO 9.
NO >> Replace ICC brake switch. Refer to BR-20, "
Removal and Installation".
7.CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ICC brake s witch harness connector and ECM harness connector.
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 147
(ICC brake switch signal) 175 Brake pedalSlightly depressed Approx. 0
Fully released Battery voltage
ICC brake switch
Ground Voltage
Connector Terminal
E68 2 Ground Battery voltage
ICC brake switch Ground Voltage
Connector Terminal
E68 1 Ground Battery voltage
Revision: 2010 May2011 QX56

ICC BRAKE SWITCHEC-505
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ICC brake switch and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
9.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (ICC Brake Switch)INFOID:0000000006218010
1.CHECK ICC BRAKE SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check the continuity between ICC brake switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK ICC BRAKE SWITCH-II
1. Adjust ICC brake switch installation. Refer to BR-21, "
Inspection and Adjustment".
2. Check the continuity between ICC brake switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ICC brake switch. Refer to BR-20, "
Removal and Installation".
ICC brake switch ECM
Continuity
Connector Terminal Connector Terminal
E68 2 E80 147 Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Revision: 2010 May2011 QX56

LOW PRESSURE FUEL PUMPEC-513
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK FUEL PUMP CONTROL CIRCUIT
1. Disconnect fuel level sensor unit and fuel pump harness connector.
2. Check the continuity between FPCM harness connecto r and fuel level sensor unit and fuel pump harness
connector.
3. Also check harness for short to ground and to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK LOW PRESSURE FUEL PUMP
Refer to EC-513, "
Component Inspection (Low Pressure Fuel Pump)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-5, "
Removal and Installation".
6.CHECK FPCM
Refer to EC-514, "
Component Inspection (FPCM)".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace FPCM. Refer to EC-537, "
Removal and Installation".
Component Inspection (Low Pressure Fuel Pump)INFOID:0000000006218019
1.CHECK FUEL PRESSURE REGULATOR
1. Turn ignition switch OFF.
2. Check low fuel pressure. Refer to EC-153, "
Work Procedure".
Is inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK LOW PRESSURE FUEL PUMP
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump.
3. Check resistance between fuel level sens or unit and fuel pump terminals as follows.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-5, "
Removal and Installation".
+−
Continuity
FPCM Fuel level sensor unit and fuel pump
Connector Terminal Connector Terminal
B41 6
C5 3
Existed
71
+ −
Condition Resistance
Fuel level sensor unit and fuel
pump
Te r m i n a l s
1 3 Temperature: 25 °C (77 °F) 0.2 - 5.0 Ω
Revision: 2010 May2011 QX56