sensor INFINITI QX56 2011 Factory Service Manual

EC-486
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
Is the inspection result normal?
YES >> INSPECTION END.
NO >> Replace low fuel pressure sensor. Refer to EM-43, "
Removal and Installation".
+−
Condition Va l u e
(Approx.)
Low fuel pressure sensor
Ground
Connector Terminal
F25 2 Ground [Engine is running]
 Warm-up condition
 Idle speed
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm
JPBIA3357ZZ
JPBIA3358ZZ
Revision: 2010 May2011 QX56

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-488
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2A00, P2A03 A/F SENSOR 1
3. Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 4.
4.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P 0175 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-264, "Diagnosis
Procedure" or EC-268, "Diagnosis Procedure".
NO >> GO TO 5.
5.CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between A/F sensor 1 harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK A/F SENSOR 1 INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector
and ground.
5. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK A/F SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
DTCA/F sensor 1
Ground Voltage
Bank Connector Terminal
P2A00 1 F67 4 Ground 3.0 V
P2A03 2 F68 4
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P2A00 1 F67 3 F11088
Existed
P2A03 2 F68 3 78
DTC A/F sensor 1 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P2A00 1 F67 3 F11088
Ground Not existed
P2A03 2 F68 3 78
Revision: 2010 May2011 QX56

P2A00, P2A03 A/F SENSOR 1EC-489
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
8.CHECK A/F SENSOR 1 HEATER
Refer to EC-182, "
Component Inspection (A/F Sensor 1 Heater)".
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 10.
9.CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 10.
NO >> Repair or replace malfunctioning part.
10.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1. Refer to EX-5, "
Exploded View".
CAUTION:
 Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
 Before installing new A/F senso r, clean exhaust system threads using Oxygen Sensor Thread
Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).
Will CONSULT-III be used?
YES >> GO TO 11.
NO >> GO TO 12.
11 .CONFIRM A/F ADJUSTMENT DATA
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-III.
3. Check that “0.000” is di splayed on CONSULT-III screen.
Is
“0.000” displayed?
YES >> INSPECTION END
NO >> GO TO 12.
12.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
Will CONSULT-III be used?
YES >> GO TO 13.
NO >> INSPECTION END
13.CONFIRM A/F ADJUSTMENT DATA
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-III.
3. Check that “0.000” is di splayed on CONSULT-III screen.
>> INSPECTION END
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P2A00 1 F67 6 F11094
Existed
P2A03 2 F68 6 74
Revision: 2010 May2011 QX56

ELECTRICALLY-CONTROLLED COOLING FAN COUPLINGEC-497
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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NO >> Repair or replace error-detected parts.
6.CHECK CAN COMMUNICATION
Refer to LAN-18, "
Trouble Diagnosis Flow Chart".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or Replace error-detected parts.
7.CHECK COOLING FAN SPEED SENSOR
Refer to EC-367, "
Diagnosis Procedure".
Is inspection result normal?
YES >> Replace electrically-controlled cooling fan coupling. Refer to CO-16, "Removal and Installation".
NO >> Repair or replace error-detected parts.
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

EC-516
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
ON BOARD REFUELING VA
POR RECOVERY (ORVR)
Component Function CheckINFOID:0000000006256490
1.CHECK ORVR FUNCTION
Check whether the following symptoms are present.
 Fuel odor from EVAP canister is strong.
 Cannot refuel/Fuel odor from the fuel filler opening is strong while refueling.
Are any symptoms present?
YES >> Proceed to EC-516, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256491
1.INSPECTION START
Check whether the following symptoms are present.
A: Fuel odor from EVAP canister is strong.
B: Cannot refuel/Fuel odor from the fuel filler opening is strong while refueling.
Which symptom is present?
A>>GO TO 2.
B>>GO TO 7.
2.CHECK EVAP CANISTER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Weigh the EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be l ess than 2.5 kg (5.5 lb).
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK IF EVAP CANISTER IS SATURATED WITH WATER
Check if water will drain from EVAP canister (1).
 EVAP canister vent control valve (2)
Does water drain from the EVAP canister?
YES >> GO TO 4.
NO >> GO TO 6.
4.REPLACE EVAP CANISTER
Replace EVAP canister with a new one.
>> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the EVAP hose between EVAP canister and vehicle frame for clogging or poor connection.
>> Repair or replace EVAP hose.
6.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-518, "
Component Inspection (EVAP Vapor Cut Valve)".
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Revision: 2010 May2011 QX56

ON BOARD REFUELING VAPOR RECOVERY (ORVR)EC-517
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace refueling EVAP vapor cut valve with fuel tank.
7.CHECK EVAP CANISTER
1. Remove EVAP canister with EVAP canister vent c ontrol valve and EVAP control system pressure sensor
attached.
2. Weigh the EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be l ess than 2.5 kg (5.5 lb).
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 9.
8.CHECK IF EVAP CANISTER IS SATURATED WITH WATER
Check if water will drain from EVAP canister (1).
 EVAP canister vent control valve (2)
Does water drain from the EVAP canister?
YES >> GO TO 9.
NO >> GO TO 11.
9.REPLACE EVAP CANISTER
Replace EVAP canister with a new one.
>> GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the EVAP hose between EVAP canister and vehicle frame for clogging or poor connection.
>> Repair or replace EVAP hose.
11 .CHECK VENT HOSES AND VENT TUBES
Check hoses and tubes between EVAP c anister and refueling control valve for clogging, kinks, looseness and
improper connection.
Is the inspection result normal?
YES >> GO TO 12.
NO >> Repair or replace hoses and tubes.
12.CHECK FILLER NECK TUBE
Check recirculation line for clogging, dents and cracks.
Is the inspection result normal?
YES >> GO TO 13.
NO >> Replace filler neck tube.
13.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-518, "
Component Inspection (EVAP Vapor Cut Valve)".
Is the inspection result normal?
YES >> GO TO 14.
NO >> Replace refueling EVAP vapor cut valve with fuel tank.
14.CHECK FUEL FILLER TUBE
Check filler neck tube and hose connected to the fuel tank for clogging, dents and cracks.
JSBIA0692ZZ
Revision: 2010 May2011 QX56

EC-520
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Component Function CheckINFOID:0000000006218026
1.CHECK REFRIGERANT PRESSURE SENSOR FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-520, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218027
1.CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressu re sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between refrigerant pressure sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and refrigerant pressure sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between refrigerant pre ssure sensor harness connector and ECM harness connec-
tor.
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.
ECM Voltage (V)
Connector +–
Terminal Terminal
E80 144
(Refrigerant pressure sensor signal) 150 1.0 - 4.0
Refrigerant pressure sensor
Ground Voltage (V)
Connector Terminal
E77 1 Ground Approx. 5
Refrigerant pressure sensor ECM Continuity
Connector Terminal Connector Terminal
E77 3 E80 150 Existed
Revision: 2010 May2011 QX56

REFRIGERANT PRESSURE SENSOREC-521
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and refrigerant pressure sensor
 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 REFRIGERANT PRESSURE SENSOR IN PUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between refrigerant pre ssure sensor harness connector and ECM harness connec-
tor.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and refrigerant pressure sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace refrigerant pressure sensor. Refer to HA-39, "REFRIGERANT PRESSURE SENSOR :
Removal and Installation".
NO >> Repair or replace malfunctioning part.
Refrigerant pressure sensor ECM Continuity
Connector Terminal Connector Terminal
E77 2 E80 144 Existed
Revision: 2010 May2011 QX56