2011 INFINITI QX56 ground

EC-182
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0031, P0032, P0051, P00
52 A/F SENSOR 1 HEATER
2.DETECT MALFUNCTIONING PART
Check the following.
 20 A fuse (No. 43)
 Harness for open or short between A/F sensor 1 and fuse
 Loose or poor connection for each connector and harness
>> Repair or replace harness or connectors.
3.CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL 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. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.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 6.
NO >> GO TO 5.
5.REPLACE A/F SENSOR 1
Replace malfunctioning A/F sensor 1. Refer to EM-40, "
Exploded View".
CAUTION:
 Discard any A/F sensor which has b een 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 sensor, clean exhau st 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).
>> INSPECTION END
6.CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (A/F Sensor 1 Heater)INFOID:0000000006217777
1.CHECK AIR FUEL RATIO (A/F) SENSOR 1
1. Turn ignition switch OFF.
2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
3. Check resistance between A/F sensor 1 terminals as per the following.
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0031, P0032 1 F67 2 F11048
Existed
P0051, P0052 2 F68 2 53
Terminal Resistance
2 and 5 2.0 - 3.2 Ω [at 25 °C (77 °F)]
Revision: 2010 May2011 QX56

EC-184
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0037, P0038, P0057,
P0058 HO2S2 HEATER
P0037, P0038, P0057, P0058 HO2S2 HEATER
DTC LogicINFOID:0000000006217778
DTC DETECTION LOGIC
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. Start engine and warm it up to the normal operating temperature.
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 at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-184, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217779
1.CHECK HEATED OXYGEN SENSOR 2 (HO2S2) POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
2. Turn ignition switch ON.
3. Check the voltage between HO2S2 harness connector and ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0037 HO2S2 HTR (B1)
[Heated oxygen sensor 2
heater (bank 1) control cir-
cuit low] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
 Heated oxygen sensor 2 heater
P0038 HO2S2 HTR (B1)
[Heated oxygen sensor 2
heater (bank 1) control cir-
cuit high] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
 Heated oxygen sensor 2 heater
P0057 HO2S2 HTR (B2)
[Heated oxygen sensor 2
heater (bank 2) control cir-
cuit low] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
 Heated oxygen sensor 2 heater
P0058 HO2S2 HTR (B2)
[Heated oxygen sensor 2
heater (bank 2) control cir-
cuit high] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
 Heated oxygen sensor 2 heater
Revision: 2010 May2011 QX56

P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-185
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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EC
NP
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Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 20 A fuse (No. 43)
 Harness for open or short between heated oxygen sensor 2 and fuse
 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 HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between HO2S2 harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK HO2S2 HEATER
Refer to EC-186, "
Component Inspection (HO2 Sensor 2 Heater)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to EX-5, "
Removal and Installation".
CAUTION:
 Discard any heated oxygen sensor which has been dr opped 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 oxygen sensor, clean exh aust 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).
>> INSPECTION END
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC HO2S2
Ground Voltage
Bank Connector Terminal
P0037, P0038 1 F87 2 Ground Battery voltage
P0057, P0058 2 F88 2
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0037, P0038 1 F87 3 F 11147
Existed
P0057, P0058 2 F88 3 52
Revision: 2010 May2011 QX56

EC-188
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
CAUTION:
Always drive at a safe speed.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-188, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288270
1.CHECK INTAKE SYSTEM
Check the following for connection.
 Air duct
 Vacuum hoses
 Intake air passage between air duct and intake manifold
Is the inspection result normal?
YES >> GO TO 2.
NO >> Reconnect the parts.
2.CHECK MASS AIR FLOW SENS OR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between mass air flow sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between mass air flow sensor and ECM
 Harness for open or short between mass air flow sensor and IPDM E/R
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK MASS AIR FLOW SENSOR GR OUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between mass air flow sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Accelerator pedal position sensor 1 Ground Voltage (V)
Connector Terminal
E110 (Whthout ICC) 3 Ground 1.4 – 2.0
E67 (With ICC) 10
Mass air flow sensor Ground Voltage
Connector Terminal
F31 5 Ground Battery volt-
age
Mass air flow sensor ECM Continu-
ity
Connec-
tor Te r m i n a l Connec-
tor Te r m i n a l
F 3 1 4 F 111 2 5 E x i s t e d
Revision: 2010 May2011 QX56

P006A, P0101 MAF SENSOREC-189
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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EC
NP
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Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK MASS AIR FLOW SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between mass air flow sensor harness connector and ECM harness connector.
2. Also check harness for short to ground and short to power.
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 MANIFOLD ABSO LUTE PRESSURE SENSOR
Check manifold absolute pressure sensor. Refer to EC-208, "
Component Inspection (MAP Sensor)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace manifold absolute pressure sensor. Refer to EM-30, "
Removal and Installation".
7.CHECK INTAKE AIR TEMPERATURE SENSOR
Check intake air temperature sensor. Refer to EC-225, "
Component Inspection (Intake Air Temperature Sen-
sor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace mass air flow sensor (with intake air temperature sensor). Refer to EM-27, "
Removal and
Installation".
8.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-335, "
Component Inspection (EVAP Control System Pressure Sensor)".
Is the inspection result normal?
YES-1 (Only DTC P006A is detected)>>GO TO 9.
YES-2 (DTC P006A and P0101 are detected)>>GO TO 10.
NO >> Replace EVAP control system pressure sensor. Refer to FL-12, "
Removal and Installation".
9.CHECK MASS AIR FLOW SENSOR
Refer to EC-190, "
Component Inspection (MAF Sensor)".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Replace mass air flow sensor.
10.CHECK MASS AIR FLOW SENSOR
Check mass air flow sensor. Refer to EC-190, "
Component Inspection (MAF Sensor)".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Replace mass air flow sensor. Refer to EM-27, "
Removal and Installation".
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Mass air flow sensor ECM Continuity
Connector Terminal Connector Terminal
F 3 1 3 F 111 2 2 E x i s t e d
Revision: 2010 May2011 QX56

P0075, P0081 IVT CONTROL SOLENOID VALVE
EC-193
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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EC
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P0075, P0081 IVT CONTRO
L SOLENOID VALVE
DTC LogicINFOID:0000000006217781
DTC DETECTION LOGIC
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-193, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217782
1.CHECK INTAKE VALVE TIMING CONTROL SO LENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect intake valve timing (IVT) control solenoid valve harness connector.
3. Turn ignition switch ON.
4. Check the voltage between IVT control solenoid valve 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 IVT control solenoid valve and IPDM E/R
 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 IVT CONTROL SOLENOID VALVE OUTP UT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0075 INT/V TIM V/CIR-B1
[Intake valve timing control sole-
noid valve (bank 1) circuit]
An improper voltage is sent to the ECM
through intake valve timing control solenoid
valve.  Harness or connectors
(Intake valve timing control solenoid
valve circuit is open or shorted.)
 Intake valve timing control solenoid valve
P0081 INT/V TIM V/CIR-B2
[Intake valve timing control sole-
noid valve (bank 2) circuit]
DTC
IVT control solenoid valve
Ground Voltage
Bank Connector Terminal
P0075 1 F47 2 Ground Battery voltage
P0081 2 F61 2
Revision: 2010 May2011 QX56

EC-194
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0075, P0081 IVT CONTROL SOLENOID VALVE
2. Disconnect ECM harness connector.
3. Check the continuity between IVT control sol
enoid valve harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK IVT CONTROL SOLENOID VALVE
Refer to EC-194, "
Component Inspection (Intake Valve Timing Control Solenoid Valve)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace malfunctioning IVT control solenoid valve. Refer to EM-61, "
Exploded View".
5.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Intake Valv e Timing Control Solenoid Valve)INFOID:0000000006288359
1.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE-I
1. Turn ignition switch OFF.
2. Disconnect intake valve timing control solenoid valve harness connector.
3. Check resistance between intake valve timing control solenoid valve terminals as per the following.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EM-61, "
Exploded
View".
2.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE-II
1. Remove intake valve timing control solenoid valve.
2. Provide 12 V DC between intake valve timing control solenoid valve terminals 1 and 2, and then interrupt it. Check that the
plunger moves as shown in the figure.
CAUTION:
Never apply 12 V DC continuously for 5 seconds or more.
Doing so may result in damage to the coil in intake valve
timing control solenoid valve.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EM-61, "
Exploded
View".
DTCIVT control solenoid valve ECM
Continuity
Bank Connector Terminal Connector Terminal
P0075 1 F47 1 F 11149
Existed
P0081 2 F61 1 54
Terminals Resistance
1 and 2 7.0 - 7.7 Ω [at 20 °C (68 °F)]
1 or 2 and ground ∞
Ω
(Continuity should not exist)
JMBIA0079ZZ
Revision: 2010 May2011 QX56

EC-196
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0087, P0088, P009
0 FRP CONTROL SYSTEM
Diagnosis Procedure
INFOID:0000000006217785
1.CHECK LOW FUEL PRESSURE
WITH CONSULT-III
1. Start the engine.
2. Check “L/FUEL PRES SEN V” in “DAT A MONITOR” of “ECM” with CONSULT-III.
WITHOUT CONSULT-III
1. Start the engine.
2. Check low fuel pressure sensor signal voltage.
Is inspection result normal?
YES >> GO TO 2.
NO >> Check low fuel pressure system. Refer to EC-512, "
Diagnosis Procedure".
2.PERFORM THE HIGH PRESSURE FUEL PUMP COMPONENT INSPECTION
Perform the high pressure fuel pum p component inspection. Refer to EC-196, "
Component Inspection".
Is inspection result normal?
YES >> GO TO 3.
NO >> Replace the fuel pump.
3.CHECK FUEL LEAKAGE
1. Start the engine.
2. Visually check that the fuel pump, fuel rail, and fuel piping have no fuel leakage.
Is inspection result normal?
YES >> Check that the fuel syst em has no breakage, bend, and crush.
NO >> Repair or Replace the error-detected parts.
Component InspectionINFOID:0000000006217786
1.CHECK HIGH PRESSURE FUEL PUMP-I
1. Turn ignition switch OFF.
2. Disconnect high pressure fuel pump harness connector.
3. Check the resistance between high pressure fuel pump terminals as follows.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace high pressure fuel pump. Refer to EM-49, "
Removal and Installation".
Data monitor item Condition Va l u e
(Approx.)
L/FUEL PRES SEN V Engine speed: idle
3,000 –3,300 mV
Engine speed: 3,000 rpm (no load)
+ −Condition Va l u e
(Approx.)
Low fuel pressure sensor
Connector Terminal
F25 2 Ground Engine speed: idle
3.0 –3.3 V
Engine speed: 3,000 rpm (no load)
+ −
Condition Resistance
High pressure fuel pump
Te r m i n a l
1 2 Temperature °C ( °F) 20 – 30 (68 - 86) 9 - 11 Ω
Revision: 2010 May2011 QX56