2011 INFINITI QX56 sensor

TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-167
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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>> GO TO 26.
22.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal in air cleaner element
 Uneven dirt in air cleaner element
 Improper specification in intake air system
Is the inspection result normal?
YES >> GO TO 24.
NO >> Repair or replace malfunctioning part, and then GO TO 23.
23.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and check t hat the indication is within the SP
value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Less than the SP value: GO TO 24.
24.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and check that the indication is within the SP
value.
Is the measurement value within the SP value?
YES >> GO TO 25.
NO >> Less than the SP value: Replace malfunctioning mass air flow sensor, and then GO TO 27.
25.CHECK INTAKE SYSTEM
Check for the cause of air leakage after the mass air flow sensor. Refer to the following.
 Disconnection, looseness, and cracks in air duct
 Looseness of oil filler cap
 Disconnection of oil level gauge
 Open stuck, breakage, hose disconnection, or cracks in PCV valve
 Disconnection or cracks in EVAP purge hose, stuc k open EVAP canister purge volume control solenoid
valve
 Malfunctioning seal in rocker cover gasket
 Disconnection, looseness, or cracks in hoses, such as a vacuum hose, connecting to intake air system parts
 Malfunctioning seal in intake air system, etc.
>> GO TO 27.
26.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2” AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2” and “B/FUE L SCHDL” in “SPEC” of “DATA MONITOR” mode, and
check that each indication is within the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Detect malfunctioning part according to EC-524, "
Symptom Table".
27.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and then check that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Detect malfunctioning part according to EC-524, "
Symptom Table".
Revision: 2010 May2011 QX56

P0011, P0021 IVT CONTROLEC-177
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0011, P0021 IVT CONTROL
DTC LogicINFOID:0000000006217772
DTC DETECTION LOGIC
NOTE:
If DTC P0011 or P0021 is displayed with DTC P0075
or P0081, first perform the trouble diagnosis for
DTC P0075, P0081. Refer to EC-193, "
DTC 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-I
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Maintain the following conditions for at least 6 consecutive seconds. Hold the accelerator pedal as steady as possible.
4. Let engine idle for 25 seconds.
5. Check 1st trip DTC. WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-178, "Diagnosis Procedure"
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
WITH CONSULT-III
1. Select “DATA MONITOR” mode with CONSULT-III.
2. Maintain the following conditions for at least 20 consecutive seconds.
DTC No. Trouble diagnosis
(Trouble diagnosis con- tent) Detecting condition Possible cause
P0011 INT/V TIM CONT-B1
[Intake valve timing control
performance (bank 1)]
There is a gap between angle of target
and phase-control angle degree.  Crankshaft position sensor
 Camshaft position sensor
 Intake valve timing control solenoid valve
 Accumulation of debris to the signal pick-up
portion of the camshaft
 Timing chain installation
 Foreign matter caught in the oil groove for in- take valve timing control
P0021
INT/V TIM CONT-B2
[Intake valve timing control
performance (bank 2)]
ENG SPEED Less than 2,000 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70
°C (158 °F)
Selector lever P or N position
ENG SPEED 1,500 - 3,175 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Revision: 2010 May2011 QX56

EC-178
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0011, P0021 IVT CONTROL
CAUTION:
Always drive at a safe speed.
3. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-178, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217773
1.CHECK OIL PRESSURE WARNING LAMP
1. Start engine.
2. Check that oil pressure warning lamp is not illuminated.
Is oil pressure warning lamp illuminated?
YES >> Go to LU-7, "Inspection".
NO >> GO TO 2.
2.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE
Refer to EC-179, "
Component Inspection (Intake Valve Timing Control Solenoid Valve)".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EM-61, "
Exploded
View".
3.CHECK CRANKSHAFT POSITION SENSOR
Refer to EC-301, "
Component Inspection (Crankshaft Position Sensor)".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace crankshaft position sensor. Refer to EM-106, "
Exploded View".
4.CHECK CAMSHAFT POSITION SENSOR
Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace malfunctioning camshaft position sensor. Refer to EM-106, "
Exploded View".
5.CHECK CAMSHAFT (INTAKE)
Check the following.
Selector lever 1st or 2nd position
Driving location uphill Driving vehicle uphill
(Increased engine load will help maintain the driving
conditions required for this test.)
PBIA8559J
Revision: 2010 May2011 QX56

P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-181
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P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DTC LogicINFOID:0000000006217775
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 let it idle for at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-181, "Diagnosis Procedure".
NG >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217776
1.CHECK AIR FUEL RATIO (A/F) 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 3.
NO >> GO TO 2.
DTC No. Trouble diagnosis
(Trouble diagnosis content) DTC detecting condition Possible cause
P0031 A/F SEN1 HTR (B1)
[A/F sensor 1 heater (bank
1) control circuit low] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0032 A/F SEN1 HTR (B1)
[A/F sensor 1 heater (bank
1) control circuit high] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
P0051 A/F SEN1 HTR (B2)
[A/F sensor 1 heater (bank
2) control circuit low] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0052 A/F SEN1 HTR (B2)
[A/F sensor 1 heater (bank
2) control circuit high] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
DTC A/F sensor 1
Ground Voltage
Bank Connector Terminal
P0031, P0032 1 F67 5 Ground Battery voltage
P0051, P0052 2 F68 5
Revision: 2010 May2011 QX56

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

P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-183
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YES >> INSPECTION END
NO >> GO TO 2.
2.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 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).
>> INSPECTION END
2 and 3, 4, 6 ∞ Ω
(Continuity should not exist)
5 and 3, 4, 6 Terminal Resistance
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
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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