2011 INFINITI QX56 check engine

P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-181
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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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-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

P006A, P0101 MAF SENSOREC-187
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P006A, P0101 MAF SENSOR
DTC LogicINFOID:0000000006288269
DTC DETECTION LOGIC
NOTE:
If DTC P006A or P0101 is displayed with other DTC,
first perform the trouble diagnosis for other DTC.
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.
If engine will not start or stops soon, wait at leas t 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to normal operating temperature.
3. Accelerate the vehicle from 0 km/h (0 MPH) to 88 km/h (55 MPH) under the following conditions:
CAUTION:
Always drive at a safe speed.
NOTE:
 Accelerate with the accelerator pedal kept constant.
 The acceleration at engine speed 2,000 and 3,000 rpm allows easy diagnoses
4. Check 1st trip DTC. WITHOUT CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. With selector lever in D position, accelerate the vehicle from 0 km/h (0 MPH) to 88 km/h (55 MPH) under
the following conditions:
NOTE:
 Accelerate with the accelerator pedal kept constant.
 The acceleration at engine speed 2,000 and 3,000 rpm allows easy diagnoses.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P006A MAP-MAF CORELTION-B1
(Manifold pressure
- mass air
flow correlation) A difference exceeding the specified value develops
between a value transmitted from the manifold absolute
pressure sensor to ECM and an estimated intake pres-
sure of intake manifold calculated by ECM, based on a
mass sir flow sensor signal.  Harness or connectors
(The sensor circuit is open
or shorted.)
 Mass air flow sensor
 Manifold absolute pressure
sensor
 EVAP control system pres-
sure sensor
 Intake air leaks
 Intake air temperature sen- sor
P0101 MAF SEN/CIRCUIT-B1
(Mass air flow sensor circuit
range/performance) A difference exceeding the specified value develops
between a signal transmitted from the mass air flow
sensor to ECM.
Mass air flow sensor
ACCEL SEN 1 1.4 – 2.0 V
Selector lever D position
Revision: 2010 May2011 QX56

EC-190
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
Component Inspection (MAF Sensor)
INFOID:0000000006288271
1.CHECK MASS AIR FLOW SENSOR-I
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Connect CONSULT-III and select “DATA MONITOR” mode.
5. Select “MAS A/F SE-B1”, and check the indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Check the voltage between ECM harness connector terminals under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK FOR THE CAUSE OF UNEVEN AIR FL OW THROUGH MASS AIR FLOW SENSOR
1. Turn ignition switch OFF.
2. Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
- Crushed air ducts
- Malfunctioning seal of air cleaner element
- Uneven dirt of air cleaner element
- Improper specification of intake air system parts
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK MASS AIR FLOW SENSOR-II
WITH CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1””, and check the indication.
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
ECM Condition Voltage (V)
Connector +–
Terminal Terminal
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56

P006A, P0101 MAF SENSOREC-191
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Check the voltage between ECM harness connector terminals under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 4.
4.CHECK MASS AIR FLOW SENSOR-III
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor har ness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature.
4. Connect CONSULT-III and select “DATA MONITOR” mode.
5. Select “MAS A/F SE-B1” , and check the indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor har ness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature.
4. Check the voltage between ECM harness connector terminals under the following conditions.
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56

EC-192
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Clean or replace malfunctioning mass air flow sensor. Refer to
EM-27, "
Removal and Installation".
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56

P0075, P0081 IVT CONTROL SOLENOID VALVE
EC-193
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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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

P0087, P0088, P0090 FRP CONTROL SYSTEM
EC-195
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0087, P0088, P0090 FRP CONTROL SYSTEM
DTC LogicINFOID:0000000006217784
DTC DETECTION LOGIC
NOTE:

If DTC P0087 or P0090 is displayed with DTC P1197, first perform the trouble diagnosis for DTC
P1197.
 DTC P0087 or P0090 may be displayed when running out of gas.
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
1. Check that the fuel tank is 1/8 full of fuel.
2. Warm up the engine to the normal operating temperature and keep the engine speed at idle for 60 sec- onds.
NOTE:
Warm up the engine until “COOLAN TEMP/S” on “DATA MONITOR” of CONSULT-III reaches at least
70 °C (158 °F).
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-196, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Cool the engine until the engine coolant temperature reaches 60 °C (140 °F) or less.
2. Start the engine and wait at least 60 seconds.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-196, "Diagnosis Procedure".
NO >> INSPECTION END
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0087 High fuel pressure too low The following condition continues for 5
seconds or more after engine start (re-
gardless of water temperature): Target
fuel pressure
− Actual fuel pressure ≥
2.7 MPa (27 bar, 27.5 kg/cm
2, 392 psi)
 Harness or connectors(The fuel pump circuit is open or shorted.)
 Fuel system
P0088 high fuel pressure too high The following condition continues for 5
seconds or more after engine start (re-
gardless of water temperature):Actual
fuel pressure
− Target fuel pressure ≥
2.7 MPa (27 bar, 27.5 kg/cm
2, 392 psi)
P0090 High pressure fuel pump per-
formance Fuel rail pressure remains at 1.5 MPa
(15 bar, 15.3 kg/ cm
2, 217.5 psi) or less
for 3 seconds or more during engine rev.
Revision: 2010 May2011 QX56