2011 INFINITI QX56 Fuel

P0087, P0088, P0090 FRP CONTROL SYSTEM
EC-197
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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2.CHECK HIGH PRESSURE FUEL PUMP-II
WITH CONSULT-III
1. Reconnect high pressure fuel pump harness connector.
2. Start the engine.
3. Check “FUEL PRES SEN” in “DATA MONITOR” of “ECM” with CONSULT-III.
WITHOUT CONSULT-III
1. Start the engine.
2. Check fuel rail pressure sensor signal voltage.
YES >> INSPECTION END
NO >> Replace high pressure fuel pump. Refer to EM-43, "
Removal and Installation".
Data monitor item Condition Vo l ta g e
(Approx.)
FUEL PRES SEN V Engine speed: idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm quickly 1,100 – 2,900 mV
+ − Condition Va l u e
(Approx.)
Fuel rail pressure sensor
Connector Terminal
F26 2 Ground Engine speed: idle 0.98 – 1.2 V
Engine speed: Revving engine from idle to 4,000 rpm quickly 1.1 – 2.9 V
Revision: 2010 May2011 QX56

EC-198
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P008A LOW FUEL PRESSURE CONTROL SYSTEM
P008A LOW FUEL PRESSURE CONTROL SYSTEM
DTC LogicINFOID:0000000006217787
DTC DETECTION LOGIC
NOTE:
If DTC P008A is displayed with DTC P1197, first pe
rform the trouble diagnosis for DTC P1197. Refer to
EC-397, "
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
1. Check that the fuel tank is 1/8 full of fuel.
2. Start the engine and warm it up to the normal operating temperature. NOTE:
When replacing ECM, warm up the engine until “C OOLAN TEMP/S” on “DATA MONITOR” of CONSULT-
III reaches at least 70 °C (158 °F).
3. Let the engine at idle for 60 seconds.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-398, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217788
1.PERFORM LOW PRESSURE FUEL PUMP COMPONENT FUNCTION CHECK
Refer to EC-512, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform low pressure fuel pump diagnosis. Refer to EC-512, "
Diagnosis Procedure".
2.CHECK FUEL LEAKAGE
1. Start the engine.
2. Visually check that the low fuel pressure system has no fuel leakage.
Is inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK LOW PRESSURE FUEL PIPING AND HOSE
1. Turn ignition switch OFF.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P008A Low fuel pressure too low A condition of low fuel pressure 0.23
MPa (2.3 bar, 2.346 kg/cm
2, 33.35 psi)
or less continues for 5 seconds or more
after warming up the engine.  Harness or connectors
(The low pressure fuel pump circuit is
open or shorted.)
 Low pressure fuel pump
 Fuel pressure regulator
 Low pressure fuel system
 Out of gas
Revision: 2010 May2011 QX56

P008A LOW FUEL PRESSURE CONTROL SYSTEMEC-199
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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2. Check that the low pressure fuel piping and hose have no breakage, bend, and crush. Refer to
FL-4,
"Inspection".
Is inspection result normal?
YES >> Replace fuel level sensor unit and fuel pump (fuel pressure regulator malfunction). Refer to FL-5,
"Removal and Installation".
NO >> Repair or replace error-detected parts.
Revision: 2010 May2011 QX56

EC-200
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P008B LOW FUEL PRESSURE CONTROL SYSTEM
P008B LOW FUEL PRESSURE CONTROL SYSTEM
DTC LogicINFOID:0000000006288272
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
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 the engine and keep the engine speed at idle for 60 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-200, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288273
1.CHECK FUEL PUMP CONTROL MODULE (FPCM) SIGNAL
Refer to EC-405, "
Component Inspection (FPCM)".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace FPCM. Refer to EC-537, "
Removal and Installation".
2.CHECK FUEL PUMP CONTROL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect FPCM harness connector and fuel level sensor unit and fuel pump harness connector.
3. Check the continuity between FPCM harness connecto r and fuel level sensor unit and fuel pump harness
connector.
4. Also check harness for short to ground and short to power.
Is inspection result normal?
YES >> Replace fuel level sensor unit and fuel pump (fuel pressure regulator malfunction). Refer to FL-5,
"Removal and Installation".
NO >> Repair or replace error-detected parts.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P008B Low fuel pressure too high A condition of low fuel pressure 0.67
MPa (6.7 bar, 6.834 kg/cm
2, 97.15 psi)
or more continues for 5 seconds or
more after warming up the engine.  Harness or connectors
(The low pressure fuel pump circuit is
open or shorted.)
 Fuel pressure regulator
FPCM Fuel level sensor unit and fuel pump Continuity
Connector Terminal Connector Terminal
B41 6
C5 3
Existed
71
Revision: 2010 May2011 QX56

P0116 ECT SENSOREC-215
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0116 ECT SENSOR
DTC LogicINFOID:0000000006288277
DTC DETECTION LOGIC
NOTE:
If DTC P0116 is displayed with P0117 or P0118,
first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-217, "
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.
TEST CONDITION:
Before performing the following procedure, do not add fuel.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than 10 minutes.
3. Move the vehicle to a cool place, then stop engine.
4. Check resistance between “fuel level s ensor unit and fuel pump” terminals 4 and 5.
5. Soak the vehicle until the resistance between “fuel level sensor unit and fuel pump” terminals 4 and 5
becomes 0.5 k Ω higher than the value measured before soaking.
CAUTION:
Never turn ignition sw itch ON during soaking.
NOTE:
Soak time changes depending on ambient ai r temperature. It may take several hours.
6. Start engine and let it idle for 20 minutes.
7. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-215, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288278
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-216, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor. Refer to EM-86, "
Exploded View".
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0116 ECT SEN/CIRC
(Engine coolant tempera-
ture sensor circuit range/
performance) Engine coolant temperature signal from engine
coolant temperature sensor does not fluctuate,
even when some time has passed after starting
the engine with pre-warming up condition.
 Harness or connectors
(High or low resistance in the circuit)
 Engine coolant temperature sensor
Revision: 2010 May2011 QX56

EC-222
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0125 ECT SENSOR
P0125 ECT SENSOR
DTC LogicINFOID:0000000006288280
DTC DETECTION LOGIC
NOTE:
If DTC P0125 is displayed with P0117 or P0118,
first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-217, "
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.
>> GO TO 2.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the temperature above 10
°C (50°F)?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and run it for 65 minutes at idle speed. If “COOLAN TEMP/S” increases to more than 10 °C (50 °F) within 65 minutes, stop engine because
the test result will be OK.
CAUTION:
Never overheat engine.
2. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> EC-222, "Diagnosis Procedure"
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288281
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-218, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0125 ECT SENSOR
(Insufficient engine coolant
temperature for closed loop
fuel control)  Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
 Engine coolant temperature is insufficient for closed loop fuel control.  Harness or connectors
(High resistance in the circuit)
 Engine coolant temperature sensor
 Thermostat
Revision: 2010 May2011 QX56

EC-226
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0128 THERMOSTAT FUNCTION
P0128 THERMOSTAT FUNCTION
DTC LogicINFOID:0000000006288286
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301,
P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to EC-291, "
DTC Logic".
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leakage in the seal or the thermostat being stuck open.
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:
 For best results, perform at ambient temperature of –10 °C (14 °F) or higher.
 For best results, perform at en gine coolant temperature of –10 °C (14 °F) to 52 °C (126 °F).
 Before performing the following procedure, do not add fuel.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”. If it is below 52 °C (126 °F), go to next step.
If it is above 52 °C (126 °F), cool engine down to less than 52 °C (126 °F). Then go to next step.
6. Start engine and drive vehicle for 10 consec utive minutes under the following conditions.
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “COOLAN TEMP/S” increases to more than 71 °C (160 °F) within 10 minutes, turn ignition switch
OFF because the test result will be OK.
7. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-227, "Diagnosis Procedure".
NO >> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0128 THERMSTAT FNCTN
(Thermostat function) The engine coolant temperature does not
reach to specified temperature even
though the engine has run long enough. Thermostat
 Leakage from sealing portion of thermostat
 Engine coolant temperature sensor
Vehicle speed More than 56 km/h (35 MPH)
Revision: 2010 May2011 QX56

EC-228
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0130, P0150 A/F SENSOR 1
P0130, P0150 A/F SENSOR 1
DTC LogicINFOID:0000000006217804
DTC DETECTION LOGIC
To judge malfunctions, the diagnosis checks that the A/
F signal computed by ECM from the A/F sensor 1 sig-
nal fluctuates according to fuel feedback control.
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 FOR MALFUNCTION A
1. Start engine and warm it up to normal operating temperature.
2. Let engine idle for 2 minutes.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-230, "Diagnosis Procedure".
NO-1 >> With CONSULT-III: GO TO 3.
NO-2 >> With GST: GO TO 7.
3.CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B 2)” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
Does the indication fluctuate around 1.5 V?
YES >> GO TO 4.
NO >> Go to EC-230, "
Diagnosis Procedure".
4.PERFORM DTC CONFIRMATION PR OCEDURE FOR MALFUNCTION B-I
1. Select “A/F SEN1 (B1) P1276” (for DTC P0130) or “A/F SEN1 (B2) P1286” (for DTC P0150) of “A/F
SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
2. Touch “START”.
3. When the following conditions are met, “T ESTING” will be displayed on the CONSULT-III screen.
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible Cause
P0130 A/F SENSOR1 (B1)
[Air fuel ratio (A/F) sensor 1
(bank 1) circuit] A)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in a range other
than approx. 1.5 V.
 Harness or connectors(The A/F sensor 1 circuit is open
or shorted.)
 A/F sensor 1
B)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 1.5 V.
P0150 A/F SENSOR1 (B2)
[Air fuel ratio (A/F) sensor 1
(bank 2) circuit] A)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in a range other
than approx. 1.5 V.
B) The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 1.5 V.
Revision: 2010 May2011 QX56