2011 INFINITI QX56 sensor

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

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

P0102, P0103 MAF SENSOREC-201
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P0102, P0103 MAF SENSOR
DTC LogicINFOID:0000000006217789
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
Which DTC is detected?
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2.PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0102
1. Start engine and wait at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-201, "Diagnosis Procedure".
NO >> INSPECTION END
3.PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0103-I
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-201, "Diagnosis Procedure".
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P0103-II
1. Start engine and wait at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-201, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217790
1.INSPECTION START
Confirm the detected DTC.
Which DTC is detected?
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2.CHECK INTAKE SYSTEM
Check the following for connection.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0102 MAF SEN/CIRCUIT-B1
(Mass air flow sensor circuit
low input) An excessively low voltage from the sensor is
sent to ECM.  Harness or connectors
(The mass air flow sensor circuit is
open or shorted.)
 Intake air leakage
 Mass air flow sensor
P0103 MAF SEN/CIRCUIT-B1
(Mass air flow sensor circuit
high input) An excessively high voltage from the sensor is
sent to ECM.  Harness or connectors
(The mass air flow sensor circuit is
open or shorted.)
 Mass air flow sensor
Revision: 2010 May2011 QX56

EC-202
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0102, P0103 MAF SENSOR
 Air duct
 Vacuum hoses
 Intake air passage between air duct to intake manifold
Is the inspection result normal?
YES >> GO TO 3.
NO >> Reconnect the parts.
3.CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between MAF sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.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.
5.CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between MAF sens or 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 6.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between MAF sens or 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 7.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK MASS AIR FLOW SENSOR
Refer to EC-203, "
Component Inspection (MAF Sensor)".
Is the inspection result normal?
MAF sensor Ground Voltage
Connector Terminal
F31 5 Ground Battery voltage
MAF sensor ECM Continuity
Connector Terminal Connector Terminal
F 3 1 4 F 111 2 5 E x i s t e d
MAF 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

P0102, P0103 MAF SENSOREC-203
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YES >> GO TO 8.
NO >> Replace mass air flow sensor. Refer to
EM-27, "
Exploded View".
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (MAF Sensor)INFOID:0000000006290102
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.
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

EC-204
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0102, P0103 MAF SENSOR
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.
*: 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 harness 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 harness 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

P0102, P0103 MAF SENSOREC-205
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*: 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