Fuel INFINITI QX56 2011 Factory Service Manual

EC-272
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0181 FTT SENSOR
NO >> Proceed to
MWI-69, "Component Function Check".
2.CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor uni t and fuel pump” harness connector.
3. Turn ignition switch ON.
4. Check the voltage between “fuel level sensor unit and fuel pump” 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 ECM and “fuel level sensor unit and fuel pump”
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connector.
4.CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “combination meter” harness connector.
3. Check the continuity between “fuel level sensor unit and fuel pump” harness connector and “combination
meter” harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between “fuel level s ensor unit and fuel pump” and “combination meter”
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connector.
6.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-273, "
Component Inspection (Fuel Tank Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-5, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Fuel level sensor unit and fuel pump Ground Voltage (V)
Connector Terminal
C5 4 Ground Approx. 5
Fuel level sensor unit and fuel pump Combination meter
Continuity
Connector Terminal Connector Terminal
C5 5 M34 24 Existed
Revision: 2010 May2011 QX56

P0181 FTT SENSOREC-273
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Component Inspection (Fuel
Tank Temperature Sensor)INFOID:0000000006288291
1.CHECK FUEL TANK TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness connector.
3. Remove fuel level sensor unit.
4. Check resistance between “fuel level sensor unit and fuel pump ” terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace “fuel level sensor unit and fuel pump”.
Terminals Condition Resistance (k Ω)
4 and 5 Temperature [ °C ( °F)] 20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
JMBIA0167ZZ
Revision: 2010 May2011 QX56

EC-274
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0182, P0183 FTT SENSOR
P0182, P0183 FTT SENSOR
DTC LogicINFOID:0000000006288292
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. Turn ignition switch ON and wait at least 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-274, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288293
1.CHECK DTC WITH COMBINATION METER
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Proceed to MWI-69, "
Component Function Check".
2.CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor uni t and fuel pump” harness connector.
3. Turn ignition switch ON.
4. Check the voltage between “fuel level sensor unit and fuel pump” 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 ECM and “fuel level sensor unit and fuel pump”
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0182 FTT SEN/CIRCUIT
(Fuel tank temperature sen-
sor circuit low input) An excessively low voltage from the sensor is
sent to ECM.
 Harness or connectors
(The FTT sensor circuit is open or
shorted.)
 Fuel tank temperature sensor
 Combination meter
P0183 FTT SEN/CIRCUIT
(Fuel tank temperature sen-
sor circuit high input) An excessively high voltage from the sensor is
sent to ECM.
Fuel level sensor unit and
fuel pump Ground Voltage (V)
Connector Terminal
C5 4 Ground Approx. 5
Revision: 2010 May2011 QX56

P0182, P0183 FTT SENSOREC-275
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connector.
4.CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Check the continuity between “fuel level sensor unit and fuel pump” harness connector and “combination
meter” harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between “fuel level s ensor unit and fuel pump” and “combination meter”
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connector.
6.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-275, "
Component Inspection (Fuel Tank Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace “fuel level sensor unit and fuel pump”. Refer to FL-5, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Fuel Tank Temperature Sensor)INFOID:0000000006288294
1.CHECK FUEL TANK TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness connector.
3. Remove fuel level sensor unit.
4. Check resistance between “fuel level sensor unit and fuel pump ” terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace “fuel level sensor unit and fuel pump”.
Fuel level sensor unit and fuel pump Combination meter
Continuity
Connector Terminal Connector Terminal
C5 5 M34 24 Existed
Terminals Condition Resistance (k Ω)
4 and 5 Temperature [ °C ( °F)] 20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
JMBIA0167ZZ
Revision: 2010 May2011 QX56

EC-276
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0190, P0192,
P0193 FRP SENSOR
P0190, P0192, P0193 FRP SENSOR
DTC LogicINFOID:0000000006288295
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 the engine ON and wait at least 60 seconds.
2. Check DTC or 1st trip DTC.
Is DTC or 1st trip DTC detected?
YES >> Proceed to EC-276, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288296
1.CHECK FRP SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect FRP sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between FRP sensor harness connector terminals.
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK FRP SENSOR POWER SUPPLY-II
Check the voltage between FRP sensor harness connector and the ground.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0190 Fuel rail pressure sensor
circuit low input and high in-
put Signal voltage from the fuel rail pressure
sensor remains at more than 4.84 V /
less than 0.2 V for 5 seconds or more.  Harness or connectors
(Fuel rail pressure sensor circuit is open or
shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Low fuel pressure sensor circuit is open or
shorted.)
(The electrically-controlled cooling fan cou-
pling circuit is open or shorted)
 Fuel rail pressure sensor
 Power steering pressure sensor
 Low fuel pressure sensor
 Electrically-controlled cooling fan coupling
P0192
Fuel rail pressure sensor
circuit low input Signal voltage from the fuel rail pressure
sensor remains at less than 0.37 V for 5
seconds or more.
P0193 Fuel rail pressure sensor
circuit high input Signal voltage from the fuel rail pressure
sensor remains at more than 3.46 V for 5
seconds or more.
FRP sensor
Voltag e
(Approx.)
Connector +
−
terminal
F26 1 3 5 V
Revision: 2010 May2011 QX56

P0190, P0192, P0193 FRP SENSOR
EC-277
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK FRP SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
Check the continuity between ECM harness connector and the ground.
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
+
−Vo l ta g e
(Approx.)
FRP sensor
Connector Terminal F26 1 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Low fuel pressure sensor F25 3
Power steering pressure sensor F35 1
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 3 F111 40 Existed
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
Revision: 2010 May2011 QX56

EC-278
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0190, P0192,
P0193 FRP SENSOR
6.CHECK FRP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK FRP SENSOR
Refer to EC-278, "
Component Inspection (Fuel Rail Pressure Sensor)".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (Fuel Rail Pressure Sensor)INFOID:0000000006288297
1.CHECK FRP SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “FUEL PRES SEN V” indication.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check FRP sensor signal voltage.
Is the inspection result normal?
YES >> INSPECTION END.
NO >> Replace FRP sensor. Refer to EM-48, "
Exploded View".
+−
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 2 F111 31 Existed
Monitor Item Condition Values/Status
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.)
ECM
Connector Terminal Connector Terminal
F 111 3 1 F 111 4 0 [Engine is running]
 Warm-up condition
 Idle speed
0.98 – 1.2 V
[Engine is running]
 Warm-up condition
 Revving engine from idle to 4,000 rpm quickly 1.1 – 2.9 V
Revision: 2010 May2011 QX56

P0191 FRP SENSOREC-279
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0191 FRP SENSOR
DTC LogicINFOID:0000000006288298
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 the engine and warm it up to the normal operating temperature. NOTE:
Warm up the engine until “COOLAN TEMP/S” on “DATA MONITOR” of CONSULT-III reaches at least
70 °C (158 °F).
2. Turn the ignition switch OFF and cool the engi ne until the engine coolant temperature reaches 35 °C
(95 °F) or less.
CAUTION:
 The difference between air temperature an d engine coolant temperature must be 5°C or less.
 Do not turn ignition switch ON.
3. Turn ignition switch ON and wait at least 60 seconds.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-279, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288299
1.CHECK FRP SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect FRP sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between FRP s ensor harness connector terminals.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0191 Fuel rail pressure sensor Fuel rail pressure re
mains at more than
1.5 MPa (15 bar, 15.3 kg/cm
2, 217.5 psi)
for 0.2 seconds or more during ignition
ON.  Harness or connectors
(Fuel rail pressure sensor circuit is open or
shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Low fuel pressure sensor circuit is open or
shorted.)
(The electrically-controlled cooling fan cou-
pling circuit is open or shorted)
 Fuel rail pressure sensor
 Power steering pressure sensor
 Low fuel pressure sensor
 Electrically-controlled cooling fan coupling
Revision: 2010 May2011 QX56

EC-280
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0191 FRP SENSOR
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK FRP SENSOR POWER SUPPLY-II
Check the voltage between FRP sensor harness connector and the ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK FRP SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
Check the continuity between ECM harness connector and the ground.
FRP sensor Voltag e
(Approx.)
Connector +
−
terminal
F26 1 3 5 V
+ −Voltag e
(Approx.)
FRP sensor
Connector Terminal F26 1 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Low fuel pressure sensor F25 3
Power steering pressure sensor F35 1
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 3 F111 40 Existed
Revision: 2010 May2011 QX56

P0191 FRP SENSOREC-281
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Is inspection result normal?
YES >> Check intermittent incident. Refer to
GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
6.CHECK FRP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK FRP SENSOR
Refer to EC-278, "
Component Inspection (Fuel Rail Pressure Sensor)".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (Fuel Rail Pressure Sensor)INFOID:0000000006288360
1.CHECK FRP SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “FUEL PRES SEN V” indication.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check FRP sensor signal voltage.
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 2 F111 31 Existed
Monitor Item Condition Values/Status
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
Revision: 2010 May2011 QX56