2009 INFINITI QX56 sensor

P0456 EVAP CONTROL SYSTEMEC-263
< COMPONENT DIAGNOSIS > [VK56DE]
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OK >> GO TO 15.
NG >> Repair or reconnect the hose.
15.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-229, "Component Inspection"
.
OK or NG
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-181, "Component Inspection"
.
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
17.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-239, "Component Inspection"
.
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18.CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to EC-37, "Description"
.
OK or NG
OK >> GO TO 19.
NG >> Repair or reconnect the hose.
19.CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 20.
20.CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-409
.
OK or NG
OK >> GO TO 21.
NG >> Repair or replace hoses and tubes.
21.CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 22.
NG >> Repair or replace hose, tube or filler neck tube.
22.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-411, "Component Inspection"
.
OK or NG
OK >> GO TO 23.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
23.CHECK FUEL LEVEL SENSOR
Refer to MWI-34, "Component Inspection"
.
OK or NG
OK >> GO TO 24.
Revision: December 20092009 QX56

EC-264
< COMPONENT DIAGNOSIS >[VK56DE]
P0456 EVAP CONTROL SYSTEM
NG >> Replace fuel level sensor unit.
24.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000003771528
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
3. If out of specification, replace fuel filler cap as an assembly.
CAUTION:
Use only a genuine fuel filler cap as a replacement. If an incor-
rect fuel filler cap is used, the MIL may come on.
SEF445Y
Pressure:
15.3 - 20.0 kPa (0.156 - 0.204 kg/cm2, 2.22 -
2.90 psi)
Vacuum: −6.0 to −3.3 kPa ( −0.061 to −0.034 kg/cm
2,
− 0.87 to −0.48 psi)
SEF943S
Revision: December 20092009 QX56

P0460 FUEL LEVEL SENSOREC-265
< COMPONENT DIAGNOSIS > [VK56DE]
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P0460 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000003771529
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicINFOID:0000000003771530
NOTE:

If DTC P0460 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P0460 is displayed with DTC P0607, firs t perform the trouble diagnosis for DTC P0607. Refer
to EC-284
.
When the vehicle is parked, naturally the fuel level in the fuel tank is stable. It means that output signal of the
fuel level sensor does not change. If ECM senses sloshi ng signal from the sensor, fuel level sensor malfunc-
tion is detected.
DTC Confirmation ProcedureINFOID:0000000003771531
1. If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and wait maximum of 2 consecutive minutes.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-265, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771532
1.CHECK COMBINATION METER FUNCTION
Refer to MWI-5, "METER SYSTEM : System Description"
.
OK or NG
OK >> GO TO 2.
NG >> Go to MWI-34, "Component Inspection"
.
2.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0460
0460 Fuel level sensor circuit
noise Even though the vehicle is parked, a signal be-
ing varied is sent from the fuel level sensor to
ECM.  Harness or connectors
(The CAN communication line is open or
shorted)
 Harness or connectors
(The sensor circuit is open or shorted)
 Combination meter
 Fuel level sensor
Revision: December 20092009 QX56

EC-266
< COMPONENT DIAGNOSIS >[VK56DE]
P0460 FUEL LEVEL SENSOR
>>
INSPECTION END
Revision: December 20092009 QX56

P0461 FUEL LEVEL SENSOREC-267
< COMPONENT DIAGNOSIS > [VK56DE]
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P0461 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000003771533
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicINFOID:0000000003771534
NOTE:

If DTC P0461 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P0461 is displayed with DT C P0607, first perform the trouble diagnosis for DTC P0607. Refer
to EC-284
.
Driving long distances naturally affect fuel gauge level.
This diagnosis detects the fuel gauge malfunction of the gauge not moving even after a long distance has
been driven.
Overall Function CheckINFOID:0000000003771535
Use this procedure to check the overall function of the f uel level sensor function. During this check, a 1st trip
DTC might not be confirmed.
WARNING:
When performing following procedure, be sure to observe the handling of the fuel. Refer to FL-11,
"Removal and Installation".
TESTING CONDITION:
Before starting overall function check, preparation of draining fuel and refilling fuel is required.
WITH CONSULT-III
NOTE:
Start from step 10, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/
8 Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line, refer to EC-487, "Fuel Pressure Check"
.
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch OFF and wait at least 10 seconds then turn ON.
6. Select “FUEL LEVEL SE” in “DAT A MONITOR” mode with CONSULT-III.
7. Check “FUEL LEVEL SE” output voltage and note it.
8. Select “FUEL PUMP” in “ACT IVE TEST” mode with CONSULT-III.
9. Touch “ON” and drain fuel approximately 30 (7-7/8 US gal, 6-5/8 Imp gal) and stop it.
10. Check “FUEL LEVEL SE” output voltage and note it.
11. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0461
0461 Fuel level sensor circuit
range/performance The output signal of the fuel level sensor does
not change within the specified range even
though the vehicle has been driven a long dis-
tance.  Harness or connectors
(The CAN communication line is open or
shorted)
 Harness or connectors
(The sensor circuit is open or shorted)
 Combination meter
 Fuel level sensor
Revision: December 20092009 QX56

EC-268
< COMPONENT DIAGNOSIS >[VK56DE]
P0461 FUEL LEVEL SENSOR
12. Check “FUEL LEVEL SE” output voltage and note it.
13. Confirm whether the voltage changes more than 0.03V during step 7 to 10 and 10 to 12.
If NG, go to EC-268, "Diagnosis Procedure"
.
WITH GST
NOTE:
Start from step 8, if it is possibl e to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/8
Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line. Refer to EC-487, "Fuel Pressure Check"
.
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch ON.
6. Drain fuel by 30 (7-7/8 US gal, 6-5/8 Imp gal) from the fuel tank using proper equipment.
7. Confirm that the fuel gauge indication varies.
8. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
9. Confirm that the fuel gauge indication varies.
10. If NG, go to EC-268, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771536
1.CHECK COMBINATION METER FUNCTION
Refer to MWI-5, "METER SYSTEM : System Diagram"
.
OK or NG
OK >> GO TO 2.
NG >> Go to MWI-34, "Component Inspection"
.
2.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Revision: December 20092009 QX56

P0462, P0463 FUEL LEVEL SENSOR
EC-269
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P0462, P0463 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000003771537
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicINFOID:0000000003771538
NOTE:

If DTC P0462 or P0463 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for
DTC U1000, U1001. Refer to EC-86
.
 If DTC P0462 or P0463 is displayed with DTC P0607, first perform the trouble diagnosis for DTC
P0607. Refer to EC-284
.
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation ProcedureINFOID:0000000003771539
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm th at battery voltage is more than 11V at ignition
switch ON.
1. Turn ignition switch ON.
2. Wait at least 5 seconds.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-269, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771540
1.CHECK COMBINATION METER FUNCTION
Refer to MWI-5
.
OK or NG
OK >> GO TO 2.
NG >> Go to MWI-34, "Component Inspection"
.
2.CHECK INTERMITTENT INCIDENT
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0462
0462 Fuel level sensor circuit
low input An excessively low voltage from the sensor is
sent to ECM.  Harness or connectors
(The CAN communication line is open or
shorted)
 Harness or connectors (The sensor circuit is open or shorted)
 Combination meter
 Fuel level sensor
P0463
0463
Fuel level sensor circuit
high input An excessively high voltage from the sensor is
sent to ECM.
Revision: December 20092009 QX56

EC-270
< COMPONENT DIAGNOSIS >[VK56DE]
P0462, P0463 FUEL LEVEL SENSOR
Refer to
GI-35, "How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Revision: December 20092009 QX56