2007 INFINITI QX56 fuel

DTC P0461 FUEL LEVEL SENSOR
EC-425
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P0461 FUEL LEVEL SENSOR
Component DescriptionINFOID:0000000003531921
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:0000000003531922
NOTE:
•If DTC P0461 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-145
.
•If DTC P0461 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-147
.
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:0000000003531923
Use this procedure to check the overall function of the fuel 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-10
.
TESTING CONDITION:
Before starting overall function check, preparation of draining fuel and refilling fuel is required.
WITH CONSULT-II
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-80, "
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.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0461
0461Fuel level sensor circuit
range/performanceThe 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

EC-426
< SERVICE INFORMATION >
DTC P0461 FUEL LEVEL SENSOR
6. Select “FUEL LEVEL SE” in “DATA MONITOR” mode with CON-
SULT-II.
7. Check “FUEL LEVEL SE” output voltage and note it.
8. Select “FUEL PUMP” in “ACTIVE TEST” mode with CONSULT-
II.
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).
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-426, "
Diagnosis Procedure" .
WITH GST
NOTE:
Start from step 8, 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-80, "
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-426, "
Diagnosis Procedure" .
Diagnosis ProcedureINFOID:0000000003531924
1.CHECK COMBINATION METER FUNCTION
Refer to DI-5
.
OK or NG
OK >> GO TO 2.
NG >> Go to DI-18, "
Fuel Level Sensor Unit Inspection" .
2.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Removal and InstallationINFOID:0000000003531925
FUEL LEVEL SENSOR
Refer to FL-5.
SEF195Y

DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
EC-427
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
Component DescriptionINFOID:0000000003531926
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:0000000003531927
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-145
.
•If DTC P0462 or P0463 is displayed with DTC U1010, first perform the trouble diagnosis for DTC
U1010. Refer to EC-147
.
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation ProcedureINFOID:0000000003531928
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at ignition
switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-428, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0462
0462Fuel level sensor circuit
low inputAn 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
0463Fuel level sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF195Y

EC-428
< SERVICE INFORMATION >
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
Diagnosis Procedure
INFOID:0000000003531929
1.CHECK COMBINATION METER FUNCTION
Refer to DI-5
.
OK or NG
OK >> GO TO 2.
NG >> Go to DI-18, "
Fuel Level Sensor Unit Inspection".
2.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Removal and InstallationINFOID:0000000003531930
FUEL LEVEL SENSOR
Refer to FL-5 .

EC-430
< SERVICE INFORMATION >
DTC P0500 VSS
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-430, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000003531934
Use this procedure to check the overall function of the vehicle speed sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine.
3. Read vehicle speed sensor signal in Service $01 with GST.
The vehicle speed sensor on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
4. If NG, go to EC-430, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000003531935
1.CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11
.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK COMBINATION METER FUNCTION
Refer to DI-5
.
>>INSPECTION END
ENG SPEED 1,600 - 6,000 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL 6.9 - 31.8 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
SEF196Y

EC-440
< SERVICE INFORMATION >
DTC P0603 ECM POWER SUPPLY
DTC P0603 ECM POWER SUPPLY
Component DescriptionINFOID:0000000003531952
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagnosis LogicINFOID:0000000003531953
DTC Confirmation ProcedureINFOID:0000000003531954
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
5. Repeat steps 3 and 4 for 4 times.
6. If 1st trip DTC is detected, go to EC-442, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0603
0603ECM power supply circuitECM back-up RAM system does not function
properly.• Harness or connectors
[ECM power supply (back-up) circuit is
open or shorted.]
•ECM
SEF058Y

DTC P0850 PNP SWITCH
EC-453
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-455, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000003531969
Use this procedure to check the overall function of the park/neutral position (PNP) switch circuit. During this
check, a 1st trip DTC might not be confirmed.
WITH GST
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 102 (PNP switch signal)
and ground under the following conditions.
3. If NG, go to EC-455, "
Diagnosis Procedure".
ENG SPEED 1,000 - 6,375 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
SEF213Y
Condition (Gear position) Voltage V (Known-good data)
P or N position Approx. 0
Except the above positionBATTERY VOLTAGE
(11 - 14V)
MBIB0043E

EC-466
< SERVICE INFORMATION >
DTC P1148, P1168 CLOSED LOOP CONTROL
DTC P1148, P1168 CLOSED LOOP CONTROL
On Board Diagnosis LogicINFOID:0000000003531980
These self-diagnoses have the one trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
11 4 8
(Bank 1)
Closed loop control
functionThe closed loop control function for bank 1 does
not operate even when vehicle is driving in the
specified condition.• Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
• Air fuel ratio (A/F) sensor 1
• Air fuel ratio (A/F) sensor 1 heater P1168
11 6 8
(Bank 2)The closed loop control function for bank 2 does
not operate even when vehicle is driving in the
specified condition.