2007 INFINITI M35 fuel pressure

DTC P0461 FUEL LEVEL SENSOR
EC-1171
[VK45DE]
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Revision: 2007 April2007 M35/M45
DTC P0461 FUEL LEVEL SENSORPFP:25060
Component DescriptionNBS005IU
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 “unified meter and A/C amp.”. The “unified meter and A/C
amp.” 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.

Fuel level sensor unit and fuel pump (1)

Fuel pressure regulator (2)

Fuel tank temperature sensor (3)
On Board Diagnosis LogicNBS005IV
NOTE:

If DTC P0461 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-865, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P0461 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to EC-868, "
DTC U1010 CAN COMMUNICATION" .
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 CheckNBS005IW
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,
"FUEL TANK" .
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-790, "
FUEL PRESSURE RELEASE" .
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.
PBIB2707E
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 distance.

Harness or connectors
(The CAN communication line is open or
shorted)

Harness or connectors
(The sensor circuit is open or shorted)

Unified meter and A/C amp.

Fuel level sensor

EC-1172
[VK45DE]
DTC P0461 FUEL LEVEL SENSOR
Revision: 2007 April2007 M35/M45
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-1172, "
Diagnostic 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-790, "
FUEL PRESSURE RELEASE" .
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-1172, "
Diagnostic Procedure" .
Diagnostic ProcedureNBS005IX
1. CHECK DTC WITH “UNIFIED METER AND A/C AMP.”
Refer to DI-31, "
SELF-DIAG RESULTS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Signal Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-857, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Removal and InstallationNBS005IY
FUEL LEVEL SENSOR
Refer to FL-4, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
SEF195Y

DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
EC-1173
[VK45DE]
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Revision: 2007 April2007 M35/M45
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUITPFP:25060
Component DescriptionNBS005IZ
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 “unified meter and A/C amp.”. The “unified meter and A/C
amp.” 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.

Fuel level sensor unit and fuel pump (1)

Fuel pressure regulator (2)

Fuel tank temperature sensor (3)
On Board Diagnosis LogicNBS005J0
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-865, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P0462 or P0463 is displayed with DTC U1010, first perform the trouble diagnosis for DTC
U1010. Refer to EC-868, "
DTC U1010 CAN COMMUNICATION" .
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation ProcedureNBS005J1
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-1174, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB2707E
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)

Unified meter and A/C amp.

Fuel level sensor P0463
0463Fuel level sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF195Y

DTC P2A00, P2A03 A/F SENSOR 1
EC-1365
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Revision: 2007 April2007 M35/M45
DTC P2A00, P2A03 A/F SENSOR 1PFP:22693
Component DescriptionNBS005PD
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeNBS005PE
Specification data are reference values.
On Board Diagnosis LogicNBS005PF
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation ProcedureNBS005PG
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 idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 1.5 V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P2A00
2A00
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit range/performance

The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side
for a specified period.

The A/F signal computed by ECM from the A/F
sensor 1 signal is shifted to the rich side for a
specified period.

A/F sensor 1

A/F sensor 1 heater

Fuel pressure

Fuel injector

Intake air leaks P2A03
2A03
(Bank 2)

FUEL PUMP
EC-1395
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Revision: 2007 April2007 M35/M45
FUEL PUMPPFP:17042
DescriptionNBS005Q1
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.

Fuel level sensor unit and fuel pump (1)

Fuel pressure regulator (2)

Fuel tank temperature sensor (3)
CONSULT-II Reference Value in Data Monitor ModeNBS005Q2
Specification data are reference values.
Sensor Input signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and crankingOperates.
When engine is stoppedStops in 1.5 seconds.
Except as shown aboveStops.
PBIB2707E
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLY

For 1 seconds after turning ignition switch: ON

Engine running or crankingON

Except above OFF

FUEL PUMP
EC-1397
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Revision: 2007 April2007 M35/M45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureNBS005Q4
1. CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose (1) with two fingers.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check voltage between ECM terminal 113 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
38 G/BFuel pump control module
(FPCM) check[When cranking engine]Approximately 0V
[Engine is running]

Warm-up condition

Idle speed4 - 6V
39 B/RFuel pump control module
(FPCM)[When cranking engine]0 - 0.5V
[Engine is running]

Warm-up condition

Idle speed8 - 12V
113 GR Fuel pump relay[Ignition switch: ON]

For 1 second after turning ignition switch ON
[Engine is running]0 - 1.5V
[Ignition switch: ON]

More than 1 second after turning ignition
switch ONBATTERY VOLTAGE
(11 - 14V)
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after ignition switch is turned ON.
PBIB2721E
Voltage: Battery voltage
PBIB1187E

EC-1422
[VK45DE]
IGNITION SIGNAL
Revision: 2007 April2007 M35/M45
3. Check resistance between ignition coil terminals as follows.
4. If NG, replace ignition coil with power transistor.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Reconnect all harness connectors disconnected.
7. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.

It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
17. If NG, replace ignition coil with power transistor.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
1 and 2 Except 0 or ∞
1 and 3
Except 0
2 and 3
Spark should be generated.
PBIB0847E
PBIB2697E
PBIB2325E

EC-1440
[VK45DE]
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: 2007 April2007 M35/M45
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureNBS005QT
Idle Speed and Ignition TimingNBS005QU
*: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights, heater fan & rear window defogger)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueNBS005QV
Mass Air Flow SensorNBS005QW
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorNBS005QX
Engine Coolant Temperature SensorNBS005QY
Fuel Tank Temperature SensorNBS005QZ
Crankshaft Position Sensor (POS)NBS005R0
Refer to EC-1081, "Component Inspection" .
Camshaft Position Sensor (PHASE)NBS005R1
Refer to EC-1088, "Component Inspection" .
A/F Sensor 1 HeaterNBS005R2
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed No load* (in P or N position) 650 ± 50 rpm
Air conditioner: ON In P or N position 650 rpm or more
Ignition timing In P or N position 12° ± 5° BTDC
Condition Calculated load value% (Using CONSULT-II or GST)
At idle14 - 33
At 2,500 rpm12 - 25
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle0.9 - 1.2V*
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g·m/sec at idle*
7.0 - 20.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.800 - 2.200
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Temperature °C (°F) Resistance kΩ
20 (68)2.3 - 2.7
50 (122)0.79 - 0.90
Resistance [at 25°C (77°F)] 2.3 - 4.3Ω