2001 INFINITI QX4 02 sensor

SEF018S
Component DescriptionNBEC0626The 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 ECM.
It consists of two parts, one is mechanical float and the other side
is variable resistor. Fuel level sensor output voltage changes
depending on the movement of the fuel mechanical float.
On Board Diagnostic LogicNBEC0627ECM receives two signals from the fuel level sensor circuit.
One is fuel level sensor power supply circuit, and the other is fuel
level sensor ground circuit.
This diagnosis indicates the former, to detect open or short circuit
malfunction.
Malfunction is detected when an excessively low or high voltage is
sent from the sensor is sent to ECM.
Possible CauseNBEC0628IFuel level sensor circuit
(The fuel level sensor circuit is open or shorted.)
IFuel level sensor
DTC Confirmation ProcedureNBEC0629NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 11V at ignition switch ªONº.
SEF195Y
WITH CONSULT-IINBEC0629S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-415.
WITH GSTNBEC0629S02Follow the procedure ªWITH CONSULT-IIº above.
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DTC P0464 FUEL LEVEL SENSOR CIRCUIT
Component Description
EC-413

Wiring DiagramNBEC0630
MEC984C
DTC P0464 FUEL LEVEL SENSOR CIRCUIT
Wiring Diagram
EC-414

Diagnostic Procedure=NBEC0631
1 CHECK FUEL LEVEL SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit harness connector.
3. Turn ignition switch ªONº.
4. Check voltage between fuel level sensor unit terminal 3 and ground, ECM terminal 83 and ground with CONSULT-II or
tester.
SEF374Z
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M2, B1 and M94, F27
IHarness for open or short between combination meter and fuel level sensor unit
©Repair or replace harness or connectors.
3 CHECK FUEL LEVEL SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between fuel level sensor unit terminal 2 and body ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to power in harness or connectors.
4 CHECK FUEL LEVEL SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 59 and fuel level sensor terminal 2. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
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DTC P0464 FUEL LEVEL SENSOR CIRCUIT
Diagnostic Procedure
EC-415

5 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M2, B1
IHarness connectors M94, F27
IHarness for open between ECM and fuel level sensor
©Repair open circuit or short to power in harness on connectors.
6 CHECK FUEL LEVEL SENSOR
Refer to EL-108, ªFuel Level Sensor Unit Checkº.
OK or NG
OK©GO TO 7.
NG©Replace fuel level sensor unit.
7 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P0464 FUEL LEVEL SENSOR CIRCUIT
Diagnostic Procedure (Cont'd)
EC-416

AEC110
Component Description=NBEC0242The vehicle speed sensor is installed in the transaxle. It contains a
pulse generator which provides a vehicle speed signal to the
speedometer. The speedometer then sends a signal to the ECM.
ECM Terminals and Reference ValueNBEC0669Specification 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.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
86 W/L Vehicle speed sensor[Engine is running]
IJack up front wheels.
IIn 1st gear position
I10 km/h (6 MPH)Approximately 2.5V
SEF583X
[Engine is running]
IJack up front wheels.
IIn 2nd gear position
I30 km/h (19 MPH)Approximately 2.0V
SEF584X
On Board Diagnosis LogicNBEC0244Malfunction is detected when the almost 0 km/h (0 MPH) signal
from vehicle speed sensor is sent to ECM even when vehicle is
being driven.
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DTC P0500 VEHICLE SPEED SENSOR (VSS)
Component Description
EC-417

Possible CauseNBEC0514IHarness or connector
(The vehicle speed sensor circuit is open or shorted.)
IVehicle speed sensor
DTC Confirmation ProcedureNBEC0245CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted
in the shop or by driving the vehicle. If a road test is expected
to be easier, it is unnecessary to lift the vehicle.
SEF196Y
WITH CONSULT-IINBEC0245S011) Start engine (TCS switch ªOFFº).
2) Read ªVHCL SPEED SEº in ªDATA MONITORº mode with
CONSULT-II. The vehicle speed on CONSULT-II should
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.
If NG, go to ªDiagnostic Procedureº, EC-421.
If OK, go to following step.
3) Select ªDATA MONITORº mode with CONSULT-II.
4) Warm engine up to normal operating temperature.
5) Maintain the following conditions for at least 10 consecutive
seconds.
ENG SPEED 1,800 - 6,000 rpm
COOLAN TEMP/S More than 70ÉC (158ÉF)
B/FUEL SCHDL 5.5 - 14.0 msec
Selector lever Suitable position
PW/ST SIGNAL OFF
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-421.
Overall Function CheckNBEC0246Use 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 GSTNBEC0246S011) Lift up drive wheels.
2) Start engine.
3) Read vehicle speed sensor signal in ªMODE 1º with GST.
The vehicle speed sensor on GST should be able to exceed
DTC P0500 VEHICLE SPEED SENSOR (VSS)
Possible Cause
EC-418

10 km/h (6 MPH) when rotating wheels with suitable gear posi-
tion.
4) If NG, go to ªDiagnostic Procedureº, EC-421.
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DTC P0500 VEHICLE SPEED SENSOR (VSS)
Overall Function Check (Cont'd)
EC-419

Wiring DiagramNBEC0247
MEC965C
DTC P0500 VEHICLE SPEED SENSOR (VSS)
Wiring Diagram
EC-420