2005 INFINITI QX4 fuel pump

AUDIO
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NOTE:
1. The following noise results from variations in field strength, such as fading noise and multi-path noise, or
external noise from trains and other sources. It is not a malfunction.

Fading noise: This noise occurs because of variations in the field strength in a narrow range due to moun-
tains or buildings blocking the signal.

Multi-path noise: This noise results from the waves sent directly from the broadcast station arriving at the
antenna at a different time from the waves which reflect off mountains or buildings.
FOR CD ONLY
Noise InspectionEKS00BIH
The vehicle itself can be a source of noise if noise prevention parts or electrical equipment is malfunctioning.
Check if noise is caused and/or changed by engine speed, ignition switch turned to each position, and opera-
tion of each piece of electrical equipment, and determine the cause.
NOTE:
The source of the noise can be found easily by listening to the noise while removing the fuses of electrical
components, one by one.
TYPE OF NOISE AND POSSIBLE CAUSE
Symptom Possible cause
CD cannot be inserted.

CD

Audio unit CD cannot be ejected.
The CD cannot be played.
The sound skips, stops suddenly, or is distorted.
Occurrence condition Possible cause
Occurs only when engine is ON.A continuous growling noise occurs. The speed of
the noise varies with changes in the engine speed.

Ignition components
A whistling noise occurs while the engine speed is
high. A booming noise occurs while the engine is
running and the lighting switch is ON.

Generator
The occurrence of the noise is linked with the operation of the fuel pump.

Fuel pump condenser
Noise only occurs when various
electrical components are oper-
ating.A cracking or snapping sound occurs with the
operation of various switches.

Relay malfunction, audio unit malfunction
The noise occurs when various motors are operat-
ing.

Motor case ground

Motor
The noise occurs constantly, not just under certain conditions.

Rear defogger coil malfunction

Open circuit in printed heater

Poor ground of antenna amplifier or
antenna feeder line
A cracking or snapping sound occurs while the vehicle is being driven, especially
when it is vibrating excessively.

Ground wire of body parts

Ground due to improper part installation

Wiring connections or a short circuit

DI-6
COMBINATION METERS
Revision: October 20052005 QX56
POWER SUPPLY AND GROUND CIRCUIT
Power is supplied at all times

through 10A fuse [No.19, located in the fuse block (J/B)]

to combination meter terminal 8.
With the ignition switch in the ON or START position, power is supplied

through 10A fuse [No.14, located in the fuse block (J/B)]

to combination meter terminal 24.
With the ignition switch in the ACC or ON position, power is supplied

through 10A fuse [No.4, located in the fuse block (J/B)]

to combination meter terminal 1.
Ground is supplied

to combination meter terminal 17

through body grounds M57, M61 and M79.
WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature.
ECM provides an engine coolant temperature signal to combination meter via CAN communication lines.
ENGINE OIL PRESSURE GAUGE
The engine oil pressure gauge indicates the engine oil pressure.
The engine oil pressure gauge is regulated by the unified meter control unit and input from the oil pressure
sensor.
A/T OIL TEMPERATURE GAUGE
The A/T oil temperature gauge indicates the A/T fluid temperature.
TCM (transmission control module) provides an A/T fluid temperature signal to combination meter via CAN
communication lines.
V O LTA G E G A U G E
The voltage gauge indicates the battery/charging system voltage.
The voltage gauge is regulated by the unified meter control unit.
TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm).
ECM provides an engine speed signal to combination meter via CAN communication lines.
FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by the unified meter control unit and a variable resistor signal supplied

to combination meter terminal 15

through fuel level sensor unit and fuel pump terminal 2

through fuel level sensor unit and fuel pump terminal 5

from combination meter terminal 16.
SPEEDOMETER
ABS actuator and electric unit (control unit) provides a vehicle speed signal to the combination meter via CAN
communication lines.
CAN COMMUNICATION SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .

COMBINATION METERS
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Component Parts and Harness Connector LocationEKS00BBV
1. Combination meter M24 2. Fuel level sensor unit and fuel pump
C5 (view with fuel tank removed)3. ECM
(view with battery removed)
4. ECM harness connector E16 5. ABS actuator and electric unit (con-
trol unit) E1256. Oil pressure sensor F4
7. A. Oil pan (upper) 8. A/T assembly F9
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COMBINATION METERS
Revision: October 20052005 QX56
Fuel Level Sensor Unit InspectionEKS00BC9
FUEL LEVEL SENSOR UNIT
The following symptoms do not indicate a malfunction.

Depending on vehicle position or driving circumstance, the fuel in the tank shifts and the indication may
fluctuate.

If the vehicle is fueled with the ignition switch ON, the indication will update slowly.

If the vehicle is tilted when the ignition switch is turned ON, fuel in the tank may flow to one direction
resulting in a change of reading.
LOW-FUEL WARNING LAMP
Depending on vehicle posture or driving circumstances, the fuel level in the tank varies, and the warning lamp
ON timing may be changed.
1. CHECK SELF-DIAGNOSIS
Perform the combination meter self-diagnosis. Refer to DI-13, "
SELF-DIAGNOSIS FUNCTION" .
OK or NG
OK >> GO TO 2.
NG >> Replace the combination meter. Refer to IP-13, "
Combination Meter" .
2. CHECK HARNESS CONNECTOR
1. Turn the ignition switch OFF.
2. Check combination meter and fuel level sensor unit and fuel pump terminals (meter-side, and harness-
side) for poor connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace terminals or connectors.
3. CHECK HARNESS CONNECTOR OUTPUT SIGNAL
1. Disconnect fuel level sensor unit and fuel pump connector.
2. Turn ignition switch ON.
3. Check voltage between combination meter harness connector
M24 terminal 15 (Y/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" . Battery voltageWKIA1816E

COMBINATION METERS
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4. CHECK HARNESS FOR OPEN OR SHORT CIRCUIT
1. Turn the ignition switch OFF.
2. Disconnect combination meter connector M24.
3. Check continuity between fuel level sensor unit and fuel pump
harness connector C5 (A) terminal 2 (Y/L) and combination
meter harness connector M24 (B) terminal 15 (Y/L).
4. Check continuity between fuel level sensor unit and fuel pump
harness connector C5 (A) terminal 2 (Y/L) and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK FUEL LEVEL SENSOR CIRCUIT
1. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and fuel level sensor unit and fuel pump
harness connector C5 terminal 5 (B/P).
2. Check continuity between fuel level sensor unit and fuel pump
harness connector C5 terminal 5 (B/P) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK FUEL LEVEL SENSOR UNIT
Check the fuel level sensor unit. Refer to DI-25, "
FUEL LEVEL SENSOR UNIT CHECK" .
OK or NG
OK >> GO TO 7.
NG >> Replace the fuel level sensor unit. Refer to FL-5, "
Removal and Installation" .
7. CHECK INSTALLATION CONDITION
Check fuel level sensor unit installation, and determine whether the float arm interferes or binds with any of the
internal components in the fuel tank.
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NG >> Install the fuel level sensor unit properly.Continuity should exist.
Continuity should not exist.
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Continuity should exist.
Continuity should not exist.
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COMBINATION METERS
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Electrical Components InspectionEKS00BCC
FUEL LEVEL SENSOR UNIT CHECK
For removal, refer to FL-5, "Removal and Installation" .
Check Fuel Level Sensor Unit and Fuel Pump
Check resistance between fuel level sensor unit and fuel pump con-
nector terminals 2 and 5.
*1 and *2: When float rod is in contact with stopper.
Removal and Installation of Combination MeterEKS00BCD
Refer to IP-13, "Combination Meter" for removal and installation procedures.
Terminals Float position mm (in)Resistance
value Ω
(Approx.)
25*1 Empty 25.86 (1.02) 81.66
*2 Full 254.6 (10.02) 6.98
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Revision: October 20052005 QX56 DTC P2135 TP SENSOR ........................................ 604
Component Description ........................................ 604
CONSULT-II Reference Value in Data Monitor Mode
. 604
On Board Diagnosis Logic ................................... 604
DTC Confirmation Procedure ............................... 605
Wiring Diagram .................................................... 606
Diagnostic Procedure ........................................... 607
Component Inspection ......................................... 610
Removal and Installation ...................................... 610
DTC P2138 APP SENSOR ...................................... 611
Component Description ......................................... 611
CONSULT-II Reference Value in Data Monitor Mode
.. 611
On Board Diagnosis Logic .................................... 611
DTC Confirmation Procedure ............................... 612
Wiring Diagram .................................................... 613
Diagnostic Procedure ........................................... 614
Component Inspection ......................................... 618
Removal and Installation ...................................... 618
IGNITION SIGNAL .................................................. 619
Component Description ........................................ 619
Wiring Diagram .................................................... 620
Diagnostic Procedure ........................................... 625
Component Inspection ......................................... 629
Removal and Installation ...................................... 630
INJECTOR CIRCUIT ............................................... 631
Component Description ........................................ 631
CONSULT-II Reference Value in Data Monitor Mode
. 631
Wiring Diagram .................................................... 632
Diagnostic Procedure ........................................... 633
Component Inspection ......................................... 636
Removal and Installation ...................................... 636
FUEL PUMP CIRCUIT ............................................ 637
Description ........................................................... 637
CONSULT-II Reference Value in Data Monitor Mode
. 637
Wiring Diagram .................................................... 638
Diagnostic Procedure ........................................... 639
Component Inspection ......................................... 642
Removal and Installation ...................................... 642
REFRIGERANT PRESSURE SENSOR ................. 643
Component Description ........................................ 643Wiring Diagram .....................................................644
Diagnostic Procedure ...........................................645
Removal and Installation ......................................647
ELECTRICAL LOAD SIGNAL ................................648
Description ............................................................648
CONSULT-II Reference Value in Data Monitor Mode
.648
Diagnostic Procedure ...........................................648
ICC BRAKE SWITCH .............................................649
Component Description ........................................649
CONSULT-II Reference Value in Data Monitor Mode
.649
Wiring Diagram .....................................................650
Diagnostic Procedure ...........................................651
Component Inspection ..........................................656
ASCD BRAKE SWITCH .........................................657
Component Description ........................................657
CONSULT-II Reference Value in Data Monitor Mode
.657
Wiring Diagram .....................................................658
Diagnostic Procedure ...........................................659
Component Inspection ..........................................663
ASCD INDICATOR ..................................................664
Component Description ........................................664
CONSULT-II Reference Value in Data Monitor Mode
.664
Wiring Diagram .....................................................665
Diagnostic Procedure ...........................................666
MIL AND DATA LINK CONNECTOR ......................667
Wiring Diagram .....................................................667
SERVICE DATA AND SPECIFICATIONS (SDS) ....669
Fuel Pressure .......................................................669
Idle Speed and Ignition Timing .............................669
Calculated Load Value ..........................................669
Mass Air Flow Sensor ...........................................669
Intake Air Temperature Sensor .............................669
Engine Coolant Temperature Sensor ...................669
A/F Sensor 1 Heater .............................................669
Heated Oxygen sensor 2 Heater ..........................669
Crankshaft Position Sensor (POS) .......................669
Camshaft Position Sensor (PHASE) ....................669
Throttle Control Motor ...........................................669
Injector ..................................................................670
Fuel Pump ............................................................670

PRECAUTIONS
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Do not operate fuel pump when there is no fuel in lines.

Tighten fuel hose clamps to the specified torque.

Do not depress accelerator pedal when starting.

Immediately after starting, do not rev up engine unneces-
sarily.

Do not rev up engine just prior to shutdown.

When installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on installation location.
–Keep the antenna as far as possible from the electronic
control units.
–Keep the antenna feeder line more than 20 cm (8 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
–Adjust the antenna and feeder line so that the standing-
wave radio can be kept smaller.
–Be sure to ground the radio to vehicle body.
Wiring Diagrams and Trouble DiagnosisUBS00KZ3
When you read wiring diagrams, refer to the following:

GI-15, "How to Read Wiring Diagrams"

PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit
When you perform trouble diagnosis, refer to the following:

GI-11, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES"

GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident"
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