2006 INFINITI QX56 fuel pump

AV-34
AUDIO
Revision: November 20092006 QX56
Occurrence conditionPossible 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: November 20092006 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-26, "CAN COMMUNICATION" .

COMBINATION METERSDI-7
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Component Parts and Harness Connector LocationEKS00BBV
1. Fuse block (J/B)2. Combination meter M243. Fuel level sensor unit and fuel pump
C5 (view with inspection hole cover
removed)
4. ECM E16 (view with battery removed) 5. ABS actuator and electric unit (con-
trol unit) E125 6. Oil pressure sensor F4
A. Oil pan (upper)
7. A/T assembly F9
WKIA4591E

DI-22
COMBINATION METERS
Revision: November 20092006 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 and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
COM-
BINATION METER" .
Battery voltage should exist.WKIA1816E

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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 combination meter harness connector M24 (B) terminal 15 and fuel level sensor unit and fuel pump
harness connector C5 (A) terminal 2.
4. Check continuity between fuel level sensor unit and fuel pump harness connector C5 (A) terminal 2 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 (B) terminal 16 and fuel level sensor unit and fuel pump
harness connector C5 (A) terminal 5.
2. Check continuity between fuel level sensor unit and fuel pump harness connector C5 (A) terminal 5 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 IP-13, "
COMBINATION METER" .
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.
WKIA4617E
Continuity should exist.
Continuity should not exist.
WKIA4618E

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Revision: November 2009 2006 QX56
Electrical Components InspectionEKS00BCC
FUEL LEVEL SENSOR UNIT CHECK
For removal, refer to FL-6, "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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Diagnostic Procedure ..........................................
. 588
Component Inspection ........................................ . 592
ASCD INDICATOR ................................................ . 593
Component Description ....................................... . 593
CONSULT-II Reference Value in Data Monitor Mode . 593
Wiring Diagram ................................................... . 594
Diagnostic Procedure .......................................... . 595
ELECTRICAL LOAD SIGNAL ............................... . 596
Description .......................................................... . 596
CONSULT-II Reference Value in Data Monitor Mode . 596
Diagnostic Procedure .......................................... . 596
FUEL INJECTOR ................................................... . 598
Component Description ....................................... . 598
CONSULT-II Reference Value in Data Monitor Mode . 598
Wiring Diagram ................................................... . 599
Diagnostic Procedure .......................................... . 600
Component Inspection ........................................ . 603
Removal and Installation ..................................... . 603
FUEL PUMP .......................................................... . 604
Description .......................................................... . 604
CONSULT-II Reference Value in Data Monitor Mode . 604
Wiring Diagram ................................................... . 605
Diagnostic Procedure .......................................... . 606
Component Inspection ........................................ . 609
Removal and Installation ..................................... . 609
ICC BRAKE SWITCH ............................................ . 610
Component Description ....................................... . 610
CONSULT-II Reference Value in Data Monitor Mode .610
Wiring Diagram .................................................... .611
Diagnostic Procedure .......................................... .612
Component Inspection ......................................... .617
IGNITION SIGNAL ................................................. .618
Component Description ....................................... .618
Wiring Diagram .................................................... .619
Diagnostic Procedure .......................................... .624
Component Inspection ......................................... .628
Removal and Installation ..................................... .629
REFRIGERANT PRESSURE SENSOR ................. .630
Component Description ....................................... .630
Wiring Diagram .................................................... .631
Diagnostic Procedure .......................................... .632
Removal and Installation ..................................... .634
MIL AND DATA LINK CONNECTOR ..................... .635
Wiring Diagram .................................................... .635
SERVICE DATA AND SPECIFICATIONS (SDS) ... .637
Fuel Pressure ...................................................... .637
Idle Speed and Ignition Timing ............................ .637
Calculated Load Value ......................................... .637
Mass Air Flow Sensor .......................................... .637
Intake Air Temperature Sensor ............................ .637
Engine Coolant Temperature Sensor .................. .637
A/F Sensor 1 Heater ............................................ .637
Heated Oxygen sensor 2 Heater ......................... .637
Crankshaft Position Sensor (POS) ...................... .637
Camshaft Position Sensor (PHASE) ................... .637
Throttle Control Motor .......................................... .637
Fuel Injector ......................................................... .638
Fuel Pump ........................................................... .638

PRECAUTIONSEC-19
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Revision: November 2009 2006 QX56

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.
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