2004 INFINITI QX56 engine

WATER PUMP
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Revision: August 20072004 QX56
WATER P UM PPFP:21020
Removal and InstallationEBS00I53
CAUTION:

When removing water pump, be careful not to get engine coolant on drive belt.

Water pump cannot be disassembled and should be replaced as a unit.
REMOVAL
1. Drain engine coolant so that no engine coolant comes out from water pump fitting hole. Refer to MA-12,
"DRAINING ENGINE COOLANT" .
CAUTION:
Perform when the engine is cold.
2. Remove the engine front undercover using power tool.
3. Remove the air duct and resonator assembly. Refer to EM-14, "
Removal and Installation" .
4. Remove the drive belt. Refer to EM-12, "
Removal and Installation" .
5. Remove the water pump pulley.
6. Remove the water pump.

Engine coolant will leak from the cylinder block, so have a receptacle ready below.
CAUTION:
Handle water pump vane so that it does not contact any other parts.
INSPECTION AFTER REMOVAL

Visually check that there is no significant dirt or rusting on the
water pump body and vane.

Make sure there is no looseness in the vane shaft, and that it
turns smoothly when rotated by hand.

If there are any unusual concerns, replace the water pump
assembly.
INSTALLATION
Installation is in the reverse order of removal.
KBIA2543E
1. Gasket 2. Water pump 3. Water pump pulley
KBIA2552E

CO-16Revision: August 2007
WATER PUMP
2004 QX56

For bleeding the air from the cooling system, refer to MA-13, "REFILLING ENGINE COOLANT" .
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant. Refer to CO-8, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up engine. Visually make sure that there are no leaks of engine coolant.

THERMOSTAT AND WATER PIPING
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Revision: August 20072004 QX56
THERMOSTAT AND WATER PIPINGPFP:21200
Removal and InstallationEBS00I54
REMOVAL
Removal of Thermostat
1. Drain engine coolant from the radiator. Refer to MA-12, "DRAINING ENGINE COOLANT" .
CAUTION:
Perform when engine is cold.
2. Remove air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove engine room cover using power tools.
4. Disconnect water suction hose from water inlet.
5. Remove water inlet and thermostat.
Removal of Thermostat Housing, Water Outlet and Heater Pipe
1. Remove intake manifold. Refer to EM-15, "REMOVAL" .
2. Remove thermostat housing, water outlet and heater pipe.
Removal of Water Cut Valve
1. Drain engine coolant from the radiator. Refer to MA-12, "DRAINING ENGINE COOLANT" .
KBIA2501E
1. Heater pipe 2. Gasket 3. Water outlet
4. Gasket 5. O-ring 6. O-ring
7. Thermostat housing 8. Rubber ring 9. Thermostat
10. Water inlet 11. Water suction hose 12. Water suction pipe
13. Gasket 14. Heater pipe

CO-18Revision: August 2007
THERMOSTAT AND WATER PIPING
2004 QX56
CAUTION:
Perform when the engine is cold.
2. Remove air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove engine room cover using power tools.
4. Disconnect heater hose (heater core side).
5. Remove heater hose bracket.
6. Disconnect the water cut valve connector.
7. Remove the water cut valve
INSPECTION AFTER REMOVAL

Place a thread so that it is caught in the valve of the thermostat.
Immerse fully in a container filled with water. Heat while stirring.

The valve opening temperature is the temperature at which the
valve opens and falls from the thread.

Continue heating. Check the full-open lift amount.

After checking the full-open lift amount, lower the water temper-
ature and check the valve closing temperature.
Standard values:
INSTALLATION
Installation is in the reverse order of removal.
Installation of Thermostat

Install the thermostat with the whole circumference of each
flange part fit securely inside the rubber ring as shown.

Install the thermostat with the jiggle valve facing upwards.
Installation of Water Outlet Pipe and Heater Pipe
First apply a neutral detergent to the O-rings, then quickly insert the insertion parts of the water outlet pipe and
heater pipe into the installation holes.
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-8, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually make sure that there is no leaks of the engine coolant.
SL C2 52 B
Thermostat
Valve opening temperature 80 - 84°C (176 - 183° F)
Full-open lift amount More than 10 mm/ 95°C (0.39 in/ 203°F)
Valve closing temperature 77°C (171°F) or higher
KBIA2502E

SERVICE DATA AND SPECIFICATIONS (SDS)
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SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Standard and LimitEBS00I55
ENGINE COOLANT CAPACITY (APPROXIMATE)
Unit: (US gal, Imp gal)
THERMOSTAT
RADIATOR
Unit: kPa (kg/cm2 , psi)
Engine coolant capacity (With reservoir tank) (MAX level) 14.4 (3 3/4, 3 1/8)
Valve opening temperature 80 - 84°C (176 - 183°F)
Maximum valve lift More than 10 mm/95°C (0.39 in/203°F)
Valve closing temperature 77°C (171°F) or higher
Reservoir cap relief pressure Standard 95 - 125 (0.97- 1.28, 14 - 18)
Leakage test pressure 137 (1.4, 20)

DI-1
DRIVER INFORMATION SYSTEM
K ELECTRICAL
CONTENTS
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SECTION DI
A
B
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Revision: August 20072004 QX56 PRECAUTION ............................................................ 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Wiring Diagrams and Trouble Diagnosis .................. 3
PREPARATION ........................................................... 4
Commercial Service Tool ......................................... 4
COMBINATION METERS ........................................... 5
System Description .................................................. 5
UNIFIED METER CONTROL UNIT ...................... 5
POWER SUPPLY AND GROUND CIRCUIT ........ 6
WATER TEMPERATURE GAUGE ........................ 6
ENGINE OIL PRESSURE GAUGE ....................... 6
A/T OIL TEMPERATURE GAUGE ........................ 6
VOLTAGE GAUGE ................................................ 6
TACHOMETER ..................................................... 6
FUEL GAUGE ....................................................... 6
SPEEDOMETER ................................................... 6
CAN COMMUNICATION SYSTEM DESCRIP-
TION ...................................................................... 6
Component Parts and Harness Connector Location ..... 7
Combination Meter ................................................... 8
CHECK .................................................................. 8
Circuit Diagram ........................................................ 9
Wiring Diagram — METER — ................................ 10
Terminals and Reference Value for Combination
Meter ...................................................................... 12
Meter/Gauge Operation and Odo/Trip Meter ......... 13
SELF-DIAGNOSIS FUNCTION .......................... 13
HOW TO INITIATE COMBINATION METER
SELF- DIAGNOSIS MODE ................................. 13
COMBINATION METER SELF-DIAGNOSIS
MODE FUNCTIONS ........................................... 13
How to Proceed With Trouble Diagnosis ................ 17
Diagnosis Flow ....................................................... 17
Power Supply and Ground Circuit Inspection ........ 18
Symptom Chart ...................................................... 19
Vehicle Speed Signal Inspection ............................ 19
Engine Oil Pressure Signal Inspection ................... 19
Water Temperature Signal Inspection .................... 21Engine Speed Signal Inspection ............................. 21
Fuel Level Sensor Unit Inspection .......................... 22
FUEL LEVEL SENSOR UNIT ............................. 22
LOW-FUEL WARNING LAMP ............................. 22
Fuel Gauge Fluctuates, Indicates Wrong Value, or
Varies ...................................................................... 24
Fuel Gauge Does Not Move to Full-position ........... 24
Electrical Components Inspection .......................... 25
FUEL LEVEL SENSOR UNIT CHECK ................ 25
Removal and Installation of Combination Meter ..... 25
COMPASS AND THERMOMETER ........................... 26
System Description ................................................. 26
OUTSIDE TEMPERATURE DISPLAY ................. 26
DIRECTION DISPLAY ......................................... 26
Wiring Diagram — COMPAS — ............................. 27
Trouble Diagnoses ................................................. 28
PRELIMINARY CHECK FOR THERMOMETER ... 28
INSPECTION/COMPASS AND THERMOME-
TER ..................................................................... 28
Calibration Procedure for Compass ....................... 29
CORRECTION FUNCTIONS OF COMPASS ...... 29
INITIAL CORRECTION PROCEDURE FOR
COMPASS ........................................................... 30
WARNING LAMPS .................................................... 31
Schematic ............................................................... 31
Wiring Diagram — WARN — .................................. 32
Oil Pressure Warning Lamp Stays Off (Ignition
Switch ON) ............................................................. 38
Oil Pressure Warning Lamp Does Not Turn Off (Oil
Pressure Is Normal) ................................................ 40
A/T INDICATOR ........................................................ 41
Wiring Diagram — AT/IND — ................................. 41
A/T Indicator Does Not Illuminate ........................... 42
WARNING CHIME ..................................................... 43
Component Parts and Harness Connector Location ... 43
System Description ................................................. 44
FUNCTION .......................................................... 44
IGNITION KEY WARNING CHIME ..................... 44
LIGHT WARNING CHIME ................................... 44
SEAT BELT WARNING CHIME ........................... 44

DI-6
COMBINATION METERS
Revision: August 20072004 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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Revision: August 20072004 QX56
Meter/Gauge Operation and Odo/Trip MeterEKS007DR
SELF-DIAGNOSIS FUNCTION
The following items can be checked during Combination Meter Self-Diagnosis Mode.

Gauge sweep and present gauge values.

Illuminates all odometer, fuel, and engine temperature segments.

Illuminates all micro controlled lamps/LED's regardless of switch configuration.

Displays estimated present battery voltage.

Displays seat belt buckle switch LH status.
HOW TO INITIATE COMBINATION METER SELF- DIAGNOSIS MODE
NOTE:
Once entered, Combination Meter Self-Diagnosis Mode will function with the ignition switch in ON or START.
Combination Meter Self-Diagnosis Mode will exit upon turning the ignition switch to OFF or ACC.
To initiate Combination Meter Self-Diagnosis Mode, refer to the following procedure.
1. Turn the ignition switch ON, while holding the odometer/trip meter switch for 5 - 8 seconds.
NOTE:
If the diagnosis function is activated the odometer/trip meter will display tESt.
COMBINATION METER SELF-DIAGNOSIS MODE FUNCTIONS
To interpret Combination Meter Self-Diagnosis Mode functions, refer to the following table.
Event Odometer Display Description of Test/Data Notes:
Odometer/trip meter A/B
switch held from 5 to 8
seconds (or until
released)tESt Initiating self-diagnosis mode
Odometer/trip meter A/B
switch engaged and
released = next test
requestedrXXXX, FAILReturn to normal opera-
tion of all lamps/LEDs and
displays hex ROM rev. If
a ROM checksum fault
exists, display alternates
between "r XXXX" and
"FAIL".
Next test requested nrXXXXDisplays hex ROM rev as
stored in NVM.
Next test requested GAGEPerforms sweep of all
gauges, then displays
present gauge values.
Performs checksum tests
on ROM and EE.Gauges sweep within 10 sec-
onds
Next test requested (All segments illuminated)Lights all odometer/trip
meter, fuel, and engine
temperature display seg-
ments.Initiating self-diagnosis mode
complete
Next test requested bulbIlluminates all micro-con-
trolled lamps/LEDs
regardless of SW configu-
ration.
Next test requested EE XX, FAILHex EE level. If EE
checksum fault exists,
display alternates
between "EE XX" and
"FAIL".
Next test requested dtXXXXHex coding of final manu-
facturing test date.