2005 INFINITI QX4 coolant

THERMOSTAT AND WATER PIPING
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Revision: October 20052005 QX56
THERMOSTAT AND WATER PIPINGPFP:21200
Removal and InstallationEBS00LND
REMOVAL
Removal of Thermostat
1. Drain engine coolant from the radiator. Refer to MA-13, "DRAINING ENGINE COOLANT" .
CAUTION:
Perform when engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove the engine room cover using power tools.
4. Disconnect the water suction hose from the water inlet.
5. Remove the water inlet and thermostat.
Removal of Thermostat Housing, Water Outlet and Heater Pipe
1. Remove the intake manifold. Refer to EM-15, "REMOVAL" .
2. Remove the thermostat housing, water outlet and heater pipe.
Removal of Water Cut Valve
1. Drain the engine coolant from the radiator. Refer to MA-13, "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-20Revision: October 2005
THERMOSTAT AND WATER PIPING
2005 QX56
CAUTION:
Perform when the engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove the engine room cover using power tool.
4. Disconnect the heater hose (heater core side).
5. Remove the 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-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually check for 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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Revision: October 20052005 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Standard and LimitEBS00LNE
ENGINE COOLANT CAPACITY (APPROXIMATE)
Unit: (US gal, Imp gal)
THERMOSTAT
RADIATOR
Unit: kPa (kg/cm2 , psi)
Engine coolant capacity with reservoir ("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-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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Revision: October 20052005 QX56
How to Proceed With Trouble DiagnosisEKS00BC1
1. Confirm the symptom or customer complaint.
2. Perform diagnosis according to diagnosis flow. Refer to DI-17, "
Diagnosis Flow" .
3. According to the symptom chart, repair or replace the cause of the symptom.
4. Does the meter operate normally? If so, go to 5. If not, go to 2.
5. Inspection End.
Diagnosis FlowEKS00BC2
1. CHECK WARNING INDICATOR ILLUMINATION
1. Turn ignition switch ON.
2. Make sure warning indicators (such as malfunction indicator lamp and oil pressure low/coolant tempera-
ture high warning indicator) illuminate.
Do warning indicators illuminate?
YES >> GO TO 2.
NO >> Check ignition power supply system of combination meter. Refer to DI-18, "
Power Supply and
Ground Circuit Inspection" .
2. CHECK SELF-DIAGNOSIS OPERATION OF COMBINATION METER
Perform combination meter self-diagnosis. Refer to DI-13, "
SELF-DIAGNOSIS FUNCTION" .
Does self-diagnosis function operate?
YES >> GO TO 3.
NO >> Check combination meter power supply and ground circuit. Refer to DI-18, "
Power Supply and
Ground Circuit Inspection" .
3. CHECK ODOMETER OPERATION
Check segment display status of odometer.
Is the display normal?
YES >> GO TO 4.
NO >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
4. CHECK COMBINATION METER CIRCUIT
Check indication of each meter/gauge in self-diagnosis mode.
OK or NG
OK >> Go to DI-19, "Symptom Chart" .
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
WKIA1531E
WKIA1814E

EC-7
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ECA
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

PREPARATION
EC-21
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Revision: October 20052005 QX56
KV109E0010
(J-46209)
Break-out boxMeasuring the ECM signals with a circuit tester
KV109E0080
(J-45819)
Y-cable adapterMeasuring the ECM signals with a circuit tester
(J-23688)
Engine coolant refrac-
tometerChecking concentration of ethylene glycol in en-
gine coolant Tool number
(Kent-Moore No.)
Tool nameDescription
S-NT825
S-NT826
W BIA0539E

EC-22Revision: October 2005
PREPARATION
2005 QX56
Commercial Service ToolsUBS00KZ5
Tool name
(Kent-Moore No.)Description
Leak detector
i.e.: (J-41416)Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD)Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382)Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779