2006 INFINITI QX56 engine coolant

THERMOSTAT AND WATER PIPINGCO-21
C
DE
F
G H
I
J
K L
M A
CO
Revision: November 2009 2006 QX56
THERMOSTAT AND WATER PIPINGPFP:21200
Removal and InstallationEBS00REG
REMOVAL
Removal of Thermostat
1. Drain engine coolant from the radiator. Refer to CO-11, "DRAINING ENGINE COOLANT" .
CAUTION:
Perform when engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-15, "
Removal and Installation" .
3. Remove the engine room cover using power tool.
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-17, "Removal and Installation" .
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 CO-11, "DRAINING ENGINE COOLANT" .
KBIA2501E
1. Heater pipe2. 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-22Revision: November 2009
THERMOSTAT AND WATER PIPING
2006 QX56
CAUTION:
Perform when the engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-15, "
Removal and Installation" .
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.
SLC252B
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)CO-23
C
DE
F
G H
I
J
K L
M A
CO
Revision: November 2009 2006 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Standard and LimitEBS00REH
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 temperature80 - 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: 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" .

EC-7
C
DE
F
G H
I
J
K L
M
EC A
Revision: November 2009 2006 QX56
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

PREPARATIONEC-21
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
KV109E0010
(J-46209)
Break-out boxMeasuring the ECM signals with a circuit tester
KV109E0080
(J-45819)
Y-cable adapter Measuring the ECM signals with a circuit tester
(J-23688)
Engine coolant refrac-
tometer Checking concentration of ethylene glycol in en-
gine coolant
Tool number
(Kent-Moore No.)
Tool name
Description
S-NT825
S-NT826
WBIA0539E

EC-22Revision: November 2009
PREPARATION
2006 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

EC-24Revision: November 2009
ENGINE CONTROL SYSTEM
2006 QX56
Multiport Fuel Injection (MFI) SystemUBS00KZ7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input signal to ECMECM functionActuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor
Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery Battery voltage*
3
Power steering pressure sensorPower steering operation
Heated oxygen sensor 2 Density of oxygen in exhaust gas*
1
ABS actuator and electric unit (control unit)VDC/TCS operation command*2
Air conditioner switch
Air conditioner operation*2
Wheel sensorVehicle speed*2