2006 INFINITI QX56 cooling

CO-12Revision: November 2009
ENGINE COOLANT
2006 QX56
4. Install the Tool by installing the radiator cap adapter onto theradiator neck opening. Then attach the gauge body assembly
with the refill tube and the venturi assembly to the radiator cap
adapter.
5. Insert the refill hose into the coolant mixture container that is placed at floor level. Make sure the ball valve is in the closed
position.

Use Genuine NISSAN Long Life Anti-freeze coolant or equiv-
alent, mixed 50/50 with distilled water or demineralized water.
Refer to MA-12, "
ANTI-FREEZE COOLANT MIXTURE
RATIO" .
6. Install an air hose to the venturi assembly, the air pressure must be within specification.
CAUTION:
The compressed air supply must be equipped with an air
dryer.
7. The vacuum gauge will begin to rise and there will be an audible hissing noise. During this process open the ball valve on the refill hose slightly. Coolant will be visible ris-
ing in the refill hose. Once the refill hose is full of coolant, close the ball valve. This will purge any air
trapped in the refill hose.
8. Continue to draw the vacuum until the gauge reaches 28 inches of vacuum. The gauge may not reach 28 inches in high altitude
locations, refer to the vacuum specifications based on the alti-
tude above sea level.
9. When the vacuum gauge has reached the specified amount, disconnect the air hose and wait 20 seconds to see if the system loses any vacuum. If the vacuum level drops, perform any necessary repairs to the
system and repeat steps 6 - 8 to bring the vacuum to the specified amount. Recheck for any leaks.
10. Place the coolant container (with the refill hose inserted) at the same level as the top of the radiator. Then open the ball valve on the refill hose so the coolant will be drawn up to fill the cooling system. The cooling
system is full when the vacuum gauge reads zero.
CAUTION:
Do not allow the coolant container to get too low when filling, to avoid air from being drawn into
the cooling system.
11. Remove the Tool from the radiator neck opening and install the radiator cap.
12. Remove the non-vented reservoir cap.
13. Fill the cooling system reservoir tank to the specified level. Run the engine to warm up the cooling system and top up the system as necessary before installing the vented reservoir cap.
FLUSHING COOLING SYSTEM
1. Drain the water from the engine cooling system. Refer to CO-11, "DRAINING ENGINE COOLANT" .
2. Fill the radiator and the reservoir tank (to the “MAX ” line), with water. Reinstall the radiator cap and leave
the vented reservoir cap off.
3. Run the engine until it reaches normal operating temperature. Cooling system capacity
(with reservoir)
: Refer to
MA-11, "
Fluids
and Lubricants" .
Compressed air
supply pressure : 5.7 - 8.5 kPa (5.6 - 8.4 kg/cm
2 ,
80 - 120 psi)
LLIA0058E
Altitude above sea level Vacuum gauge reading
0 - 100 m (328 ft) : 28 inches of vacuum
300 m (984 ft) : 27 inches of vacuum
500 m (1,641 ft) : 26 inches of vacuum
1,000 m (3,281 ft) : 24 - 25 inches of vacuum
LLIA0057E

ENGINE COOLANTCO-13
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Revision: November 2009 2006 QX56
4. Press the engine accelerator two or three times under no-load.
5. Stop the engine and wait until it cools down.
6. Drain the water from the engine cooling system. Refer to CO-11, "
DRAINING ENGINE COOLANT" .
7. Repeat steps 2 through 6 until clear water begins to drain from the radiator.

CO-16Revision: November 2009
RADIATOR
2006 QX56
10. Lift up and remove the radiator.CAUTION:
Do not damage or scratch air conditioner condenser and
radiator core when removing.
INSTALLATION
Installation is in the reverse order of removal.
INSPECTION AFTER INSTALLATION

Check for leaks of 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 and A/T fluid.
Checking RadiatorEBS00REC
Check radiator for mud or clogging. If necessary, clean radiator as follows.
CAUTION:

Be careful not to bend or damage the radiator fins.

When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radi-
ator shroud and horns. Then tape the harness and electrical connectors to prevent water from
entering.
1. Apply water by hose to the back side of the radiator core vertically downward.
2. Apply water again to all radiator core surfaces.
3. Stop washing when dirt and debris no longer flow out from the radiator.
4. Blow air into the back side of radiator core vertically downward.

Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 30 cm (11.8
in).
5. Blow air again into all the radiator core surfaces until no water sprays out.
PBIC1536E

ENGINE COOLING FANCO-17
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Revision: November 2009 2006 QX56
ENGINE COOLING FANPFP:21140
Removal and Installation (Crankshaft Driven Type)EBS00RED
REMOVAL
1. Remove the air duct and resonator assembly. Refer to EM-15, "Removal and Installation" .
2. Remove the engine front undercover using power tool.
3. Remove the lower radiator shroud. Refer to CO-14, "
Removal and Installation" .
4. Remove the drive belt. Refer to EM-13, "
Removal and Installation" .
5. Remove the cooling fan.
INSPECTION AFTER REMOVAL
Fan Coupling
Inspect fan coupling for oil leakage and bimetal conditions.
Fan Bracket

Visually check that there is no significant looseness in the fan
bracket shaft, and that it turns smoothly by hand.

If there are any unusual concerns, replace the cooling fan pulley.
INSTALLATION
Installation is in the reverse order of removal.

Install cooling fan with its front mark “F” facing front of engine. Refer to CO-17, "Removal and Installation
(Crankshaft Driven Type)" .
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .
1. Cooling fan2. Fan coupling3. Fan bracket
4. Cooling fan pulley
WBIA0632E
SLC072
WBIA0418E

CO-18Revision: November 2009
ENGINE COOLING FAN
2006 QX56

Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
Removal and Installation (Motor Driven Type)EBS00REE
REMOVAL
1. Remove front bumper. Refer to EI-13, "Removal and Installation" .
2. Disconnect harness connector from fan motor.
3. Remove the bolt and remove the fan grille and motor assembly.
INSTALLATION
Installation is in the reverse order of removal.

Cooling fan is controlled by ECM. For details, refer to EC-473, "DTC P1217 ENGINE OVER TEMPERA-
TURE" .
WBIA0518E

CO-20Revision: November 2009
WATER PUMP
2006 QX56

After installation bleed the air from the cooling system. Refer to CO-11, "REFILLING ENGINE COOLANT"
.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up engine. Visually check for leaks of the engine coolant.

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

TROUBLE DIAGNOSISEC-91
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Revision: November 2009 2006 QX56
Fail-safe ChartUBS00L04
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected itemsEngine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START 40
°C (104 °F)
More than approx. 4 minutes after
ignition ON or START 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric throttle control actuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode
Engine speed will not rise more than 2,500 rpm due to the fuel cut