2007 INFINITI QX56 cooling

CO-10
< SERVICE INFORMATION >
ENGINE COOLANT
• Wrap a thick cloth around the cap to carefully remove the cap. First, turn the cap a quarter of a turn
to release any built-up pressure, then push down and turn the cap all the way to remove it.
DRAINING ENGINE COOLANT
1. Turn ignition switch ON and set temperature control lever all the way to HOT position or the highest tem-
perature position. Wait 10 seconds and turn ignition switch OFF.
2. Remove the engine front undercover using power tool.
3. Open the radiator drain plug at the bottom of the radiator, and
remove the radiator filler cap. This is the only step required
when partially draining the cooling system (radiator only).
CAUTION:
Do not to allow the coolant to contact the drive belts.
4. When draining all of the coolant in the system for engine
removal or repair, it is necessary to drain the cylinder block.
Remove the RH cylinder block drain plug to drain the right bank
and the oil cooler hose to drain the left bank as shown.
5. Remove the reservoir tank to drain the engine coolant, then clean the reservoir tank before installing it.
6. Check the drained coolant for contaminants such as rust, corrosion or discoloration.
If the coolant is contaminated, flush the engine cooling system.
REFILLING ENGINE COOLANT
1. Close the radiator drain plug. Install the reservoir tank, cylinder block drain plug, and the oil cooler hose, if
removed for a total system drain or for engine removal or repair.
• The radiator must be completely empty of coolant and water.
• Apply sealant to the threads of the cylinder block drain plug. Use Genuine High Performance Thread
Sealant or equivalent. Refer to GI-45, "
Recommended Chemical Product and Sealant".
2. Set the vehicle heater controls to the full HOT and heater ON position. Turn the vehicle ignition ON with
the engine OFF as necessary to activate the heater mode.
WBIA0391E
PBIC0146E
WBIA0392E
Radiator drain plug : Refer to CO-13, "Removal and Installation".
RH cylinder block drain plug : Refer to EM-78
.

ENGINE COOLANT
CO-11
< SERVICE INFORMATION >
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3. Remove the vented reservoir cap and replace it with a non-vented reservoir cap before filling the cooling
system.
4. Install the Tool by installing the radiator cap adapter onto the
radiator 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 recommended NISSAN Long Life Anti-freeze coolant or
equivalent. Refer to MA-10, "
SAE Viscosity Number".
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 rising 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
Tool number : KV991J0070 (J-45695)
Cooling system capacity
(with reservoir): Refer to MA-10, "
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

CO-12
< SERVICE INFORMATION >
ENGINE COOLANT
1. Drain the water from the engine cooling system.
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.
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.
7. Repeat steps 2 through 6 until clear water begins to drain from the radiator.

RADIATOR
CO-15
< SERVICE INFORMATION >
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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-9, "Inspection".
• Start and warm up the engine. Visually check for leaks of the engine coolant and A/T fluid.
Checking RadiatorINFOID:0000000003531572
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, radia-
tor shroud and horns. Then tape the harness and electrical connectors to prevent water from enter-
ing.
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/cm
2, 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

CO-16
< SERVICE INFORMATION >
ENGINE COOLING FAN
ENGINE COOLING FAN
Removal and Installation (Crankshaft Driven Type)INFOID:0000000003531573
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-13, "
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.
INSPECTION AFTER INSTALLATION
• Check for leaks of the engine coolant. Refer to CO-9, "Inspection".
1. Cooling fan 2. Fan coupling 3. Fan bracket
4. Cooling fan pulley A. Front mark⇐Engine front
AWBIA0087GB
SLC072
WBIA0418E

ENGINE COOLING FAN
CO-17
< SERVICE INFORMATION >
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• Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
Removal and Installation (Motor Driven Type)INFOID:0000000003531574
REMOVAL
1. Remove front bumper. Refer to EI-12, "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-469
.
WBIA0793E

CO-18
< SERVICE INFORMATION >
WATER PUMP
WATER PUMP
Removal and InstallationINFOID:0000000003531575
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 CO-9,
"Changing 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-15, "
Removal and Installation".
4. Remove the drive belt. Refer to EM-13, "
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 rust 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.
• Replace the water pump, if necessary.
INSTALLATION
Installation is in the reverse order of removal.
• After installation bleed the air from the cooling system. Refer to CO-9, "
Changing Engine Coolant".
INSPECTION AFTER INSTALLATION
KBIA2543E
1. Gasket 2. Water pump 3. Water pump pulley
KBIA2552E

TROUBLE DIAGNOSIS
EC-89
< SERVICE INFORMATION >
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• 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 items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine 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.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON
or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 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
P2135Throttle 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
P2103Throttle 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
functionECM 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 ac-
tuator(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
P2138Accelerator pedal position
sensorThe 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