coolant temperature INFINITI QX56 2006 Factory Service Manual

ON BOARD DIAGNOSTIC (OBD) SYSTEMAT-39
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If the DTC is being detected currently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t ”.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to AT- 3 8 , "
ON BOARD DIAGNOSTIC (OBD) SYSTEM" .
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.

If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.

When you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-49, "
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS" .

Diagnostic trouble codes (DTC)

1st trip diagnostic trouble codes (1st trip DTC)

Freeze frame data
SAT015K
SAT016K
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data

AIR CONDITIONER CONTROLATC-25
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AIR CONDITIONER CONTROLPFP:27500
DescriptionEJS003X5
The front air control provides automatic regulation of the vehicle's interior temperature. The system is based
on the driver's and passenger's selected "set temperature", regardless of the outside temperature changes.
This is done by utilizing a microcomputer, also referred to as the front air control, which receives input signals
from the following seven sensors:

Ambient sensor

In-vehicle sensor

Intake sensor

Optical sensor (providing one input for driver and one input for passenger side)

PBR (Position Balanced Resistor)

Vehicle speed sensor (via CAN communication)

Engine coolant temperature (via CAN communication)
The front air control uses these signals (including the set temperature) to automatically control:

Outlet air volume

Air temperature

Air distribution
The front air control also provides separate regulation of the vehicle's interior temperature for the rear passen-
ger area. The system is based on the temperature and rear blower settings selected from rear control
switches located on the front air control, or from the temperature and rear blower settings selected from rear
control switches on the rear air control, when the front air control switches are set to the rear position.
The front air control is used to select:

Outlet air volume

Air temperature/distribution
OperationEJS003X6
AIR MIX DOORS CONTROL
The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
BLOWER SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
When AUTO switch is pressed, the blower motor starts to gradually increase air flow volume (if required).
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake door is automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and by the ON-OFF operation of the compressor.
MODE DOOR CONTROL
The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
DEFROSTER DOOR CONTROL
The defroster door is controlled by: Turning the defroster dial to front defroster.

ATC-94
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:

Front air control

Variable blower control

Front blower motor relay

Front blower motor

In-vehicle sensor

Ambient sensor

Optical sensor

Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the front air control and variable blower control
based on input from the in-vehicle sensor, optical sensor, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor speed is adjusted gradually to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
Starting Blower Speed Control
Start up from cold soak condition (Automatic mode).
In a cold start up condition where the engine coolant temperature is below 50°C (122 °F), the blower will not
operate at blower speed 1 for a short period of time (up to 210 seconds). The exact start delay time varies
depending on the ambient and engine coolant temperatures.
In the most extreme case (very low ambient temperature) the blower starting delay will be 210 seconds as
described above. After the coolant temperature reaches 50 °C (122 °F), or the 210 seconds has elapsed, the
blower speed will increase to the objective blower speed.
Start up from usual operating or hot soak condition (Automatic mode).
The blower will begin operation momentarily after the AUTO switch is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
WJIA1357E

ATC-132
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Water Valve CircuitEJS003Y1
COMPONENT DESCRIPTION
Water Valve
The water valve (1) cuts the flow of engine coolant to the front and
rear heater cores to allow for maximum cooling during A/C opera-
tion. It is controlled by the front air control.
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1. CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Disconnect water valve connector F68.
2. Turn ignition switch ON.
3. Rotate temperature control dial (driver) to 32 °C (90 °F).
4. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 1 and front air control harness connector M50 (B)
terminal 29.
4. Check continuity between water valve harness connector F68 (A) terminal 1 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
WJIA1791E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 1 2Rotate temperature
control dial Battery
voltage
WJIA1792E
1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
WJIA1793E

ENGINE COOLANTCO-11
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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. Refer to CO-12, "
FLUSHING 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-46, "
Recommended Chemical Products and Sealants" .
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.
3. Remove the vented reservoir cap and replace it with a non-vented reservoir cap before filling the cooling system.
WBIA0391E
PBIC0146E
WBIA0392E
Radiator drain plug : Refer to CO-14, "RADIATOR" .
RH cylinder block drain plug : Refer to EM-78, "
CYLINDER BLOCK" .

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

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
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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
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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