2008 INFINITI QX56 coolant temperature

GI-16
< HOW TO USE THIS MANUAL >
TERMINOLOGY
TERMINOLOGY
SAE J1930 Terminology ListINFOID:0000000001539196
All emission related terms used in this publication in accordance with SAE J1930 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
NEW TERMNEW ACRONYM /
ABBREVIATION OLD TERM
Air cleaner ACL Air cleaner
Barometric pressure BARO ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPSCrank angle sensor
Canister *** Canister
Carburetor CARBCarburetor
Charge air cooler CACIntercooler
Closed loop CLClosed loop
Closed throttle position switch CTP switchIdle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP***
Crankshaft position sensor CKPS***
Data link connector DLC***
Data link connector for CONSULT-III DLC for CONSULT-IIIDiagnostic connector for CONSULT-III
Diagnostic test mode DTMDiagnostic mode
Diagnostic test mode selector DTM selectorDiagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM IIMode II
Diagnostic trouble code DTCMalfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read
only memory EEPROM
***
Electronic ignition system EI systemIgnition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modification EM ***
Engine speed RPM Engine speed
Erasable programmable read only memory EPROM ***
Evaporative emission canister EVAP canister Canister
Evaporative emission system EVAP system Canister control solenoid valve
Exhaust gas recirculation valve EGR valve EGR valve
Revision: March 2010 2008 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-49
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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BLOWER MOTOR CONTROL SYSTEM
System DescriptionINFOID:0000000001679795
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:• A/C auto amp.
• A/C and AV switch assembly
• 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 calc ulated by the A/C auto amp. and variable blower control
based on input from the in-vehicle sensor, optical sens or, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor s peed is adjusted gradually to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automat ic 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 temper ature) 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).
AWIIA0173GB
Revision: March 2010 2008 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-51
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.PERFORM A/C AND AV SWITCH ASSEMBLY SELF-DIAGNOSIS
Perform self-diagnosis to check the A/C and AV switch assembly. Refer to HAC-22, "
A/C and AV Switch
Assembly Self-Diagnosis".
Is the inspection results normal?
YES >> GO TO 6.
NO >> Replace A/C and AV switch assembly. Refer to VTL-7, "
Removal and Installation".
6.CHECK BLOWER MOTOR OPERATION
Check and verify blower motor operates manually in all speeds.
Does blower motor operate in all speeds?
YES >> GO TO 7.
NO >> Refer to HAC-51, "
Front Blower Motor Diagnosis Procedure".
7.CHECK ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT
Check engine coolant temperature sensor circuit. Refer to EC-125, "
Diagnosis Procedure".
Is the inspection results normal?
YES >> GO TO 8.
NO >> Replace engine coolant temperature sensor.
8.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair" .
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
Front Blower Motor Diagnosis ProcedureINFOID:0000000001679797
SYMPTOM: Blower motor operation is malfunctioning.
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning under starting
blower speed control.
1.CHECK FUSES
AWIIA0174GB
Revision: March 2010 2008 QX56

HAC-76
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
WATER VALVE CIRCUIT
WATER VALVE CIRCUIT
DescriptionINFOID:0000000001679811
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 A/C auto amp.
Water Valve Diagnosis ProcedureINFOID:0000000001679812
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 18 °C (60° F).
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 2 and A/C auto amp. harness connector M50 (B)
terminal 46.
4. Check continuity between water valve harness connector F68 (A) terminal 2 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and Installation".
NO >> Repair harness or connector.
3.CHECK WATER VALVE POWER AND GROUND CIRCUITS
WJIA1791E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 2 1Rotate temperature
control dial Battery
voltage
WJIA1794E
2 - 46 : Continuity should exist.
2 - Ground : Continuity should not exist.
AWIIA0203ZZ
Revision: March 2010 2008 QX56

INSUFFICIENT HEATINGHAC-117
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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INSUFFICIENT HEATING
Component Function CheckINFOID:0000000001679835
SYMPTOM: Insufficient heating
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE INCREASE
1. Press the AUTO switch.
2. Turn the temperature control dial (driver) clockwise until 32 °C (90 °F) is displayed.
3. Check for hot air at discharge air outlets.
Can this symptom be duplicated?
YES >> GO TO 2.
NO >> Perform complete system operational check. Refer to HAC-4, "
Operational Check (Front)".
2.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 3.
3.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Is the inspection results normal?
YES >> GO TO 4.
NO >> Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
4.CHECK ENGINE COOLING SYSTEM
1. Check for proper engine coolant level. Refer to CO-10, "
Inspection".
2. Check hoses for leaks or kinks.
3. Check radiator cap. Refer to CO-10, "
Inspection".
4. Check for air in cooling system.
>> GO TO 5.
5.CHECK AIR MIX DOOR OPERATION
Check the operation of the air mix door.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Check the air mix door motor circuit. Refer to HAC-31, "
Air Mix Door Motor Component Function
Check".
6.CHECK AIR DUCTS
Check for disconnected or leaking air ducts.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair all disconnected or leaking air ducts.
7.CHECK HEATER HOSE TEMPERATURES
1. Start engine and warm it up to normal operating temperature.
2. Touch both the inlet and outlet heater hoses.
Is the inspection result normal?
YES >> Hot inlet hose and a warm outlet hose: GO TO 8.
NO >> • Inlet hose cold: GO TO 11. • Both hoses warm: GO TO 9.
8.CHECK ENGINE COOLANT SYSTEM
Check engine control temperature sensor. Refer to EC-126, "
Component Inspection".
Revision: March 2010 2008 QX56

HAC-118
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INSUFFICIENT HEATING
Is the inspection result normal?
YES >> System OK.
NO >> Repair or replace as necessary. Retest.
9.CHECK HEATER HOSES
Check heater hoses for proper installation.
Is the inspection result normal?
YES >> System OK.
NO >> 1. Back flush heater core. 2. Drain the water from the system.
3. Refill system with new engine coolant. Refer to CO-11, "
Changing Engine Coolant".
4. GO TO 10 to retest.
10.CHECK HEATER HOSE TEMPERATURES
1. Start engine and warm it up to normal operating temperature.
2. Touch both the inlet and outlet heater hoses.
Is the inspection result normal?
YES >> System OK.
NO >> Replace heater core. Refer to VTL-19, "
Removal and Installation".
11 .CHECK WATER VALVE
Check the operation of the water valve. Refer to HAC-76, "
Water Valve Diagnosis Procedure".
Is the inspection result normal?
YES >> System OK.
NO >> Replace water valve.
Revision: March 2010 2008 QX56

LAN-44
< FUNCTION DIAGNOSIS >[CAN]
CAN COMMUNICATION SYSTEM
FUNCTION DIAGNOSIS
CAN COMMUNICATION SYSTEM
CAN System Specification ChartINFOID:0000000001282400
Determine CAN system type from the following specificat
ion chart. Then choose the correct diagnosis sheet.
NOTE:
Refer to LAN-14, "
Trouble Diagnosis Procedure" for how to use CAN system specification chart.
×: Applicable
VEHICLE EQUIPMENT IDENTIFICATION INFORMATION
NOTE:
Check CAN system type from the vehicle shape and equipment.
CAN Communication Signal ChartINFOID:0000000001282401
Refer to LAN-13, "How to Use CAN Communication Signal Chart" for how to use CAN communication signal
chart.
NOTE:
Refer to LAN-36, "
Abbreviation List" for the abbreviations of the connecting units.
T: Transmit R: Receive
Body type Wagon
Axle 2WD4WD
Engine VK56DE
Transmission A/T
Brake control VDC
ICC system ××
CAN system type 1234
Diagnosis sheet LAN-40
LAN-41LAN-42LAN-43
AWMIA0012GB
Signal name/Connecting unitECM
TCM
LASER ICC
ADP
AV
BCM
HVAC I-KEY M&A
STRG 4WDABS
IPDM-E
Accelerator pedal position signal T RR R R
A/C compressor request signal T R
ASCD CRUISE lamp signal T R
ASCD OD cancel request signal T R
ASCD operation signal T R
ASCD SET lamp signal T R
Battery voltage signal T R
Closed throttle position signal T RR
Cooling fan speed request signal T R
Engine coolant temperature signal T RR
Revision: March 2010 2008 QX56

GENERAL MAINTENANCEMA-7
< ON-VEHICLE MAINTENANCE >
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UNDER THE HOOD AND VEHICLE
The maintenance items listed here should be checked periodically (e.g. each time you check the engine oil or refuel).
Seat beltsCheck that all parts of the seat belt system (e.g. buckles, anchors, adjusters and
retractors) operate properly and smoothly and are installed securely. Check the
belt webbing for cuts, fraying, wear or damage. SB-11, "Seat Belt Inspec-
tion", MA-33, "Checking
Seat Belts, Buckles, Re-
tractors, Anchors and
Adjusters"
Accelerator pedal
Check the pedal for smooth operation. Keep the floor mats away from the pedal. —
Brakes Check that the brake does not pull the vehicle to one side when applied. —
Brake pedal and
booster Check the pedal for smooth operation and make sure it has the proper distance
under it when depressed fully. Check the brake booster function. Keep the floor
mats away from the pedal. BR-15, "
Inspection and
Adjustment", BR-10, "In-
spection"
Parking brake
Check that the parking brake control has the proper travel and make sure that
the vehicle is held securely on a fairly steep hill when only the parking brake is
applied. PB-5, "On-Vehicle Ser-
vice"
Automatic transmis-
sion “Park” mecha-
nismOn a fairly steep hill check that the vehicle is held securely with the shift selector
in the P position without applying the brakes.
—
Item
Reference page
Item Reference page
Windshield washer
fluid Check that there is adequate fluid in the tank.
—
Engine coolant level Check the coolant level when the engine is cold. —
Radiator and hoses Check the front of the radiator and clean off any dirt, insects, leaves, etc., that
may have accumulated. Make sure the hoses have no cracks, deformation, de-
terioration or loose connections. —
Brake fluid level Make sure that the brake fluid level is between the “MAX” and “MIN” lines on the
reservoirs MA-29
Battery
Check the fluid level in each cell. It should be between the “MAX” and “MIN” lines.
Vehicles operated in high temperatures or under severe conditions require fre-
quent checks of the battery fluid level. —
Engine drive belt Make sure that no belt is frayed, worn, cracked or oily. MA-14
Engine oil levelCheck the level on the dipstick after parking the vehicle on a level spot and turn-
ing off the engine. —
Power steering fluid
level and lines Check the level on the reservoir with the engine off. Check the lines for improper
attachment, leaks, cracks, etc.
MA-31
Automatic transmis-
sion fluid levelCheck the level on the dipstick after putting the shift selector in “P” with the en-
gine idling.
MA-23
Exhaust system
Make sure there are no loose supports, cracks or holes. If the sound of the ex-
haust seems unusual or there is a smell of exhaust fumes, immediately locate
the trouble and correct it. MA-23
Underbody
The underbody is frequently exposed to corrosive substances such as those
used on icy roads or to control dust. It is very important to remove these sub-
stances, otherwise rust will form on the floor pan, frame, fuel lines and around the
exhaust system. At the end of winter, the underbody should be thoroughly
flushed with plain water, being careful to clean those areas where mud and dirt
can easily accumulate. —
Fluid leaks Check under the vehicle for fuel, oil, water or other fluid leaks after the vehicle
has been parked for a while. Water dripping from the air conditioner after use is
normal. If you should notice any leaks or gasoline fumes are evident, check for
the cause and correct it immediately. —
Revision: March 2010
2008 QX56