coolant temperature INFINITI QX56 2011 Factory Repair Manual

EC-496
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIV
E TEST” mode of “ECM” with CONSULT-III.
3. Set the Duty value to 100%.
4. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
CAUTION:
Wait for 1 minute or more to measure.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98 °C (209 °F).
2. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
CAUTION:
Wait for 1 minute or more to measure.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 5.
5.CHECK ELECTRICALLY-CONTROLLED COOL ING FAN COUPLING CONTROL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector.
3. Check the continuity between electrically-contro lled cooling fan coupling harness connector and IPDM E/
R harness connector.
4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 6.
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector Terminal
F39 3 Ground 2. 5 V
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector Terminal
F39 3 Ground 2. 5 V
JMMIA0404GB
JMMIA0404GB
+−
Continuity
Electrically-controlled cooling fan
coupling IPDM E/R
Connector Terminal Connector Terminal F39 3 E17 72 Existed
Revision: 2010 May2011 QX56

ENGINE CONTROL SYSTEM SYMPTOMSEC-525
< SYMPTOM DIAGNOSIS > [VK56VD]
C
D
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F
G H
I
J
K L
M A
EC
NP
O
Mass air flow sensor circuit
1
12 2
222 2 EC-201
Engine coolant temperature sensor circuit
333
EC-217
Air fuel ratio (A/F) sensor 1 circuit EC-181
EC-228
EC-232
EC-235
EC-238
Throttle position sensor circuit
22EC-219
EC-288
EC-406
EC-407
EC-475
Accelerator pedal position sensor circuit 3 2 1
EC-468EC-471
EC-478
Knock sensor circuit 2 3
EC-297
Engine oil temperature sensor 4 2 3EC-285
Crankshaft position sensor circuit 2 2EC-299
Camshaft position sensor circuit 3 2EC-303
Vehicle speed signal circuit 2 3 3 3EC-356
Power steering pressure sensor circuit 2 3 3EC-371
ECM 22333333333EC-376EC-378
EC-380
Intake valve timing control solenoid valve cir-
cuit
32 13223 3
EC-193
VVEL control module 3 4 4 3 EC-451EC-452
VVEL actuator motor 3 4 4 3
EC-390
VVEL actuator motor relay 3 4 4 3EC-393
VVEL control shaft position sensor 3 4 4 3EC-387
PNP signal circuit 3 3 3 3 3EC-383
Refrigerant pressure sensor circuit 2 3 3 4EC-520
Electrical load signal circuit 3EC-493
Air conditioner circuit 223333333 3 2HAC-60
ABS actuator and electric unit (control unit) 4BRC-60
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: 2010 May2011 QX56

E C -528
< SYMPTOM DIAGNOSIS >[VK56VD]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Lubrica-
tion
Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler 55555 55 5 EM-56
EM-60
LU-9
LU-12
LU-14
Oil level (Low)/Filthy oil
LU-7
Cooling
Radiator/Hose/Radiator filler cap
55555 55 45 CO-11
CO-11
Thermostat 5
CO-21
Water pumpCO-19
Water galleryEM-115
Cooling fan
5CO-17
Coolant level (Low)/Contaminat-
ed coolant
CO-8
IVIS (INFINITI Vehicle Immobilizer System —
NATS)11
SEC-48
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: 2010 May2011 QX56

EM-86
< REMOVAL AND INSTALLATION >
CYLINDER HEAD
CYLINDER HEAD
Exploded ViewINFOID:0000000006289571
CAUTION:
A high degree of precision is required for a valve on the intake side. Never remove the valve related
parts unless necessary.
1. Valve lifter (EXH) 2. Valve collet (EXH) 3. Valve spring retainer (EXH)
4. Valve oil seal (EXH) 5. Valve spring (with valve spring seat)
(EXH)6. Valve guide (EXH)
7. Spark plug 8. Valve lifter (INT) 9. Valve collet (INT)
10. Valve spring retainer (INT) 11. Valve oil seal (INT) 12. Valve spring (with valve spring seat)
(INT)
13. Cylinder head bolt 14. Cylinder head (bank 2) 15. Valve seat (EXH)
16. Valve (EXH) 17. Cylinder head gasket (bank 2) 18. Oil filter (for VVEL ladder assembly)
19. Cylinder block 20. Valve (INT) 21. Valve seat (INT)
22. Cylinder head gasket (bank 1) 23. Cylinder head (bank 1) 24. Engine coolant temperature sensor
A. Comply with the installation proce-
dure when tightening. Refer to
EM-
87, "Removal and Installation".
Refer to GI-4, "
Components" for symbol marks in the figure.
JPBIA3524GB
Revision: 2010 May2011 QX56

ABBREVIATIONSGI-15
< HOW TO USE THIS MANUAL >
C
DE
F
G H
I
J
K L
M B
GI
N
O P
E
F
G
H
ABBREVIATION DESCRIPTION E/T Exhaust temperature
EBD Electric brake force distribution EC Engine control
ECL Engine coolant level
ECM Engine control module ECT Engine coolant temperature
ECV Electrical control valve
EEPROM Electrically erasable programmable read only memory EFT Engine fuel temperature
EGR Exhaust gas recirculation
EGRT Exhaust gas recirculation temperature EGT Exhaust gas temperature
EOP Engine oil pressure EP Exhaust pressure
EPR Exhaust pressure regulator EPS Electronically controlled power steering
ESP Electronic stability program system
EVAP canister Evaporative emission canister EXC Exhaust control
ABBREVIATION DESCRIPTION FC Fan control
FCW Forward collision warning FIC Fuel injector controlFP Fuel pump
FR Front
FRP Fuel rail pressure FRT Fuel rail temperature
FTP Fuel tank pressure FTT Fuel tank temperature
ABBREVIATION DESCRIPTION GND GroundGPS Global positioning systemGST Generic scan tool
ABBREVIATION DESCRIPTION HBMC Hydraulic body-motion control systemHDD Hard disk drive
HO2S Heated oxygen sensor HOC Heated oxidation catalyst
Revision: 2010 May2011 QX56

HAC-6
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
FRONT AUTOMATIC AIR CONDITIONING SYSTEM
FRONT AUTOMATIC AIR CONDITIONING
SYSTEM : Component Parts Location
INFOID:0000000006275848
1. Preset switch 2. Engine coolant temperature sensor
Refer to EC-16, "
Component Parts
Location". 3. IPDM E/R
Refer to PCS-4, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location"
5. Refrigerant pressure sensor 6. Ambient sensor
7. Magnet clutch 8. AV control unit Refer to AV- 9 , "
Component Parts Lo-
cation". 9. Combination meter
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
10. Sunload sensor 11. Front display 12. Upper ventilator door motor
JMIIA0812ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSHAC-7
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
C
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K L
M A
B
HAC
N
O P
FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Component Description
INFOID:0000000006275849
13. Aspirator 14. Front air mix door motor (Driver side) 15. Intake sensor
16. Front mode door motor 17. Front air mix door motor (Passenger
side)18. Intake door motor
19. Front blower motor 20. A/C auto amp. 21. Front in-vehicle sensor
A. Left side of heater & cooling unit as- sembly B. Right side of heater & cooling unit as-
sembly C. Back side of blower unit assembly
D. Cluster lid C is removed E. Ins trument lower panel LH is re-
moved
Component Description
Ambient sensor Ambient sensor measures ambient air temperature. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
AV c o n t r o l u n i t AV control unit transmits front A/C control operation signal to A/C auto amp.
via CAN communication line.
A/C auto amp. A/C auto amp. controls front automatic air conditioning system by inputting
and calculating signals from each sensor and each switch. A/C auto amp.
has self-diagnosis function. Diagnosis of front automatic air conditioning
system can be performed quickly.
Blower unit Front blower motor Refer to
HAC-12
.
Intake door motor The LCU (Local Control Unit) is installed to intake door motor so as to per-
form the multiplex commu
nication control (LIN).
Refer to HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Combination meter Combination meter transmits vehicle speed signal to A/C auto amp. via
CAN communication line.
ECM ECM controls compressor according to status of engine and refrigerant.
ECM transmits engine coolant temperature signal to A/C auto amp. via
CAN communication line.
Engine coolant temperature sensor Engine coolant temperature sensor measures engine coolant temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Front display Front display indicates operation status of front automatic air conditioning
system.
Front in-vehicle sensor Front in-vehicle sensor measures temperature of intake air that flows
through aspirator to passenger room. The sensor uses a thermistor which
is sensitive to the change in temperature. The electrical resistance of the
thermistor decreases as temperature increases.
Revision: 2010 May2011 QX56

COMPONENT PARTSHAC-9
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
C
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M A
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HAC
N
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REAR AUTOMATIC AIR CONDITIONING SY STEM : Component Parts Location
INFOID:0000000006275850
1. Rear A/C control 2. Preset switch 3. Engine coolant temperature sensor
Refer to EC-16, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location". 5. Ambient sensor 6. AV control unit
Refer to AV- 9 , "
Component Parts Lo-
cation".
7. Combination meter Refer to MWI-6, "
METER SYSTEM :
Component Parts Location". 8. Sunload sensor 9. Front display
10. Rear mode door motor 11. Rear air mix door motor 12. Rear in-vehicle sensor
13. Rear blower motor 14. Rear A/C solenoid valve 15. Rear A/C relay
16. Intake sensor 17. A/C auto amp.
A. Right side of rear A/C unit assembly B. Left side of rear A/C unit assembly C. Back side of engine room (RH)
D. Left side of heater & cooling unit as- sembly E. Cluster lid C is removed
JMIIA0813ZZ
Revision: 2010 May2011 QX56

HAC-10
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
REAR AUTOMATIC AIR CONDITIONING SYSTEM : Component Description
INFOID:0000000006275851
ACCS (ADVANCED CLIMATE CONTROL SYSTEM)
Component Description
Ambient sensor Ambient sensor measures ambient air temperature. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
AV c o n t r o l u n i t AV control unit transmits front A/C control operation signal to A/C auto amp.
via CAN communication line.
A/C auto amp. A/C auto amp. controls rear automatic air conditioning system by inputting
and calculating signals from each sensor and each switch. A/C auto amp.
has self-diagnosis function. Diagnosis of rear automatic air conditioning
system can be performed quickly.
Combination meter Combination meter transmits vehicle speed signal to A/C auto amp. via
CAN communication line.
ECM ECM transmits engine coolant temperature signal to A/C auto amp. via
CAN communication line.
Engine coolant temperature sensor Engine coolant temperature sensor measures engine coolant temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Front display Front display indicates operation status of rear automatic air conditioning
system.
Heater & cooling unit
assembly Intake sensor Intake sensor measures temperature of front evaporator fin temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Preset switch Preset switch is integrated with front A/C control and AV operation switch.
Front A/C control operation signal is transmitted from preset switch to AV
control unit via communication line.
Rear A/C control The operation of the rear A/C control is communicated with the A/C auto
amp. via communication line.
Rear A/C relay Power is supplied to the rear A/C solenoid valve through rear A/C relay with
A/C auto amp. control.
Rear A/C unit assem-
bly Rear air mix door motor
The LCU (Local Contro
l Unit) is installed to rear air mix door motor so as to
perform the multiplex communication control (LIN).
Refer to HAC-26, "
REAR AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Rear A/C solenoid valve Rear A/C solenoid valve operates by power supply from rear A/C relay and
opens refrigerant line to rear evaporator.
Rear blower motor Refer to HAC-13
.
Rear in-vehicle sensor Rear in-vehicle sensor measures temperature of intake air that flows
through rear blower motor to passenger room. The sensor uses a ther-
mistor which is sensitive to the change in temperature. The electrical resis-
tance of the thermistor decreases as temperature increases.
Rear mode door motor The LCU (Local Control Unit) is installed to rear mode door motor so as to
perform the multiplex communication control (LIN).
Refer to
HAC-26, "
REAR AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Sunload sensor Sunload sensor measures sunload amount. This sensor is a dual system
so that sunload for driver side and passenger side are measured separate-
ly. This sensor converts sunload amount to voltage signal by photodiode
and transmits to A/C auto amp..
Revision: 2010 May2011 QX56

SYSTEMHAC-15
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
J
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M A
B
HAC
N
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- HAC-17, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Air Outlet Control"
-HAC-17, "FRONT AUTOMATIC AIR CONDITIONIN G SYSTEM : Compressor Control"
-HAC-18, "FRONT AUTOMATIC AIR CONDITION ING SYSTEM : Door Control"
-HAC-21, "FRONT AUTOMATIC AIR CONDITIONIN G SYSTEM : Temperature Control"
- Correction for input value of each sensor
Ambient sensor (setting temperature correction) A/C auto amp. controls passenger room temperature so that the optimum level always matches the temper-
ature level that passenger may feel. Correction is applied to the target temperature that is set using temper-
ature control dial, according to ambient temperature detected by ambient sensor.
Front in-vehicle sensor [in-vehicle temperature (front side) correction]
 Passenger room temperature (front side) detected by front in-vehicle sensor is corrected for each front air
conditioning control (driver side and passenger side)
Intake sensor (intake temperature correction)
 A/C auto amp. performs correction to change recognition intake temperature of A/C auto amp. quickly when
difference is large between recognition intake temperat ure and intake temperature detected by intake tem-
perature sensor. The correction is performed to change recognition intake temperature slowly when differ-
ence is small.
Sunload sensor (sunload amount correction) Sunload amount detected by sunload sensor is correc ted for each air conditioning control (driver side and
passenger side).
 A/C auto amp. performs correction to change recogni tion sunload amount of A/C auto amp. slowly when
sunload amount changes quickly, for exampl e when entering or exiting a tunnel.
Control by ECM
- Cooling fan control
Refer to EC-41, "
COOLING FAN CONTROL : System Description".
- Air conditioning cut control.
Refer to EC-47, "
AIR CONDITIONING CUT CONTRO L : System Description".
Control by IPDM E/R- Relay control
Refer to PCS-5, "
RELAY CONTROL SYSTEM : System Description".
- Cooling fan control
Refer to PCS-8, "
POWER CONTROL SYSTEM : System Description".
 Front A/C control (preset switch) transmits the co mmands for front automatic air conditioning system opera-
tion to AV control unit via communication line, then AV control unit transmits the commands to A/C auto amp.
via CAN communication. A/C auto amp. transmits each indication information to AV control unit via CAN
communication. AV control unit displays each indication information that is received.
FRONT AUTOMATIC AIR CONDITIONIN G SYSTEM : Air Flow ControlINFOID:0000000006275862
DESCRIPTION
 A/C auto amp. changes duty ratio of blower motor dr ive signal and controls air flow continuously. When air
flow is increased, duty ratio of front blower moto r control signal gradually increases to prevent a sudden
increase in air flow.
 In addition to manual control and automatic control, air flow control is consist of starting fan speed control,
low coolant temperature starting control, high in-vehi cle temperature starting control and fan speed control at
door motor operation
AUTOMATIC AIR FLOW CONTROL
 A/C auto amp. decides target air flow depending on target front air mix door opening angle.
 A/C auto amp. changes duty ratio of front blower moto r control signal and controls the air flow continuously
so that air flow matches to target air flow.
Revision: 2010 May2011 QX56