2009 INFINITI QX56 cooling

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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
VK56DE
BASIC INSPECTION ....... .............................
8
DIAGNOSIS AND REPAIR WORKFLOW ..... .....8
Trouble Diagnosis Introduction ........................... ......8
INSPECTION AND ADJUSTMENT ....................13
Basic Inspection .................................................. ....13
Idle Speed and Ignition Timing Check ....................17
Procedure After Replacing ECM .............................17
VIN Registration ......................................................17
Accelerator Pedal Released Position Learning .......18
Throttle Valve Closed Position Learning .................18
Idle Air Volume Learning .........................................18
FUNCTION DIAGNOSIS ..............................21
ENGINE CONTROL SYSTEM ........................ ....21
System Diagram .................................................. ....21
Engine Control Component Parts Location .............22
MULTIPORT FUEL INJECTION SYSTEM .........28
System Description ............................................. ....28
ELECTRIC IGNITION SYSTEM ..................... ....31
System Description ............................................. ....31
AIR CONDITIONING CUT CONTROL ...............32
Input/Output Signal Chart .................................... ....32
System Description .................................................32
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
33
System Description ............................................. ....33
Component Description ...........................................34
CAN COMMUNICATION ....................................35
System Description ............................................. ....35
COOLING FAN CONTROL ................................36
Description .......................................................... ....36
EVAPORATIVE EMISSION SYSTEM ...............37
Description ........................................................... ....37
INTAKE VALVE TIMING CONTROL ................40
Description ...............................................................40
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....41
Introduction ..............................................................41
Two Trip Detection Logic .........................................41
Emission-related Diagnostic Information .................42
Malfunction Indicator Lamp (MIL) ............................55
OBD System Operation Chart .................................58
CONSULT-III Function (ENGINE) ...........................63
Generic Scan Tool (GST) Function .........................72
COMPONENT DIAGNOSIS .........................74
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
74
Description ........................................................... ....74
Testing Condition .....................................................74
Inspection Procedure ...............................................74
Diagnosis Procedure ...............................................75
POWER SUPPLY AND GROUND CIRCUIT ....82
Diagnosis Procedure ...............................................82
Ground Inspection ...................................................85
U1000, U1001 CAN COMM CIRCUIT ...............86
Description ...............................................................86
On Board Diagnosis Logic .......................................86
DTC Confirmation Procedure ..................................86
Diagnosis Procedure ...............................................86
P0011, P0021 IVT CONTROL ...........................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................88
Component Inspection .............................................92
P0031, P0032, P0051, P0052 A/F SENSOR 1
HEATER ............................................................
94
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EC-6
On Board Diagnosis Logic .....................................351
DTC Confirmation Procedure ................................351
Diagnosis Procedure .............................................351
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
354
Description ........................................................... ..354
On Board Diagnosis Logic .....................................354
DTC Confirmation Procedure ................................354
Diagnosis Procedure .............................................354
Component Inspection ...........................................357
P2118 THROTTLE CONTROL MOTOR ..........358
Component Description ....................................... ..358
On Board Diagnosis Logic .....................................358
DTC Confirmation Procedure ................................358
Diagnosis Procedure .............................................358
Component Inspection ...........................................359
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
360
Component Description ....................................... ..360
On Board Diagnosis Logic .....................................360
DTC Confirmation Procedure ................................360
Diagnosis Procedure .............................................361
P2122, P2123 APP SENSOR ..........................362
Component Description ....................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................364
P2127, P2128 APP SENSOR ..........................365
Component Description ....................................... ..365
On Board Diagnosis Logic .....................................365
DTC Confirmation Procedure ................................365
Diagnosis Procedure .............................................365
Component Inspection ...........................................368
P2135 TP SENSOR .........................................369
Component Description ....................................... ..369
On Board Diagnosis Logic .....................................369
DTC Confirmation Procedure ................................369
Diagnosis Procedure .............................................369
Component Inspection ...........................................372
P2138 APP SENSOR ......................................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................374
Component Inspection ...........................................376
P2A00, P2A03 A/F SENSOR 1 .......................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................378
ASCD BRAKE SWITCH ................................. .383
Component Description ....................................... .383
Diagnosis Procedure .............................................383
Component Inspection ..........................................386
ASCD INDICATOR ...........................................387
Component Description ....................................... .387
Diagnosis Procedure .............................................387
COOLING FAN .................................................388
Diagnosis Procedure ............................................ .388
Component Inspection ..........................................388
ELECTRICAL LOAD SIGNAL ..........................390
Description ........................................................... .390
Diagnosis Procedure .............................................390
FUEL INJECTOR ..............................................392
Component Description ....................................... .392
Diagnosis Procedure .............................................392
Component Inspection ..........................................394
FUEL PUMP .....................................................395
Description ........................................................... .395
Diagnosis Procedure .............................................395
Component Inspection ..........................................398
ICC BRAKE SWITCH ..................................... ..399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................402
IGNITION SIGNAL ............................................404
Component Description ....................................... .404
Diagnosis Procedure .............................................404
Component Inspection ..........................................407
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
409
System Description .............................................. .409
Diagnosis Procedure .............................................409
Component Inspection ..........................................411
POSITIVE CRANKCASE VENTILATION .........414
Description ........................................................... .414
Component Inspection ..........................................414
REFRIGERANT PRESSURE SENSOR ...........416
Component Description ....................................... .416
Diagnosis Procedure .............................................416
ECU DIAGNOSIS ......................................419
ECM ................................................................ ..419
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
419
ECM Harness Connector Terminal Layout ...........422
ECM Terminal and Reference Value ....................422
Wiring Diagram - ENGINE CONTROL SYSTEM - .432
Fail-Safe Chart ......................................................453
DTC Inspection Priority Chart ...............................455
DTC Index .............................................................456
Emission-related Diagnostic Information ..............460
Revision: December 20092009 QX56

EC-22
< FUNCTION DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM
Engine Control Comp onent Parts Location
INFOID:0000000003771302
1. ECM 2. Battery current sensor 3. Power steering pressure sensor
4. Ignition coil (with power transistor)
and spark plug (bank 2) 5. Refrigerant pressure sensor 6. Intake valve timing control position
sensor (bank 2)
7. Intake valve timing control solenoid valve (bank 2) 8. Engine coolant temperature sensor 9. Electric throttle control actuator
10. Intake valve timing control position sensor (bank 1) 11. Intake valve timing control solenoid
valve (bank 1) 12. Cooling fan motor
13. Camshaft position sensor (PHASE) 14. I gnition coil (with power transistor)
and spark plug (bank 1) 15. Mass air flow sensor (with intake air
temperature sensor)
16. A/F sensor 1 (bank 1) 17. EVAP service port 18. Fuel injector (bank 1)
19. Knock sensor (bank 1) 20. EVAP canister purge volume control solenoid valve21. Knock sensor (bank 2)
22. Fuel injector (bank 2) 23. A/F sensor 1 (bank 2) 24. IPDM E/R
BBIA0743E
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EC-24
< FUNCTION DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM
10. Camshaft position sensor (PHASE) 11
. Electric throttle control actuator
(view with intake air duct removed) 12. Cooling fan motor harness connec-
tor
: Vehicle front
BBIA0739E
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EC-36
< FUNCTION DIAGNOSIS >[VK56DE]
COOLING FAN CONTROL
COOLING FAN CONTROL
DescriptionINFOID:0000000003771310
SYSTEM DESCRIPTION
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the
vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The c ontrol system has 2-step control [HI/OFF].
Cooling Fan Operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
Cooling fan
controlIPDM E/R
(Cooling fan relay)
Battery
Battery voltage*
1
Wheel sensorVehicle speed*2
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switchAir conditioner ON signal*
2
Refrigerant pressure sensor Refrigerant pressure
PBIB2060E
Revision: December 20092009 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-65
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X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-III screen in freeze frame
data
mode only if a 1st trip DTC or DTC is detected. For details, refer to "Freeze Frame Data and 1st Trip Freeze Frame Data".
*3: Always “CMPLT ” is displayed.
WORK SUPPORT MODE
Work Item
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector ××
Power transistor (Ignition timing) ××
Throttle contro l motor relay ××
Throttle control motor ×
EVAP canister purge volume con-
trol solenoid valve ××××
Air conditioner relay ×
Fuel pump relay ×××
Cooling fan relay ×××
Air fuel ratio (A/F) sensor 1 heater ×××*3
Heated oxygen sensor 2 heater ×××*3
EVAP canister vent control valve ×× ××
Intake valve timing control solenoid
valve ×××
Alternator ××
Calculated load value ××
Item
DIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK SUP-
PORT
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE  FUEL PUMP WILL STOP BY TOUCHING “START” DUR- ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
IDLE AIR VOL LEARN  THE IDLE AIR VOLUME THAT KEEPS THE ENGINE WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT  THE COEFFICI ENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
< FUNCTION DIAGNOSIS > [VK56DE]
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PURG VOL C/V [%]
 Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.
 The opening becomes larger as the val- ue increases.
INT/V TIM (B1)
[ ° CA]
 Indicates [°CA] of intake camshaft ad-
vanced angle.
INT/V TIM (B2)
[ ° CA]
INT/V SOL (B1) [%]  The control value of the intake valve tim- ing control solenoid valve (determined by
ECM according to the input signals) is in-
dicated.
 The advance angle becomes larger as
the value increases.
INT/V SOL (B2) [%]
AIR COND RLY
[ON/OFF]
 The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF]  Indicates the fuel pump relay control con-
dition determined by ECM according to
the input signals.
VENT CONT/V
[ON/OFF]  The control condition of the EVAP canis-
ter vent control valve (determined by
ECM according to the input signals) is in-
dicated.
ON: Closed
OFF: Open
THRTL RELAY [ON/
OFF] × Indicates the throttle control motor relay
control condition determined by the ECM
according to the input signals.
COOLING FAN
[HI/OFF] × The control condition of the cooling fan
(determined by ECM according to the in-
put signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF]  Indicates [ON/OFF] condition of heated
oxygen sensor 2 heater determined by
ECM according to the input signals.
HO2S2 HTR (B2)
[ON/OFF]
I/P PULLY SPD
[rpm]  Indicates the engine speed computed
from the input speed sensor signal.
VEHICLE SPEED
[km/h] or [mph]  Indicates the vehicle speed computed
from the output speed sensor signal.
IDL A/V LEARN
[YET/CMPLT]  Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has al-
ready been performed successfully.
TRVL AFTER MIL
[km] or [mile]  Distance traveled while MIL is activated.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-71
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*: Leaving cooling fan OFF with CONSULT-III while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to
EC-456, "DTC Index".
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION  Engine: Return to the original
trouble condition
 Change the amount of fuel injec-
tion using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Harness and connectors
 Fuel injector
 Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING  Engine: Return to the original
trouble condition
 Timing light: Set
 Retard the ignition timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Perform Idle Air Volume Learning.
POWER BAL-
ANCE  Engine: After warming up, idle the
engine.
 A/C switch: OFF
 Selector lever: P or N
 Cut off each injector signal one at a time using CONSULT-III. Engine runs rough or dies.
 Harness and connectors
 Compression
 Fuel injector
 Power transistor
Spark plug
 Ignition coil
COOLING FAN*  Ignition switch: ON
 Turn the cooling fan HI and OFF
using CONSULT-III. Cooling fan moves and stops.  Harness and connectors
 Cooling fan motor
IPDM E/R
ENG COOLANT
TEMP  Engine: Return to the original
trouble condition
 Change the engine coolant tem- perature using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.  Harness and connectors
 Engine coolant temperature sen-
sor
 Fuel injector
FUEL PUMP RE-
LAY  Ignition switch: ON
(Engine stopped)
 Turn the fuel pump relay ON and OFF using CONSULT-III and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
 Harness and connectors
 Fuel pump relay
PURG VOL
CONT/V  Engine: After warming up, run en-
gine at 1,500 rpm.
 Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
 Harness and connectors
 Solenoid valve
FUEL/T TEMP
SEN  Change the fuel tank temperature using CONSULT-III.
VENT CON-
TROL/V  Ignition switch: ON
(Engine stopped)
 Turn solenoid valve ON and OFF with the CONSULT-III and listen
to operating sound. Solenoid valve makes an operating
sound.
 Harness and connectors
 Solenoid valve
V/T ASSIGN AN-
GLE  Engine: Return to the original
trouble condition
 Change intake valve timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Harness and connectors
 Intake valve timing control sole-
noid valve
ALTERNATOR
DUTY  Engine: Idle
 Change duty ratio using CON-
SULT-III. Battery voltage changes.  Harness and connectors
IPDM E/R
 Alternator
Revision: December 20092009 QX56