fuel pump INFINITI QX56 2008 Factory Service Manual
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![INFINITI QX56 2008 Factory Service Manual AV
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001696149
AUDIO SYSTEM
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001696149
AUDIO SYSTEM
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001696149
AUDIO SYSTEM
The majority of the audio troubles are the result of outside causes (bad CD, electromagnetic interference,
etc.).
Noise
The following noise results from variations in field strength, such as fading noise and multi-path noise, or
external noise from trains and other sources. It is not a malfunction.
• Fading noise: This noise occurs because of variations in the field strength in a narrow range due to moun-
tains or buildings blocking the signal.
• Multi-path noise: This noise results from the waves sent directly from the broadcast station arriving at the antenna at a different time from the waves which reflect off mountains or buildings.
The vehicle itself can be a source of noise if noise prevention parts or electrical equipment is malfunctioning.
Check if noise is caused and/or changed by engine speed, ignition switch turned to each position, and opera-
tion of each piece of electrical equipment, and determine the cause.
NOTE:
The source of the noise can be found easily by listening to the noise while removing the fuses of electrical
components, one by one.
Type of Noise and Possible Cause
NAVIGATION SYSTEM
Basic Operation
Vehicle Mark
Occurrence condition Possible cause
Occurs only when engine is ON. A continuous growling noise occurs. The speed of
the noise varies with changes in the engine speed. • Ignition components
The occurrence of the noise is linked with the operation of the fuel pump. • Fuel pump condenser
Noise only occurs when various
electrical components are oper-
ating. A cracking or snapping sound occurs with the op-
eration of various switches.
• Relay malfunction, audio unit malfunction
The noise occurs when various motors are operat-
ing. • Motor case ground
•Motor
The noise occurs constantly, not just under certain conditions. • Rear defogger coil malfunction
• Open circuit in printed heater
• Poor ground of antenna feeder line
A cracking or snapping sound occurs while the vehicle is being driven, especially when
it is vibrating excessively. • Ground wire of body parts
• Ground due to improper part installation
• Wiring connections or a short circuit
Symptom
Cause Remedy
No image is shown. Display brightness adjustment is set fully to DARK
side. Adjust the display brightness.
No guide sound is heard.
Audio guide volume is too low or
too high. Volume control is set to OFF, MIN or MAX. Adjust the audio guide volume.
Audio guidance is not available while the vehicle is
driving on a dark pink route.
System is not malfunctioning.
Screen is too dark.
Motion of the image is too slow. Temperature inside the vehicle is low.
Wait until the temperature inside the vehicle
reaches the proper temperature.
Small black or bright spots appear
on the screen. Symptom peculiar to a liquid crystal display (dis-
play unit). System is not malfunction.
Revision: March 2010
2008 QX56
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EC-6
Component Description .........................................359
On Board Diagnosis Logic .....................................359
DTC Confirmation Procedure ................................359
Diagnosis Procedure .............................................360
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
362
Description ........................................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................365
P2118 THROTTLE CONTROL MOTOR ..........366
Component Description ....................................... ..366
On Board Diagnosis Logic .....................................366
DTC Confirmation Procedure ................................366
Diagnosis Procedure .............................................366
Component Inspection ...........................................367
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
368
Component Description ....................................... ..368
On Board Diagnosis Logic .....................................368
DTC Confirmation Procedure ................................368
Diagnosis Procedure .............................................369
P2122, P2123 APP SENSOR ..........................370
Component Description ....................................... ..370
On Board Diagnosis Logic .....................................370
DTC Confirmation Procedure ................................370
Diagnosis Procedure .............................................371
Component Inspection ...........................................372
P2127, P2128 APP SENSOR ..........................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................373
Component Inspection ...........................................376
P2135 TP SENSOR .........................................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................377
Component Inspection ...........................................380
P2138 APP SENSOR ......................................381
Component Description ....................................... ..381
On Board Diagnosis Logic .....................................381
DTC Confirmation Procedure ................................381
Diagnosis Procedure .............................................382
Component Inspection ...........................................384
P2A00, P2A03 A/F SENSOR 1 .......................385
Component Description ....................................... ..385
On Board Diagnosis Logic .....................................385
DTC Confirmation Procedure ................................385
Diagnosis Procedure .............................................386
ASCD BRAKE SWITCH ...................................390
Component Description ....................................... .390
Diagnosis Procedure .............................................390
Component Inspection ..........................................393
ASCD INDICATOR ...........................................394
Component Description ....................................... .394
Diagnosis Procedure .............................................394
COOLING FAN .................................................395
Diagnosis Procedure ............................................ .395
Component Inspection ..........................................395
ELECTRICAL LOAD SIGNAL ..........................397
Description ........................................................... .397
Diagnosis Procedure .............................................397
FUEL INJECTOR ..............................................399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................401
FUEL PUMP .....................................................402
Description ........................................................... .402
Diagnosis Procedure .............................................402
Component Inspection ..........................................405
ICC BRAKE SWITCH ..................................... ..406
Component Description ....................................... .406
Diagnosis Procedure .............................................406
Component Inspection ..........................................409
IGNITION SIGNAL ............................................411
Component Description ....................................... .411
Diagnosis Procedure .............................................411
Component Inspection ..........................................414
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
416
System Description .............................................. .416
Diagnosis Procedure .............................................416
Component Inspection ..........................................418
POSITIVE CRANKCASE VENTILATION .........421
Description ........................................................... .421
Component Inspection ..........................................421
REFRIGERANT PRESSURE SENSOR ...........423
Component Description ....................................... .423
Diagnosis Procedure .............................................423
ECU DIAGNOSIS ......................................426
ECM ................................................................ ..426
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
426
ECM Harness Connector Terminal Layout ...........429
ECM Terminal and Reference Value ....................429
Wiring Diagram - ENGINE CONTROL SYSTEM - .439
Fail-Safe Chart ......................................................459
DTC Inspection Priority Chart ...............................461
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EC-7
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DTC Index ...........................................................
..
462
Emission-related Diagnostic Information ...............466
SYMPTOM DIAGNOSIS ..... .......................481
ENGINE CONTROL SYSTEM SYMPTOMS .. ..481
Symptom Matrix Chart ........................................ ..481
NORMAL OPERATING CONDITION ...............485
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. ..
485
PRECAUTION ............................................486
PRECAUTIONS .............................................. ..486
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
486
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ..
486
On Board Diagnosis (OBD) System of Engine and
A/T .........................................................................
487
Precaution .............................................................487
PREPARATION .........................................491
PREPARATION .............................................. ..491
Special Service Tool ........................................... ..491
Commercial Service Tool ......................................492
ON-VEHICLE MAINTENANCE ..................494
FUEL PRESSURE .......................................... ..494
Fuel Pressure Check .............................................494
EVAP LEAK CHECK ......................................496
How to Detect Fuel Vapor Leakage ..................... ..496
ON-VEHICLE REPAIR ...............................498
EVAP CANISTER ............................................498
Component Inspection ......................................... ..498
Removal and Installation .......................................498
INTAKE VALVE TIMING CONTROL ..............500
Intake Valve Timing Control Solenoid Valve (LH) ..500
Intake Valve Timing Cont rol Solenoid Valve (RH) ..500
Intake Valve Timing Control Position Sensor (LH) ..501
Intake Valve Timing Control Position Sensor (RH) ..501
Camshaft Position Sensor (PHASE) .....................501
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... .
503
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
503
Fuel Pressure ...................................................... ..503
Idle Speed and Ignition Timing ..............................503
Calculated Load Value ..........................................503
Mass Air Flow Sensor ............................................503
Intake Air Temperature Sensor .............................503
Engine Coolant Temperature Sensor ....................503
A/F Sensor 1 Heater ..............................................503
Heated Oxygen sensor 2 Heater ...........................504
Crankshaft Position Sensor (POS) ........................504
Camshaft Position Sensor (PHASE) .....................504
Throttle Control Motor ............................................504
Fuel Injector ...........................................................504
Fuel Pump .............................................................504
Revision: March 2010 2008 QX56
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*1: This item includes 1st trip DTCs.
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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 COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value
Revision: March 2010
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PURG VOL C/V [%]
• Indicates the EVAP canister purge vol-
ume control solenoid valve control val INFINITI QX56 2008 Factory Service Manual ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
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PURG VOL C/V [%]
• Indicates the EVAP canister purge vol-
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
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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]
ו The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF] ו 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] ו Indicates the throttle control motor relay
control condition determined by the ECM
according to the input signals.
COOLING FAN
[HI/OFF] ו 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] ו Indicates the engine speed computed
from the input speed sensor signal.
VEHICLE SPEED
[km/h] or [mph] ו 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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NOTE:
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
ALT DUTY SIG
[ON/OFF] • The control condition of the power gener-
ation voltage variable control (deter-
mined by ECM according to the input
signals) is indicated.
ON: Power generation voltage variable
control is active.
OFF: Power generation voltage variable
control is inactive.
A/F ADJ-B1 • Indicates the correction factor stored in
ECM. The factor is calculated from the
difference between the target air/fuel ra-
tio stored in ECM and the air-fuel ratio
calculated from air fuel ratio (A/F) sensor
1 signal.
A/F ADJ-B2
Voltage [V]
• Voltage, frequency, duty cycle or pulse width measured by the probe. • Only # is displayed if item is unable to
be measured.
• Figures with #s are temporary ones. They are the same figures as an actual
piece of data which was just previously
measured.
Frequency [msec],
[Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOW Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description
Remarks
TEST ITEMCONDITION JUDGEMENTCHECK 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
Revision: March 2010
2008 QX56
Page 1377 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-78
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximat
ely 1 minute because they may fluctuate. It is NG
if the indic INFINITI QX56 2008 Factory Service Manual EC-78
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximat
ely 1 minute because they may fluctuate. It is NG
if the indic](/img/42/57030/w960_57030-1376.png)
EC-78
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximat
ely 1 minute because they may fluctuate. It is NG
if the indication is out of the SP value even a little.
OK or NG
OK >> GO TO 17.
NG (Less than the SP value)>>GO TO 2.
NG (More than the SP value)>>GO TO 3.
2.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 4.
NG (More than the SP value)>>GO TO 19.
3.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 6.
NG (More than the SP value)>>GO TO 6.
NG (Less than the SP value)>>GO TO 25.
4.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Stop the engine.
2. Disconnect PCV hose, and then plug it.
3. Start engine.
4. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> GO TO 5.
NG >> GO TO 6.
5.CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil. NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>>INSPECTION END
6.CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-494, "
Fuel Pressure Check" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-494, "
Fuel Pressure Check" .
GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7.DETECT MALFUNCTIONING PART
1. Check the following.
- Clogged and bent fuel hose and fuel tube
- Clogged fuel filter
- Fuel pump and its circuit (Refer to EC-494, "
Fuel Pressure Check" .)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-494, "
Fuel Pressure Check" .)
If OK, replace fuel pressure regulator.
Revision: March 2010 2008 QX56
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![INFINITI QX56 2008 Factory Service Manual P0116 ECT SENSOREC-121
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P0116 ECT SENSOR
Component DescriptionINFOID:0000000003760274
The engine coolant temperature sensor is used to d INFINITI QX56 2008 Factory Service Manual P0116 ECT SENSOREC-121
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P0116 ECT SENSOR
Component DescriptionINFOID:0000000003760274
The engine coolant temperature sensor is used to d](/img/42/57030/w960_57030-1419.png)
P0116 ECT SENSOREC-121
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P0116 ECT SENSOR
Component DescriptionINFOID:0000000003760274
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor
modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003760275
DTC Confirmation ProcedureINFOID:0000000003760276
NOTE:
•If DTC P0116 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-125, "
DTC Confirmation Procedure".
• If DTC confirmation procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, do not fill with the fuel.
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than10 minutes.
3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.
4. Check resistance between “fuel level sensor and fuel pump” terminals 3 and 4.
5. Soak the vehicle until the resistance between “fuel level sensor and fuel pump” terminals 3 and 4
becomes 0.5 k Ω higher than the value measured before soaking.
CAUTION:
Never turn ignition switch ON during the soaking time.
NOTE:
SEF594K
Engine coolant
temperature °C ( °F) Voltage* V
Resistance kΩ
− 10 (14) 4.47.0 - 11.4
20 (68) 3.52.1 - 2.9
50 (122) 2.20.68 - 1.00
90 (194) 0.90.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0116
0116 Engine coolant tempera-
ture sensor circuit range/
performance Engine coolant temperature signal from engine
coolant temperature sensor does not fluctuate,
even when some time has passed after starting
the engine with pre-warming up condition. • Harness or connectors
(High or low resistance in the circuit)
• Engine coolant temperature sensor
Revision: March 2010 2008 QX56
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![INFINITI QX56 2008 Factory Service Manual EC-180
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harnes INFINITI QX56 2008 Factory Service Manual EC-180
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harnes](/img/42/57030/w960_57030-1478.png)
EC-180
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-494, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Fuel pump and circuit (Refer to EC-402, "
Diagnosis Procedure".)
• Fuel pressure regulator (Refer to EC-494, "
Fuel Pressure Check".)
• Fuel lines
• Fuel filter for clogging
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
A/F sensor 1 terminal ECM terminal
Bank 1 13
5
25 6
Bank 2 11
6
27 5
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 13 511 6
25 627 5
Continuity should not exist.
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
Revision: March 2010 2008 QX56
Page 1485 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-186
< COMPONENT DIAGNOSIS >[VK56DE]
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harnes INFINITI QX56 2008 Factory Service Manual EC-186
< COMPONENT DIAGNOSIS >[VK56DE]
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harnes](/img/42/57030/w960_57030-1484.png)
EC-186
< COMPONENT DIAGNOSIS >[VK56DE]
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-494, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Fuel pump and circuit (Refer to EC-402, "
Diagnosis Procedure".)
• Fuel pressure regulator (Refer to EC-494, "
Fuel Pressure Check".)
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
A/F sensor 1 terminal ECM terminal
Bank 1 13
5
25 6
Bank 2 11
6
27 5
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 13 511 6
25 627 5
Continuity should not exist.
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
Revision: March 2010 2008 QX56