2008 INFINITI FX35 hot

CO-40
< SERVICE INFORMATION >[VK45DE]
RADIATOR
RADIATOR
ComponentINFOID:0000000001325871
Removal and InstallationINFOID:0000000001325872
REMOVAL
WARNING:
Do not remove radiator cap when engine is hot.
Serious burns could occur from high-pressure engine
coolant escaping from radiator. Wrap a thick cloth arou nd radiator cap. Slowly turn it a quarter of a
turn to release built-up pressure. Carefully remove radiator cap by turning it all the way.
1. Remove engine cover with power tool. Refer to EM-169, "
Component".
2. Remove engine front undercover with power tool.
3. Drain engine coolant from radiator. Refer to CO-37, "
Changing Engine Coolant".
CAUTION:
Perform this step when engine is cold.
4. Remove air duct (inlet), air cleaner case and mass air flow sensor assembly. Refer to EM-173, "
Compo-
nent".
5. Remove radiator hoses (upper and lower). CAUTION:
Do not spill engine coolant on drive belts.
1. Radiator 2. Upper mount bracket 3. Mounting rubber
4. Radiator hose (lower) 5. Radiator drain plug 6. O-ring
7. A/T fluid cooler hose 8. Radiator hose (upper) 9. Reservoir tank hose
10. Reservoir tank cap 11. Reservoir tank 12. Radiator shroud (lower)
13. Radiator shroud
PBIC1531E
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COMBINATION METERSDI-19
< SERVICE INFORMATION >
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Engine Coolant Temperature Signal InspectionINFOID:0000000001328447
Symptom: Water temperature gauge indication is malfunction.
1.CHECK COMBINATION METER INPUT SIGNAL
1. Connect CONSULT-III, and start engine.
2. Select “METER/M&A” on CONSULT-III.
3. Using “W TEMP METER” on “Data Monitor”, compare the value of “Data Monitor” with water temperature
gauge pointer of combination meter.
OK or NG
OK >> GO TO 2.
NG >> Replace combination meter.
2.CHECK UNIFIED METER AND A/C AMP. INPUT SIGNAL
Select “Data Monitor” of CONSULT-“COOLAN TEMP/S ” of “ENGINE” and “W TEMP METER” of “METER/
M&A”.
OK or NG
OK >> Perform self-diagnosis of ECM. Refer to EC-117, "CONSULT-III Function (ENGINE)" (VQ35DE)
or EC-695, "
CONSULT-III Function (ENGINE)" (VK45DE).
NG >> Replace unified meter and A/C amp. Refer to DI-32, "
Removal and Installation of Unified Meter
and A/C Amp".
Fuel Level Sensor Signal InspectionINFOID:0000000001328448
Symptom:
 Fuel gauge indication is malfunctioning.
 Low-fuel warning lamp indication is irregular.
NOTE:
The following symptoms are not malfunctions.
Fuel gauge Depending on vehicle posture or driving circumstance, the fuel level in the tank varies, and the pointer may
fluctuate.
 If the vehicle is fueled with the ignition switch ON, the pointer will move slowly.
Low-fuel warning lamp
 Depending on vehicle posture or driving circumstance, t he fuel in the tank flows and the warning lamp ON
timing may change.
1.CHECK COMBINATION METER INPUT SIGNAL
1. Select “METER A/C AMP” on CONSULT-III.
2. Using “FUEL METER” on “Data Monitor”, compare t he value of “Data Monitor” with fuel gauge pointer of
combination meter.
OK or NG
Water temperature gauge pointer Reference value of data monitor [ °C ( °F)]
Hot Approx. 130 (266)
Middle Approx. 70 - 105 (158 - 221) Cold Approx. 50 (122)
Fuel gauge pointer Reference value of data monitor [lit.] Full Approx. 86
Three quarters Approx. 70 Half Approx. 48
A quarter Approx. 25 Empty Approx. 9
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EC-32
< SERVICE INFORMATION >[VQ35DE]
ENGINE CONTROL SYSTEM
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is
determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated to improve engine performance under various operat-
ing conditions as listed below.
 During warm-up
 When starting the engine
 During acceleration
 Hot-engine operation
 When selector lever is changed from N to D
 High-load, high-speed operation
 During deceleration
 During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
Air conditioner switch Air conditioner operation*
2
Wheel sensorVehicle speed*2
PBIB3020E
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ENGINE CONTROL SYSTEMEC-33
< SERVICE INFORMATION > [VQ35DE]
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(A/F) sensor 1 in the exhaust manifold to monitor
whether the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about air fuel
ratio (A/F) sensor 1, refer to EC-220
. This maintains the mixture ratio within the range of stoichiometric (ideal
air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the thr ee way catalyst 1. Even if the switching characteris-
tics of air fuel ratio (A/F) sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from
heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
 Deceleration and acceleration
 High-load, high-speed operation
 Malfunction of air fuel ratio (A/F) sensor 1 or its circuit
 Insufficient activation of air fuel ratio (A /F) sensor 1 at low engine coolant temperature
 High engine coolant temperature
 During warm-up
 After shifting from N to D
 When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F)
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the bas ic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensati on used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 i ndicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical value. The signal then triggers a r eduction in fuel volume if the mixture ratio is rich, and
an increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation ca rried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycl e according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six fuel injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
SEF179U
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DTC P0101 MAF SENSOREC-175
< SERVICE INFORMATION > [VQ35DE]
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DTC P0101 MAF SENSOR
Component DescriptionINFOID:0000000001325989
The mass air flow (MAF) sensor is placed in the stream of intake air.
It measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sens
or controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001325990
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001325991
DTC Confirmation ProcedureINFOID:0000000001325992
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
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.
PROCEDURE FOR MALFUNCTION A
NOTE:
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-131
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Idle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0101
0101 Mass air flow sensor cir-
cuit range/performance A)
A high voltage from the sensor is sent to ECM
under light load driving condition.  Harness or connectors
(Mass air flow sensor circuit is
open or shorted.)
 Mass air flow sensor
 EVAP control system pressure
sensor
 Intake air temperature sensor
B) A low voltage from the sensor is sent to ECM un-
der heavy load driving condition.  Harness or connectors
(Mass air flow sensor circuit is
open or shorted.)
 Intake air leaks
 Mass air flow sensor
 EVAP control system pressure sensor
 Intake air temperature sensor
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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EC-182
< SERVICE INFORMATION >[VQ35DE]
DTC P0102, P0103 MAF SENSOR
DTC P0102, P0103 MAF SENSOR
Component DescriptionINFOID:0000000001325998
The mass air flow (MAF) sensor is placed in the stream of intake air.
It measures the intake flow rate
by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, electric current is supplied to hot wire is changed to main-
tain the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001325999
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326000
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001326001
NOTE:
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.
PROCEDURE FOR DTC P0102
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-131
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No.
Trouble diagnosis
name DTC detecting condition Possible cause
P0102
0102 Mass air flow sensor
circuit low input An excessively low voltage from the sensor is sent
to ECM.  Harness or connectors
(Mass air flow sensor circuit is open or short-
ed.)
 Intake air leaks
 Mass air flow sensor
P0103
0103 Mass air flow sensor
circuit high input An excessively high voltage from the sensor is
sent to ECM.  Harness or connectors
(Mass air flow sensor circuit is open or short-
ed.)
 Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will no t rise more than 2,400 rpm due to the fuel cut.
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DTC P0181 FTT SENSOREC-297
< SERVICE INFORMATION > [VQ35DE]
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5.CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “unified meter and A/C amp.” harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and “unified meter and
A/C amp.” terminal 36. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors B1, M11
 Harness for open or short between “fuel level sensor unit and fuel pump” and “unified meter and A/C amp.”
>> Repair open circuit or short to ground or short to power in harness or connector.
7.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-297, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace fuel level sensor unit.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326114
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 4 and 5 by heating with hot water as shown in the fig-
ure.
If NG, replace fuel level sensor unit.
Removal and InstallationINFOID:0000000001326115
FUEL TANK TEMPERATURE SENSOR
Refer to FL-4.
Continuity should exist.
Temperature
°C ( °F) Resistance k Ω
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
PBIB0931E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0182, P0183 FTT SENSOREC-301
< SERVICE INFORMATION > [VQ35DE]
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3. Check harness continuity between “fuel level sensor
unit and fuel pump” terminal 5 and “unified meter and
A/C amp.” terminal 36. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors B1, M11
 Harness for open or short between “fuel level sensor unit and fuel pump” and “unified meter and A/C amp.”
>> Repair open circuit or short to ground or short to power in harness or connector.
7.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-301, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace fuel level sensor unit.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326121
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 4 and 5 by heating with hot water as shown in the fig-
ure.
If NG, replace fuel level sensor unit.
Removal and InstallationINFOID:0000000001326122
FUEL TANK TEMPERATURE SENSOR
Refer to FL-4.
Continuity should exist.
Temperature
°C ( °F) Resistance k Ω
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
PBIB0931E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C