mass air flow sensor INFINITI FX35 2004 Service Manual

EC-1254
[VK45DE]
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Revision: 2004 November 2004 FX35/FX45
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)PFP:14956
DescriptionABS00CED
SYSTEM DESCRIPTION
*: The ECM determines the start signal status by the signals of engine speed and battery voltage.
When the engine is running at low or medium speed, the power valve is fully closed. Under this condition, the
effective suction port length is equivalent to the total length of the intake manifold collector's suction port
including the intake valve. This long suction port provides increased air intake which results in improved suc-
tion efficiency and higher torque generation.
The surge tank and one-way valve are provided. When engine is running at high speed, the ECM sends the
signal to the VIAS control solenoid valve. This signal introduces the intake manifold vacuum into the power
valve actuator and therefore opens the power valve to two suction passages together in the collector.
Under this condition, the effective port length is equivalent to the length of the suction port provided indepen-
dently for each cylinder. This shortened port length results in enhanced engine output with reduced suction
resistance under high speeds.
The power valve is always open regardless of the engine speed when gear position is in N or P.
Sensor Input signal to ECM ECM function Actuator
Mass air flow sensor Amount of intake air
VIAS control VIAS control solenoid valve Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
Engine coolant temperature sensor Engine coolant temperature
PBIB1876E

REFRIGERANT PRESSURE SENSOR
EC-1289
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureABS00CF2
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 PUSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B/WSensor ground
(Mass air flow sensor / IAT
sensor / Power steering
pressure sensor / EVAP
control system pressure
sensor / Refrigerant pres-
sure sensor / ECT sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
70 L/R Refrigerant pressure sensor[Engine is running]

Warm-up condition

Both A/C switch and blower switch are ON
(Compressor operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB1188E

EC-1336
[VK45DE]
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: 2004 November 2004 FX35/FX45
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureABS00CG2
Idle Speed and Ignition TimingABS00CG3
*1: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights, heater fan & rear window defogger)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueABS00CG4
Mass Air Flow SensorABS00CG5
*: Engine is warmed up to normal operating temperature and running under no-load.
Intake Air Temperature SensorABS00CG6
Engine Coolant Temperature SensorABS00CG7
Heated Oxygen Sensor 1 HeaterABS00CG8
Heated Oxygen Sensor 2 HeaterABS00CG9
Crankshaft Position Sensor (POS)ABS00CGA
Refer to EC-964, "Component Inspection" .
Camshaft Position Sensor (PHASE)ABS00CGB
Refer to EC-970, "Component Inspection" .
Throttle Control MotorABS00CGC
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed
No-load*1 (in P or N position)650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 12° ± 5° BTDC
Condition Calculated load value% (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle1.2 - 1.8V*
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g·m/sec at idle*
7.0 - 20.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.9 - 2.1
80 (176)0.31 - 0.37
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 3.3 - 4.0Ω
Resistance [at 25°C (77°F)] 5.0 - 7.0Ω
Resistance [at 25°C (77°F)] Approximately 1 - 15Ω

AIR CLEANER AND AIR DUCT
EM-17
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Revision: 2004 November 2004 FX35/FX45
AIR CLEANER AND AIR DUCTPFP:16500
Removal and InstallationABS004U0
REMOVAL
1. Remove engine cover with power tool. Refer to EM-19, "INTAKE MANIFOLD COLLECTOR" .

This work is unnecessary when parts located forward of mass air flow sensor are removed/installed.
2. Remove air duct (inlet).
3. Disconnect mass air flow sensor harness connector.
4. Disconnect PCV hose.
5. Remove air cleaner case/mass air flow sensor assembly and air duct/resonator assembly disconnecting
their joints.

Add marks as necessary for easier installation.
6. Remove mass air flow sensor from air cleaner case.
CAUTION:
Handle mass air flow sensor with care.

Do not shock it.

Do not disassemble it.

Do not touch its sensor.
7. Remove resonator in fender, lifting left fender protector.
INSTALLATION
Note to the following, and install in the reverse order of removal.
1. Air hose 2. PCV hose 3. Air duct
4. Air hose 5. Power duct 6. Clip
7. Air duct (inlet) 8. Resonator 9. Grommet
10. Air cleaner case 11. Air cleaner filter 12. Air cleaner case
13. O-ring 14. Mass air flow sensor
SBIA0462E

EM-18
[VQ35DE]
AIR CLEANER AND AIR DUCT
Revision: 2004 November 2004 FX35/FX45

Align marks. Attach each joint. Screw clamps firmly.

To position air cleaner case, refer to EM-18, "Changing Air Cleaner Filter" .
Changing Air Cleaner FilterABS004U1
INSPECTION
Check status (fouling, damage, etc.) of air cleaner filter at power duct
hole.
REMOVAL
Removal in the order below.
1. Remove air duct (inlet) from air cleaner case.
2. Disconnect harness connector from mass air flow sensor.
3. Loosen clamp bolts of air hose.
4. Remove mounting bolts for air cleaner case. Remove air cleaner
case/mass air flow sensor/air hose assembly.
5. Unclip and open air cleaner case, and remove air cleaner filter.
INSTALLATION
Note to the following, and install in the reverse order of removal.

If grommet at bottom of air cleaner case comes off together with
air cleaner case, fix it to vehicle before installation.

Look at internal bottom face through power duct hole, and posi-
tion air cleaner case with resonator upper end circle and air
cleaner case round hole aligned. Then push air cleaner case
straight down.

At this time, check by hand if protrusion at bottom of air cleaner
case has been inserted into grommet on vehicle side.

Clip power duct with bulge on reverse side of lower end
engaged with air cleaner case.
SBIA0463E
SBIA0464E
KBIA0954E

OIL PAN AND OIL STRAINER
EM-31
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Revision: 2004 November 2004 FX35/FX45
CAUTION:
Perform when engine is cold.
7. Remove engine cover with power tool. Refer to EM-19, "
INTAKE MANIFOLD COLLECTOR" .
8. Remove air hose from air duct to mass air flow sensor side and electric throttle control actuator side.
Refer to EM-17, "
AIR CLEANER AND AIR DUCT" .
9. Removal engine rear lower slinger, and install engine rear slinger to sling engine assembly for positioning.
Refer to EM-8, "
Special Service Tools" .
10. Remove front suspension member. Refer to FSU-17, "
FRONT SUSPENSION MEMBER" .
11. Remove drive belt for alternator and power steering pump and A/C compressor. Refer to EM-15, "
DRIVE
BELTS" .
12. Remove alternator stay. Refer to SC-23, "
CHARGING SYSTEM" .
13. Remove starter motor. Refer to SC-10, "
STARTING SYSTEM" .
14. Remove alternator and power steering pump and A/C compressor idler pulley and bracket assembly.
Refer to EM-15, "
DRIVE BELTS" .
15. Disconnect A/T fluid cooler hoses, and remove oil cooler water pipe mounting bolt. Refer to LU-14, "
OIL
COOLER" .
16. Disconnect A/T fluid cooler tube.
17. Remove crankshaft position sensor (POS).
CAUTION:

Handle carefully to avoid dropping and shocks.

Do not disassemble.

Do not allow metal powder to adhere to magnetic part at sensor tip.

Do not place sensors in a location where they are exposed to magnetism.
18. Remove oil filter, as necessary. Refer to LU-10, "
OIL FILTER" .
19. Remove oil cooler, as necessary. Refer to LU-14, "
OIL COOLER" .
20. Remove oil pan (lower) as the following:
a. Loosen bolts in reverse order as shown in the figure to remove.
b. Insert seal cutter (SST) between oil pan (upper) and oil pan
(lower).
c. Slide seal cutter by tapping on the side of tool with hammer.
Remove oil pan (lower).
CAUTION:

Be careful not to damage the mating surface.

Do not insert flat-bladed screwdriver, this will damage the
mating surface.
21. Remove oil strainer.Slinger bolts:
: 28.0 N·m (2.9 kg-m, 21 ft-lb)
PBIC0782E
SEM960F

OIL PAN AND OIL STRAINER
EM-37
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Revision: 2004 November 2004 FX35/FX45
8. Remove air hose from air duct to mass air flow sensor side and electric throttle control actuator side.
Refer to EM-17, "
AIR CLEANER AND AIR DUCT" .
9. Remove drive belt for alternator and power steering pump and A/C compressor. Refer to EM-15, "
DRIVE
BELTS" .
10. Remove front drive shaft (LH and RH) and side shaft. Refer to FA X - 1 2 , "
FRONT DRIVE SHAFT" .
11. Remove side shaft. Refer to FFD-10, "
FRONT FINAL DRIVE ASSEMBLY" .
12. Removal engine rear lower slinger, and install engine rear slinger to sling engine assembly for positioning.
Refer to EM-8, "
Special Service Tools" .
13. Remove front suspension member. Refer to Refer to FSU-17, "
FRONT SUSPENSION MEMBER" .
14. Remove engine mounting bracket, engine mounting bracket (lower) and insulator. Refer to EM-110,
"ENGINE ASSEMBLY" .
15. Remove front propeller shaft. Refer to PR-4, "
FRONT PROPELLER SHAFT" .
16. Remove oil filter and oil filter bracket. Refer to LU-12, "
OIL FILTER BRACKET (AWD)" .
17. Remove alternator stay. Refer to SC-23, "
CHARGING SYSTEM" .
18. Remove alternator and power steering pump and A/C compressor idler pulley and bracket. Refer to EM-
15, "DRIVE BELTS" .
19. Disconnect A/T fluid cooler hoses, and remove oil cooler water pipe mounting bolt. Refer to LU-14, "
OIL
COOLER" .
20. Disconnect A/T fluid cooler tube.
21. Remove front final drive assembly. Refer to FFD-10, "
FRONT FINAL DRIVE ASSEMBLY" .
22. Remove starter motor. Refer to SC-10, "
STARTING SYSTEM" .
23. Remove crankshaft position sensor (POS).
CAUTION:

Handle carefully to avoid dropping and shocks.

Do not disassemble.

Do not allow metal powder to adhere to magnetic part at sensor tip.

Do not place sensors in a location where they are exposed to magnetism.
24. Remove oil pan (lower) as the following:
a. Loosen bolts in reverse order as shown in the figure to remove.
b. Insert seal cutter (SST) between oil pan (upper) and oil pan
(lower).
c. Slide seal cutter by tapping on the side of tool with hammer.
Remove oil pan (lower).
CAUTION:

Be careful not to damage the mating surface.

Do not insert flat-bladed screwdriver, this will damage the
mating surface.Slinger bolts:
: 28.0 N·m (2.9 kg-m, 21 ft-lb)
PBIC0782E
SEM960F

EM-172
[VK45DE]
AIR CLEANER AND AIR DUCT
Revision: 2004 November 2004 FX35/FX45
AIR CLEANER AND AIR DUCTPFP:16500
Removal and InstallationABS006IB
REMOVAL
1. Remove engine cover with power tool. Refer to EM-168, "ENGINE ROOM COVER" .
2. Disconnect harness connector from mass air flow sensor.
3. Disconnect vacuum hose and PCV hose.
4. Remove air duct (inlet), air cleaner case and mass air flow sensor assembly, air duct and resonator
assembly disconnecting their joints.

Add marks as necessary for easier installation.
5. Remove mass air flow sensor from air cleaner case.
CAUTION:
Handle mass air flow sensor with following cares.

Do not shock it.

Do not disassemble it.

Do not touch its sensor.
INSTALLATION
Note to the following, and install in the reverse order of removal.
1. Air duct and resonator assembly 2. Bracket 3. Vacuum hose
4. Mass air flow sensor 5. O-ring 6. Air cleaner case
7. Air cleaner filter 8. Cover 9. Air cleaner case
10. Resonator 11. Mounting rubber 12. Air duct (inlet)
13. Clip
PBIC1657E

AIR CLEANER AND AIR DUCT
EM-173
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Revision: 2004 November 2004 FX35/FX45

Align marks. Attach each joint. Screw clamps firmly.
Changing Air Cleaner FilterABS00A2T
REMOVAL
1. Remove air duct (inlet), air cleaner case and mass air flow sensor assembly.
2. Remove air cleaner filter from air cleaner case.
INSTALLATION
Install in the reverse order of removal.

INTAKE MANIFOLD
EM-175
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Revision: 2004 November 2004 FX35/FX45
1. Remove engine cover with power tool. Refer to EM-168, "ENGINE ROOM COVER" .
2. Release fuel pressure. Refer to EC-700, "
FUEL PRESSURE RELEASE" .
3. Drain engine coolant. Refer to CO-36, "
Changing Engine Coolant" .
4. Remove air duct (inlet), air cleaner case and mass air flow sensor assembly, air duct and resonator
assembly. Refer to EM-172, "
AIR CLEANER AND AIR DUCT" .
5. Disconnect fuel feed hose quick connector on engine side.
Refer to EM-188, "
FUEL INJECTOR AND FUEL TUBE" .
6. Remove fuel damper and fuel hose assembly. Refer to EM-188, "
FUEL INJECTOR AND FUEL TUBE" .
CAUTION:

While hoses are disconnected, plug them to prevent fuel from draining.

Do not separate fuel damper and fuel hose.
7. Remove or disconnect harnesses, brackets, vacuum hose, vacuum gallery and PCV hose and tube from
intake manifold (upper).
8. Remove electric throttle control actuator as follows:
a. Disconnect harness connector.
b. Loosen mounting bolts diagonally.
CAUTION:

Handle carefully to avoid any shock to electric throttle control actuator.

Do not disassemble.
9. Disconnect water hoses from water gallery.
10. Remove intake manifold adaptor and water gallery.
11. Loosen bolts in reverse order as shown in the figure to remove
intake manifold (upper) with power tool.
12. Remove vacuum tank form intake manifold (lower).
13. Remove fuel injector and fuel tube assembly. Refer to EM-188, "
FUEL INJECTOR AND FUEL TUBE" .
14. Loosen bolts in reverse order as shown in the figure to remove
intake manifold (lower) with power tool.
SBIA0353E
PBIC0014E
PBIC0015E