Mass air flow sensor INFINITI FX35 2008 Service Manual

EC-994
< SERVICE INFORMATION >[VK45DE]
DTC P0506 ISC SYSTEM
DTC P0506 ISC SYSTEM
DescriptionINFOID:0000000001326843
NOTE:
If DTC P0506 is displayed with ot
her DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified leve l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine l oad (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagn osis LogicINFOID:0000000001326844
DTC Confirmation ProcedureINFOID:0000000001326845
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.
 If the target idle speed is out of the specified value, perform EC-663, "
Idle Air Volume Learning",
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-1196
.
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
 Always perform the test at a temperature above −10 °C(14 °F).
WITH CONSULT-III
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-994, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326846
1.CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2.REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS (NATS) system and regist ration of all IVIS (NATS) ignition key IDs. Refer to
BL-187, "
ECM Re-Communicating Function".
4. Perform EC-662, "
VIN Registration".
5. Perform EC-662, "
Accelerator Pedal Released Position Learning".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506 Idle speed control sys-
tem RPM lower than ex-
pected The idle speed is less than the target idle speed
by 100 rpm or more.
 Electric throttle control actuator
 Intake air leak
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EC-996
< SERVICE INFORMATION >[VK45DE]
DTC P0507 ISC SYSTEM
DTC P0507 ISC SYSTEM
DescriptionINFOID:0000000001326847
NOTE:
If DTC P0507 is displayed with ot
her DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified leve l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine l oad (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagn osis LogicINFOID:0000000001326848
DTC Confirmation ProcedureINFOID:0000000001326849
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.
 If the target idle speed is out of the specified value, perform EC-663, "
Idle Air Volume Learning",
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-1196
.
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
 Always perform the test at a temperature above −10 °C(14 °F).
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-996, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326850
1.CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Discover air leak location and repair.
3.REPLACE ECM
1. Stop engine.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507 Idle speed control sys-
tem RPM higher than
expected The idle speed is more than the target idle
speed by 200 rpm or more.  Electric throttle control actuator
 Intake air leak
 PCV system
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EC-1130
< SERVICE INFORMATION >[VK45DE]
DTC P2A00, P2A03 A/F SENSOR 1
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LE
ARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.
4. Clear the self-learning coef ficient by touching “CLEAR”.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
7. Let engine idle for 1 minute.
8. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to EC-1134, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor (1) harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min- utes.
11. Check 1st trip DTC.
12. If 1st trip DTC is detected, go to EC-1134, "
Diagnosis Procedure".
PBIB3230E
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DTC P2A00, P2A03 A/F SENSOR 1EC-1135
< SERVICE INFORMATION > [VK45DE]
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O>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “W ORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-633, "
Emission-related
Diagnostic Information".
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-861 or EC-871.
No >> GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water. Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
PBIB3230E
: Vehicle front 1. A/F sensor 1 (Bank 2)
harness connector2. A/F sensor 1 (Bank 1)
harness connector
Water should not exit.
PBIB3246E
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DTC P2A00, P2A03 A/F SENSOR 1EC-1137
< SERVICE INFORMATION > [VK45DE]
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5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK A/F SENSOR 1 HEATER
Refer to EC-744, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10.CHECK INTERMITTENT INCIDENT
Perform EC-717
.
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
11 .REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air f uel ratio (A/F) sensor 1.
CAUTION:
 Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
 Before installing new A/F senso r, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> GO TO 12.
12.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-III.
3. Make sure that “0.000” is displayed on CONSULT-III screen.
OK or NG
OK >> INSPECTION END
NG >> GO TO 13.
13.CLEAR THE SELF-LEARNING DATA.
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “W ORK SUPPORT” mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching “CLEAR”.
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-633, "
Emission-related
Diagnostic Information".
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
Continuity should not exist.
PBIB3230E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
EC-1187
< SERVICE INFORMATION > [VK45DE]
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VARIABLE INDUCTION AI
R CONTROL SYSTEM (VIAS)
DescriptionINFOID:0000000001327082
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 isfully closed. Under this condition, the
effective suction port length is equivalentto the total lengt h of the intake manifold collector's suction port includ-
ingthe intake valve. This long suction port provides incr eased air intake whichresults in improved suction effi-
ciency and higher torque generation.
The surge tank and one-way valve are provided. When engine is runningat high speed, the ECM sends the
signal to the VIAS control solenoid valve.This signal introduces the intake manifold vacuum into the power
valve actuatorand therefore opens the power valve to two suction passages together in thecollector.
Under this condition, the effective port length is equi valent to thelength of the suction port provided indepen-
dently for each cylinder. Thisshortened port length results in enhanced engine output with reduced suctionre-
sistance under high speeds.
The power valve is always open regardless of the engine speed when gear position is in N or P.
COMPONENT DESCRIPTION
Power Valve
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
VIAS control VIAS control solenoid valve
Mass air flow sensor Amount of intake air
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*
Engine coolant temperature sensor Engine coolant temperature
PBIB1876E
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EC-1196
< SERVICE INFORMATION >[VK45DE]
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel PressureINFOID:0000000001327089
Idle Speed and Ignition TimingINFOID:0000000001327090
*: 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 ValueINFOID:0000000001327091
Mass Air Flow SensorINFOID:0000000001327092
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorINFOID:0000000001327093
Engine Coolant Te
mperature SensorINFOID:0000000001327094
Fuel Tank Temperature SensorINFOID:0000000001327095
Fuel pressure at idling kPa (kg/cm2, psi) Approximately 350 (3.57, 51)
Target idle speed No load* (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-III or GST)
At idle 14.0 - 33.0
At 2,500 rpm 12.0 - 25.0
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.3V*
Mass air flow (Using CONSULT-III 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 k Ω
25 (77) 1.800 - 2.200
Temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Temperature °C ( °F) Resistance k Ω
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
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AIR CLEANER AND AIR DUCTEM-17
< SERVICE INFORMATION > [VQ35DE]
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AIR CLEANER AND AIR DUCT
ComponentINFOID:0000000001325707
Removal and InstallationINFOID:0000000001325708
REMOVAL
1. Remove engine cover with power tool. Refer to
EM-19, "Component".
 This work is unnecessary when parts located forward of mass air flow sensor are removed/installed.
2. Remove air duct (inlet) and power duct.
3. Disconnect mass air flow sensor harness connector.
4. Disconnect PCV hose.
5. Remove air cleaner case/mass air flow sensor and air duct 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 senso r with the following cares.
 Do not shock it.
 Do not disassemble it.
 Do not touch its sensor.
7. Remove resonator in fender, lifting left fender protector.
INSPECTION AFTER REMOVAL
Inspect air hoses for cracks or tear.
 If anything found replace air hose.
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
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EM-18
< SERVICE INFORMATION >[VQ35DE]
AIR CLEANER AND AIR DUCT
INSTALLATION
Note the following, and install in the reverse order of removal.
 Align marks. Attach each joint. Screw clamps firmly.
 To position air cleaner case, refer to
EM-18, "
Changing Air Cleaner Filter".
Changing Air Cleaner FilterINFOID:0000000001325709
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. Unhook clips and open air cleaner case, and remove air cleaner filter.
INSTALLATION
Note 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 position 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
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OIL PAN AND OIL STRAINEREM-31
< SERVICE INFORMATION > [VQ35DE]
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 Do not spill engine oil on drive belts.
6. Drain engine coolant. Refer to CO-10, "
Changing Engine Coolant".
CAUTION:
 Perform this step when the engine is cold.
 Do not spill engine coolant on drive belts.
7. Remove engine cover with power tool. Refer to EM-19, "
Component".
8. Remove air hose from air duct to mass air flow sens or side and electric throttle control actuator side.
Refer to EM-17, "
Component".
9. Removal engine rear lower slinger, and install engine rear slinger [SST: 10006 31U00 ( — )] to sling engine assembly for positioning. Refer to EM-7, "
Special Service Tool".
10. Remove front suspension member. Refer to FSU-16, "
Removal and Installation".
11. Remove drive belts. Refer to EM-15, "
Removal and Installation".
12. Remove alternator stay. Refer to SC-19, "
System Description".
13. Remove starter motor. Refer to SC-8, "
System Description".
14. Remove idler pulley and bracket assembly. Refer to EM-64, "
Component".
15. Disconnect oil cooler water hoses, and remove oil cooler water pipe mounting bolt. Refer to LU-12, "
Com-
ponent".
16. Disconnect A/T fluid cooler hoses, and remove A/T fluid cooler tube. Refer to AT-241, "
Removal and
Installation (2WD Models)".
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 wh ere they are exposed to magnetism.
18. Remove oil filter, as necessary. Refer to LU-8, "
Removal and Installation".
19. Remove oil cooler, as necessary. Refer to LU-12, "
Component".
20. Remove oil pan (lower) as follows:
a. Loosen mounting bolts in reverse order as shown in the figure to remove.
b. Insert the seal cutter (SST) between oil pan (upper) and oil pan (lower).
CAUTION:
 Be careful not to damage the mating surfaces.
 Do not insert a screwdriver, this will damage the mating
surfaces.
c. Slide the seal cutter by tapping on the side of tool with a ham- mer. Remove oil pan (lower).Slinger bolts:
: 28.0 N·m (2.9 kg-m, 21 ft-lb)
PBIC0782E
SEM960F
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