Mass air flow sensor INFINITI FX35 2008 Workshop Manual

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-285
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10. The 1st trip is detected, go to
EC-289, "
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 harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con- nector.
5. Select Service $03 with GST. Make sure DTC P0102 is detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine. If it is difficult to start engine, the fuel injection system has a mal-
function.
Perform the following procedure is advised.
a. Crank engine while depressing accelerator pedal.
b. If engine starts, go to EC-289, "
Diagnosis Procedure".
If engine does not start, remove ignition plugs and check for fouling, etc.
8. Keep engine at idle for at least 10 minutes.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to EC-289, "
Diagnosis Procedure".
If 1st trip DTC is not detected, per forming the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar condi tions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
11. Check 1st trip DTC.
12. The 1st trip is detected, go to EC-289, "
Diagnosis Procedure".
Engine coolant temperature (T)
conditionWhen the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
PBIB1565E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
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EC-290
< SERVICE INFORMATION >[VQ35DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK AIR FUEL RATIO (A/F) SE NSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
6. Also check harness for short to ground and 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-87, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-87, "
Fuel Pressure Check".
Bank 1A/F sensor 1 terminal ECM terminal
116
275
535
656
Bank 2 176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 116176
275277
535557
656658
Continuity should not exist.
PBIB2190E
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DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-291
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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-558
.)
 Fuel pressure regulator (Refer to EC-87, "
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
OK (With CONSULT-III)>>GO TO 7.
OK (Without CONSULT-III)>>GO TO 8.
NG >> Check connectors for rusted terminals or loose c onnections in the mass air flow sensor circuit or
ground. Refer to EC-175
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
OK or NG
OK >> GO TO 10.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-552
.
8.CHECK FUNCTION OF FUEL INJECTOR-I
Without CONSULT-III
1. Stop engine.
2. Disconnect harness connector F50, F251
3. Turn ignition switch ON. At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
PBIB2624E
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DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER
MISFIRE, NO. 1 - 6 CYLINDER MISFIRE
EC-313
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NG >> Follow the
EC-80, "Basic Inspection".
14.CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
6. Also check harness for short to power or short to ground.
OK or NG
OK >> GO TO 15.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
15.CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC-158, "
Component Inspection".
OK or NG
OK >> GO TO 16.
NG >> Replace malfunctioning air fuel ratio (A/F) sensor 1.
16.CHECK MASS AIR FLOW SENSOR
A/F sensor 1 terminal ECM terminal
Bank 1 116
275
535
656
Bank 2 176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 116176
275277
535557
656658
Continuity should not exist.
PBIB2093E
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EC-314
< SERVICE INFORMATION >[VQ35DE]
DTC P0300, P0301,
P0302, P0303, P0304, P0305, P0306 MULTIPLE CYLINDER
MISFIRE, NO. 1 - 6 CYLINDER MISFIRE
With CONSULT-III
Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-III.
With GST
Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 17.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-175
.
17.CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-96, "
Symptom Matrix Chart".
OK or NG
OK >> GO TO 18.
NG >> Repair or replace.
18.ERASE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memo ry after performing the tests. Refer to EC-55, "
Emission-Related
Diagnostic Information".
>> GO TO 19.
19.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
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DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-333
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Overall Function CheckINFOID:0000000001326159
Use this procedure to check the overall function of the th
ree way catalyst 1. During this check, a 1st trip DTC
might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Set voltmeter probes between ECM terminals 74 [HO2S2 (bank 1) signal], 55 [HO2S2 (bank 2) signal] and ground.
7. Keep engine speed at 2,500 rpm constant under no load.
8. Make sure that the voltage does not vary for more than 5 sec- onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to
EC-333, "
Diagnosis Procedure".
 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
Diagnosis ProcedureINFOID:0000000001326160
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst 1.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK IGNITION TIMING
Check the following items. Refer to EC-80, "
Basic Inspection".
PBIB1108E
PBIB1922E
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EC-348
< SERVICE INFORMATION >[VQ35DE]
DTC P0443 EVAP CANISTER PURGE VO
LUME CONTROL SOLENOID VALVE
DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VA LV E
DescriptionINFOID:0000000001326169
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control sol enoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/O FF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engi ne control. The optimum value stored in the ECM is
determined by considering various engine conditions. When t he engine is operating, the flow rate of fuel vapor
from the EVAP canister is r egulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326170
Specification data are reference values.
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1Density of oxygen in exhaust gas
(Mixture ratio fe
edback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor Vehicle speed*
2
SEF337U
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle
(Accelerator pedal is not depressed
even slightly, after engine starting)
0%
2,000 rpm —
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DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-355
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DTC P0444, P0445 EVAP CANISTER
PURGE VOLUME CONTROL SOLE-
NOID VALVE
DescriptionINFOID:0000000001326177
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/O FF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engi ne control. The optimum value stored in the ECM is
determined by considering various engine conditions. When t he engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326178
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor Vehicle speed*
2
SEF337U
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Idle
(Accelerator pedal is not depressed
even slightly, after engine starting)
0%
2,000 rpm —
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DTC P0506 ISC SYSTEMEC-409
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DTC P0506 ISC SYSTEM
DescriptionINFOID:0000000001326246
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 load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicINFOID:0000000001326247
DTC Confirmation ProcedureINFOID:0000000001326248
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-85, "
Idle Air Volume Learning",
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-593
.
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and run it for at least 1 minute at idle speed.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-409, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326249
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 registration of all IVIS(NATS) ignition key IDs.
Refer to BL-187, "
ECM Re-Communicating Function".
4. Perform EC-84, "
VIN Registration".
5. Perform EC-85, "
Accelerator Pedal Released Position Learning".
6. Perform EC-85, "
Throttle Valve Closed Position Learning".
7. Perform EC-85, "
Idle Air Volume Learning".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506 Idle speed control sys-
tem (ISC) RPM lower
than expected 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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DTC P0507 ISC SYSTEMEC-411
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DTC P0507 ISC SYSTEM
DescriptionINFOID:0000000001326250
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 load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicINFOID:0000000001326251
DTC Confirmation ProcedureINFOID:0000000001326252
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-85, "
Idle Air Volume Learning",
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-593
.
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and run it for at least 1 minute at idle speed.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-411, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326253
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.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507 Idle speed control sys-
tem (ISC) 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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