2008 INFINITI FX35 Mass air flow sensor

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 —
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-355
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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 —
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0506 ISC SYSTEMEC-409
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0507 ISC SYSTEMEC-411
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P2A00, P2A03 A/F SENSOR 1EC-533
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.
4. Clear the self-learning coefficient 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-537, "
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.
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. Select Service $07 with GST. If 1st trip DTC is detected, go to EC-537, "
Diagnosis Procedure".
PBIB1565E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P2A00, P2A03 A/F SENSOR 1EC-537
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000001326424
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-144, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1
Loosen and retighten the air fuel ratio (A/F) sensor 1.
>> 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.
TERMI- NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
24 L A/F sensor 1 heater
(bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
57 G A/F sensor 1 (bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 2.6V
58 Y Approximately 2.3V
76 P Approximately 3.1V
77 BR Approximately 2.3V
PBIB1584E
PBIB2625E
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
PBIB2200E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-538
< SERVICE INFORMATION >[VQ35DE]
DTC P2A00, P2A03 A/F SENSOR 1
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 “WORK 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 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-55, "
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-274 or EC-284.
No >> GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
3. Check harness connector for water. Water should not exit.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness connector.
6.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
PBIB1565E
PBIB2200E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P2A00, P2A03 A/F SENSOR 1EC-541
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
3. Disconnect mass air flow sensor 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-55, "
Emission-Related
Diagnostic Information".
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
14.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then 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.
>>INSPECTION END
Removal and InstallationINFOID:0000000001326425
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-26.
PBIB1565E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C