2008 INFINITI FX35 Mass air flow sensor

EC-136
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
OK >>
INSPECTION END
NG >> GO TO 15.
15.DISCONNECT AND RECONNE CT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of power steering, alternat or, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/F UEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-137
< SERVICE INFORMATION > [VQ35DE]
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2. Disconnect mass air flow sensor harness connecto
r. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-182
.
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace ma ss air flow sensor, and then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs.
Refer to BL-187, "
ECM Re-Communicating Function".
3. Perform EC-84, "
VIN Registration".
4. Perform EC-85, "
Accelerator Pedal Released Position Learning".
5. Perform EC-85, "
Throttle Valve Closed Position Learning".
6. Perform EC-85, "
Idle Air Volume Learning".
>> GO TO 29.
25.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
OK or NG
OK >> GO TO 27.
NG >> Repair or replace malfunctioning part, and then GO TO 26.
26.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” m ode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (Less than the SP value)>>GO TO 27.
27.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 28.
NG (Less than the SP value)>>Replace ma ss air flow sensor, and then GO TO 30.
28.CHECK INTAKE SYSTEM
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EC-138
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
 Disconnection, looseness, and cracks in air duct
 Looseness of oil filler cap
 Disconnection of oil level gauge
 Open stuck, breakage, hose disconnecti
on, or cracks of PCV valve
 Disconnection or cracks of EVAP purge hose, open stuc k of EVAP canister purge volume control solenoid
valve
 Malfunctioning seal of rocker cover gasket
 Disconnection, looseness, or cracks of hoses, such as vacuum hose, connecting to intake air system parts
 Malfunctioning seal of intake air system, etc.
>> GO TO 30.
29.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/F UEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
30.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITO R” mode, and then make sure that the indication is
within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-153
< SERVICE INFORMATION > [VQ35DE]
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000001325965
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the air fuel
ratio (A/F) sensor 1 heater corresponding to the engine
operating condition to keep the temperature of air fuel ratio (A/F) sensor 1 element at the specified range.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001325966
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001325967
DTC Confirmation ProcedureINFOID:0000000001325968
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.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-157, "
Diagnosis Procedure".
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater control Air fuel ratio (A/F) sensor 1 heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR(B1)
A/F S1 HTR(B2)  Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit low The current amperage in the heated air fuel ratio (A/
F) sensor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
[Air fuel ratio (A/F) sensor 1 heater cir-
cuit is open or shorted.]
 Air fuel ratio (A/F) sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the heated air fuel ratio (A/
F) sensor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
[Air fuel ratio (A/F) sensor 1 heater cir-
cuit is shorted.]
 Air fuel ratio (A/F) sensor 1 heater
P0052
0052
(Bank 2)
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EC-160
< SERVICE INFORMATION >[VQ35DE]
DTC P0037, P
0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000001325973
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001325974
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001325975
DTC Confirmation ProcedureINFOID:0000000001325976
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.
TESTING CONDITION:
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600 OFF
Below 3,600 rpm after the following conditions are met.
 Engine: After warming up
 Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at idle for 1 minute under no load ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)  Engine speed: Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load ON
 Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0037
0037
(Bank 1) Heated oxygen
sensor 2 heater
control circuit low The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(Heated oxygen sensor 2 heater circuit is
open or shorted.)
 Heated oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen
sensor 2 heater
control circuit high The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(Heated oxygen sensor 2 heater circuit is
shorted.)
 Heated oxygen sensor 2 heater
P0058
0058
(Bank 2)
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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
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EC-176
< SERVICE INFORMATION >[VQ35DE]
DTC P0101 MAF SENSOR
If engine will not start or stops soon, wait at leas
t 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
1. Start engine and warm it up to normal operating temperature.
2. Run engine for at least 10 seconds at idle speed.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-178, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-178, "
Diagnosis Procedure".
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
4. Increases engine speed to about 4,000 rpm.
5. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-178, "
Diagnosis Procedure".
If OK, go to following step.
6. Maintain the following conditions for at least 10 consecutive sec- onds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-178, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000001325993
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-178, "
Diagnosis Procedure".
ENG SPEED More than 2,000 rpm
TP SEN 1-B1 More than 3V
TP SEN 2-B1 More than 3V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB3457E
SEF534P
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EC-178
< SERVICE INFORMATION >[VQ35DE]
DTC P0101 MAF SENSOR
Diagnosis Procedure
INFOID:0000000001325995
1.INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A>>GO TO 3.
B>>GO TO 2.
2.CHECK INTAKE SYSTEM
Check the following for connection.
 Air duct
 Vacuum hoses
 Intake air passage between air duct and intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
3.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 4.
NG >> Repair or replace ground connections.
TER- MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
51 L/W Mass air flow sensor [Engine is running]

Warm-up condition
 Idle speed 1.0 - 1.2V
[Engine is running]
 Warm-up condition
 Engine speed: 2,500 rpm 1.6 - 2.0V
67 B/W Sensor ground [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]
 For a few seconds after turning ignition
switch OFF 0 - 1.5V
[Ignition switch: OFF]
 More than a few seconds after turning igni- tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 9
120 R
R/B
Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
PBIB2625E
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