sensor INFINITI FX35 2008 Service Manual

DTC P0101 MAF SENSOREC-761
< SERVICE INFORMATION > [VK45DE]
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DTC P0101 MAF SENSOR
Component DescriptionINFOID:0000000001326586
The mass air flow sensor is placed in
the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor c ontrols 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:0000000001326587
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326588
DTC Confirmation ProcedureINFOID:0000000001326589
Perform PROCEDURE FOR MALFUNCTION A first.
If 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-709
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
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
(The 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
(The 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-762
< SERVICE INFORMATION >[VK45DE]
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-764, "
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-764, "
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-764, "
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-764, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000001326590
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overa ll function of the mass air flow sensor circuit. During this check, a 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 s ensor 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-764, "
Diagnosis Procedure".
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 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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DTC P0101 MAF SENSOREC-763
< SERVICE INFORMATION > [VK45DE]
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Wiring DiagramINFOID:0000000001326591
Specification data are reference values
and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
TBWM1327E
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EC-764
< SERVICE INFORMATION >[VK45DE]
DTC P0101 MAF SENSOR
Diagnosis Procedure
INFOID:0000000001326592
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 three ground screws on the body. Refer to EC-723, "
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 - 1.3V
[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)
PBIB2195E
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DTC P0101 MAF SENSOREC-765
< SERVICE INFORMATION > [VK45DE]
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4.CHECK MAF SENSOR PO
WER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor (1) harness connector.
2. Turn ignition switch ON.
3. Check voltage between MAF sensor terminal 2 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E211, M41
 Harness connectors M82, F102
 Harness for open or short between mass air flow sensor and ECM
 Harness for open or short between mass air flow sensor and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK MAF SENSOR GROUND CI RCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB3230E
Voltage: Battery voltage
PBIB1168E
Continuity should exist.
Continuity should exist.
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EC-766
< SERVICE INFORMATION >[VK45DE]
DTC P0101 MAF SENSOR
8.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-778, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9.CHECK EVAP CONTROL SY STEM PRESSURE SENSOR
Refer to EC-958, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK MASS AIR FLOW SENSOR
Refer to EC-766, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-717
.
>> INSPECTION END
Component InspectionINFOID:0000000001326593
MASS AIR FLOW SENSOR
With CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check i ndication under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.  Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system parts
b. If NG, repair or replace malfunc tioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.6 - 2.0
Idle to about 4,000 rpm 1.0 - 1.3 to Approx. 2.4*
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DTC P0101 MAF SENSOREC-767
< SERVICE INFORMATION > [VK45DE]
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Without CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
4. If the voltage is out of spec ification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.  Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 and 3 again. If OK, go to next step.
5. Turn ignition switch OFF.
6. Disconnect mass air flow sensor har ness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and InstallationINFOID:0000000001326594
MASS AIR FLOW SENSOR
Refer to EM-173.
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.6 - 2.0
Idle to about 4,000 rpm 1.0 - 1.3 to Approx. 2.4*
PBIB1106E
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EC-768
< SERVICE INFORMATION >[VK45DE]
DTC P0102, P0103 MAF SENSOR
DTC P0102, P0103 MAF SENSOR
Component DescriptionINFOID:0000000001326595
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor 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 Value in Data Monitor ModeINFOID:0000000001326596
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326597
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001326598
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 DTC P0102
1. Start engine and wait at least 5 seconds.
2. Check DTC.
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-709
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
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
P0102
0102 Mass air flow sensor
circuit low input An excessively low voltage from the sensor is sent
to ECM.  Harness or connectors
(The sensor circuit is open or shorted.)
 Intake air leaks
 Mass air flow sensor
P0103
0103 Mass air flow sensor
circuit high input An excessively high voltage from the sensor is
sent to ECM.  Harness or connectors
(The sensor circuit is open or shorted.)
 Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will no t rise more than 2,400 rpm due to the fuel cut.
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DTC P0102, P0103 MAF SENSOREC-769
< SERVICE INFORMATION > [VK45DE]
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3. If DTC is detected, go to
EC-771, "Diagnosis Procedure".
PROCEDURE FOR DTC P0103
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
3. If DTC is detected, go to EC-771, "
Diagnosis Procedure".
If DTC is not detected, go to next step.
4. Start engine and wait at least 5 seconds.
5. Check DTC.
6. If DTC is detected, go to EC-771, "
Diagnosis Procedure".
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EC-770
< SERVICE INFORMATION >[VK45DE]
DTC P0102, P0103 MAF SENSOR
Wiring Diagram
INFOID:0000000001326599
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
TBWM1327E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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