mass air flow sensor INFINITI FX35 2004 Owners Manual

EC-836
[VK45DE]
DTC P0102, P0103 MAF SENSOR
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS00C1I
MASS AIR FLOW SENSOR
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 specification, proceed the following.

Turn ignition switch OFF.

Disconnect mass air flow sensor harness connector and reconnect it again.

Perform steps 2 and 3 again.
5. If NG, remove mass air flow sensor from air duct. Check hot film for damage or dust.
6. If NG, clean or replace mass air flow sensor.
Removal and InstallationABS00C1J
MASS AIR FLOW SENSOR
Refer to EM-172, "AIR CLEANER AND AIR DUCT" .
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 1.0
Idle (Engine is warmed-up to normal
operating temperature.)1.2 - 1.8
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.4
Idle to about 4,000 rpm* 1.2 - 1.8 to Approx. 4.0
PBIB1106E

DTC P0112, P0113 IAT SENSOR
EC-837
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0112, P0113 IAT SENSORPFP:22630
Component DescriptionABS00C1K
The intake air temperature sensor is built-into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM termi-
nals, such as the ground.
On Board Diagnosis LogicABS00C1L
DTC Confirmation ProcedureABS00C1M
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-840, "
Diagnostic Procedure"
.
SEC266C
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
-10 (14) 4.43 7.9 - 9.3
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
SEF012P
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0112
0112Intake air tempera-
ture sensor circuit
low inputAn excessively low voltage from the sensor is
sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted.)

Intake air temperature sensor
P0113
0113Intake air tempera-
ture sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF058Y

EC-840
[VK45DE]
DTC P0112, P0113 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00C1O
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-791, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor (intake air temperature sensor
is built-into) harness connector.
2. Turn ignition switch ON.
3. Check voltage between mass air flow sensor terminal 5 and
ground.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
PBIB2195E
PBIB1502E
Voltage: Approximately 5V
PBIB0066E

DTC P0112, P0113 IAT SENSOR
EC-841
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
3. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow 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 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-841, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
5. CHECK INTERMITTENT INCIDENT
Refer to EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS00C1P
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor terminals 5 and
6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationABS00C1Q
MASS AIR FLOW SENSOR
Refer to EM-172, "AIR CLEANER AND AIR DUCT" . Continuity should exist.
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.9 - 2.1
SEC266C
SEF012P

EC-858
[VK45DE]
DTC P0127 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
DTC P0127 IAT SENSORPFP:22630
Component DescriptionABS00C2C
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM termi-
nals, such as the ground.
On Board Diagnosis LogicABS00C2D
DTC Confirmation ProcedureABS00C2E
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Wait until engine coolant temperature is less than 90°C (194°F)
a. Turn ignition switch ON.
SEC266C
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
–10 (14) 4.43 7.9 - 9.3
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127Intake air temperature
too highRationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.

Harness or connectors
(The sensor circuit is open or shorted)

Intake air temperature sensor

DTC P0127 IAT SENSOR
EC-859
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90°C (194°F),
turn ignition switch OFF and cool down engine.

Perform the following steps before engine coolant tempera-
ture is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con-
secutive seconds.
6. If 1st trip DTC is detected, go to EC-859, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS00C2F
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-791, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-841, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
SEF189Y
PBIB2195E

EC-860
[VK45DE]
DTC P0127 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS00C2G
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationABS00C2H
MASS AIR FLOW SENSOR
Refer to EM-172, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.9 - 2.1
SEC266C
SEF012P

DTC P0133, P0153 HO2S1
EC-873
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DTC Confirmation ProcedureABS00C2Y
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:

Always perform at a temperature above −10°C (14°F).

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 10 seconds.
3. Turn ignition switch ON and select “HO2S1 (B1) P0133” or “HO2S1 (B2) P0153” of “HO2S1” in “DTC
WORK SUPPORT” mode with CONSULT-II.
4. Touch “START”.
5. Start engine and let it idle for at least 3 minutes.
NOTE:
Do not raise engine speed above 3,000 rpm after this step. If
the engine speed limit is exceeded, return to step 5.
6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen. Maintain the conditions con-
tinuously until “TESTING” changes to “COMPLETED”. (It will
take approximately 40 to 50 seconds.)
If “TESTING” is not displayed after 5 minutes, retry from
step 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0133
0133
(Bank 1)
Heated oxygen sensor
1 circuit slow responseThe response of the voltage signal from the
sensor takes more than the specified time.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 1

Fuel pressure

Fuel injector

Intake air leaks

Exhaust gas leaks

PCV valve

Mass air flow sensor P0153
0153
(Bank 2)
SEF338Z
ENG SPEED 1,350 - 2,900 rpm
VHCL SPEED SE More than 80 km/h (50 MPH)
B/FUEL SCHDL 1.6 - 12.0 msec
Selector lever Suitable position
SEF339Z

DTC P0133, P0153 HO2S1
EC-879
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Revision: 2004 November 2004 FX35/FX45
3. CHECK FOR EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
SEC502D

EC-880
[VK45DE]
DTC P0133, P0153 HO2S1
Revision: 2004 November 2004 FX35/FX45
5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
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, P0174 or P0172, P0175 detected?
Is it difficult to start engine?
With GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and 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. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-715, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0174 or P0172, P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or DTC P0172, P0175 (Refer to EC-914 or EC-
923 ).
No >> GO TO 6.
SEF968Y
PBIB1502E