Mass air flow INFINITI M35 2007 Factory Owner's Guide

DTC P0101 MAF SENSOR
EC-201
[VQ35DE]
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Revision: 2007 April2007 M35/M45
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 harness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and InstallationNBS004UW
MASS AIR FLOW SENSOR
Refer to EM-19, "AIR CLEANER AND AIR DUCT" .

EC-202
[VQ35DE]
DTC P0102, P0103 MAF SENSOR
Revision: 2007 April2007 M35/M45
DTC P0102, P0103 MAF SENSORPFP:22680
Component DescriptionNBS004UX
The mass air flow sensor (1) 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 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-II Reference Value in Data Monitor ModeNBS004UY
Specification data are reference values.
On Board Diagnosis LogicNBS004UZ
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.
PBIA9559J
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-143, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0102
0102Mass air flow 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 leaks

Mass air flow sensor
P0103
0103Mass air flow sensor
circuit high inputAn 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 not rise more than 2,400 rpm due to the fuel cut.

DTC P0102, P0103 MAF SENSOR
EC-205
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Revision: 2007 April2007 M35/M45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureNBS004V2
1. INSPECTION START
Which malfunction (P0102 or P0103) is duplicated?
P0102 or P0103
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2. CHECK INTAKE SYSTEM
Check the following for connection.

Air duct

Va c u u m h o s e s

Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
51 W Mass air flow sensor[Engine is running]

Warm-up condition

Idle speed0.9 - 1.2V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm1.6 - 1.9V
67 B/W Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
111 S BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 9
120R
RPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)

EC-206
[VQ35DE]
DTC P0102, P0103 MAF SENSOR
Revision: 2007 April2007 M35/M45
3. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-160, "
Ground Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace ground connections.
4. CHECK MAF SENSOR POWER 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-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E108, M15

Harness connectors M72, 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.
1. Body ground M70 2. Body ground M16
PBIB2782E
PBIB2783E
Voltage: Battery voltage
PBIB1168E

DTC P0102, P0103 MAF SENSOR
EC-207
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Revision: 2007 April2007 M35/M45
6. CHECK MAF SENSOR GROUND CIRCUIT 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.
8. CHECK MASS AIR FLOW SENSOR
Refer to EC-207, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS004V3
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing 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.Continuity should exist.
Continuity should exist.
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)0.9 - 1.2
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.6 - 1.9
Idle to about 4,000 rpm 0.9 - 1.2 to Approx. 2.4*
PBIB2371E

EC-208
[VQ35DE]
DTC P0102, P0103 MAF SENSOR
Revision: 2007 April2007 M35/M45
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 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.
Without CONSULT-II
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.
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 harness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and InstallationNBS004V4
MASS AIR FLOW SENSOR
Refer to EM-19, "AIR CLEANER AND AIR DUCT" .
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)0.9 - 1.2
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.6 - 1.9
Idle to about 4,000 rpm 0.9 - 1.2 to Approx. 2.4*
PBIB1106E

DTC P0112, P0113 IAT SENSOR
EC-209
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Revision: 2007 April2007 M35/M45
DTC P0112, P0113 IAT SENSORPFP:22630
Component DescriptionNBS004V5
The intake air temperature sensor is built-into mass air flow sensor
(1). 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.

*: This data is reference value and is 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 terminals, such as the ground.
On Board Diagnosis LogicNBS004V6
DTC Confirmation ProcedureNBS004V7
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-212, "
Diagnostic Procedure"
.
PBIA9559J
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
25 (77) 3.3 1.800 - 2.200
80 (176) 1.2 0.283 - 0.359
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-212
[VQ35DE]
DTC P0112, P0113 IAT SENSOR
Revision: 2007 April2007 M35/M45
Diagnostic ProcedureNBS004V9
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-160, "
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) (1) harness connector.
2. Turn ignition switch ON.
3. Check voltage between mass air flow sensor terminal 5 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
1. Body ground M70 2. Body ground M16
PBIB2782E
PBIB2783E
Voltage: Approximately 5V
PBIB1169E

DTC P0112, P0113 IAT SENSOR
EC-213
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Revision: 2007 April2007 M35/M45
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 6 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-213, "
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-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS004VA
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor (1) terminals 5
and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationNBS004VB
MASS AIR FLOW SENSOR
Refer to EM-19, "AIR CLEANER AND AIR DUCT" . Continuity should exist.
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.800 - 2.200
PBIA9559J
SEF012P

DTC P0127 IAT SENSOR
EC-229
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Revision: 2007 April2007 M35/M45
DTC P0127 IAT SENSORPFP:22630
Component DescriptionNBS004VX
The intake air temperature sensor is built-into mass air flow sensor
(1). 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.

*: This data is reference value and is 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 terminals, such as the ground.
On Board Diagnosis LogicNBS004VY
DTC Confirmation ProcedureNBS004VZ
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.
PBIA9559J
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
25 (77) 3.3 1.800 - 2.200
80 (176) 1.2 0.283 - 0.359
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