2007 NISSAN LATIO sensor

EC-178Revision: June 2006
DTC P0101 MAF SENSOR
2007 Versa
DTC P0101 MAF SENSORPFP:22680
Component DescriptionUBS00QD1
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 ModeUBS00QD2
Specification data are reference values.
On Board Diagnosis LogicUBS00QD3
DTC Confirmation ProcedureUBS00QD4
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 conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PBIA9559J
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1

See EC-133, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Shift lever: P or N (A/T, CVT),
Neutral (M/T)

Air conditioner switch: OFF

No loadIdle 10% - 35%
2,500 rpm 10% - 35%
MASS AIRFLOW

Engine: After warming up

Shift lever: P or N (A/T, CVT),
Neutral (M/T)

Air conditioner switch: OFF

No loadIdle 1.0 - 4.0 g·m/s
2,500 rpm 4.0 - 10.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0101
0101Mass air flow sensor cir-
cuit range/performanceA)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
under 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

DTC P0101 MAF SENSOR
EC-179
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Revision: June 20062007 Versa
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and warm it up to normal operating temperature.
4. Run engine for at least 10 seconds at idle speed.
5. If 1st trip DTC is detected, go to EC-182, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-182, "
Diagnostic Procedure" .
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
5. Increases engine speed to about 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-182, "
Diagnostic Procedure" .
If OK, go to following step.
SEF 1 74 Y
SEF 2 43 Y

EC-180Revision: June 2006
DTC P0101 MAF SENSOR
2007 Versa
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-182, "
Diagnostic Procedure"
.
Overall Function CheckUBS00QD5
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st
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-182, "
Diagnostic Procedure" .
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Shift lever Suitable position
Driving locationDriving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF 5 34 P

DTC P0101 MAF SENSOR
EC-181
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Revision: June 20062007 Versa
Wiring DiagramUBS00QD6
BBWA2632E

EC-182Revision: June 2006
DTC P0101 MAF SENSOR
2007 Versa
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 ProcedureUBS00QD7
1. INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A >> GO TO 3.
B >> GO TO 2.
2. CHECK INTAKE AIR LEAK
Check the following for connections.

Air duct

Vacuum hoses

Intake air passage between air duct and intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
32 PECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition switch
OFF0 - 1.0V
[Ignition switch: OFF]

More than a few seconds after turning ignition
switch OFFBATTERY VOLTAGE
(11 - 14V)
45 G Mass air flow sensor[Engine is running]

Warm-up condition

Idle speed0.8 - 1.1V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm1.4 - 1.7V
52 LGSensor ground
(Mass air flow sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
105 GPower supply for
ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)

DTC P0101 MAF SENSOR
EC-183
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Revision: June 20062007 Versa
3. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-150, "
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.
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
BBIA0698E
BBIA0701E
Voltage: Battery voltage
PBIB11 68 E

EC-184Revision: June 2006
DTC P0101 MAF SENSOR
2007 Versa
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E8, F8

Harness for open or short between mass air flow sensor and IPDM E/R

Harness for open or short between mass air flow sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
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 52.
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 45.
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 or short to power in harness or connectors.
8. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-217, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-384, "
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-185, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.Continuity should exist.
Continuity should exist.

DTC P0101 MAF SENSOR
EC-185
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11 . CHECK INTERMITTENT INCIDENT
Perform EC-143, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00QD8
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.
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 45 (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.
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx 0.4
Idle (Engine is warmed-up to normal
operating temperature.)0.8 - 1.1
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.4 - 1.7
Idle to about 4,000 rpm 0.8 - 1.1 to 2.4*
PBIB2371E
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx 0.4
Idle (Engine is warmed-up to normal
operating temperature.)0.8 - 1.1
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.4 - 1.7
Idle to about 4,000 rpm 0.8 - 1.1 to 2.4*
PBIA9564J