NISSAN LATIO 2009 Service Repair Manual

DTC P0101 MAF SENSOR
EC-655
< SERVICE INFOMATION >
[MR TYPE 1] C
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DTC P0101 MAF SENSOR
Component Description INFOID:0000000004537112
The mass air flow sensor (1) is plac ed 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 Mode INFOID:0000000004537113
Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004537114
DTC Confirmation Procedure INFOID:0000000004537115
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. PBIA9559J
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 • See EC-618 .
CAL/LD VALUE • Engine: After warming up
• Shift lever: P or N (A/T, CVT), Neutral (M/T)
• Air conditioner switch: OFF
• No load Idle 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 load Idle 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
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

EC-656< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0101 MAF SENSOR
PROCEDURE FOR MALFUNCTION A
NOTE:
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-659, " Diagnosis Procedure " .
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-III
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-659, " Diagnosis Procedure " .
3. Select “DATA MONITOR” mode with CONSULT-III.
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-659, " Diagnosis Procedure " .
If OK, go to following step.
7. Maintain the following conditions for at least 10 consecutive seconds.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-659, " Diagnosis Procedure " .
Overall Function Check INFOID:0000000004537116
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the ma ss air flow sensor circuit. During this check, a 1st
DTC might not be confirmed.
With GST PBIB3457E
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Shift lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.

DTC P0101 MAF SENSOR
EC-657
< SERVICE INFOMATION >
[MR TYPE 1] C
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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-659, " Diagnosis Procedure " .
SEF534P

EC-658< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0101 MAF SENSOR
Wiring Diagram INFOID:0000000004537117
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. BBWA2632E

DTC P0101 MAF SENSOR
EC-659
< SERVICE INFOMATION >
[MR TYPE 1] C
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Diagnosis Procedure
INFOID:00000000045371181.
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. 3.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-632, " Ground Inspection " .
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
32 P ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition switch
OFF 0 - 1.0V
[Ignition switch: OFF]
• More than a few seconds after turning ignition switch OFF BATTERY VOLTAGE
(11 - 14V)
45 G Mass air flow sensor [Engine is running]
• Warm-up condition
• Idle speed 0.8 - 1.1V
[Engine is running]
• Warm-up condition
• Engine speed: 2,500 rpm 1.4 - 1.7V
52 LG Sensor ground
(Mass air flow sensor) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V
105 G Power supply for
ECM [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V) BBIA0698E

OK >> GO TO 4.
NG >> Repair or replace ground connections. OK >> GO TO 6.
NG >> GO TO 5. OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.

EC
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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. Component Inspection " .
OK or NG OK >> GO TO 9.
NG >> Replace intake air temperature sensor. Component Inspection " .
OK or NG OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor. Component Inspection " .
OK or NG OK >> GO TO 11.
NG >> Replace mass air flow sensor. .
>> INSPECTION END
Component Inspection INFOID:0000000004537119
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 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 Continuity should exist.

EC-662< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0101 MAF SENSOR
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.
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 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 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 malfunc tioning 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 Installation INFOID:0000000004537120
MASS AIR FLOW SENSOR
Refer to EM-139 .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

DTC P0102, P0103 MAF SENSOR
EC-663
< SERVICE INFOMATION >
[MR TYPE 1] C
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DTC P0102, P0103 MAF SENSOR
Component Description INFOID:0000000004537121
The mass air flow sensor (1) is plac ed 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 Mode INFOID:0000000004537122
Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004537123
These self-diagnoses have the on e trip detection logic.
FAIL-SAFE MODE When the malfunction is detec ted, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004537124
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. PBIA9559J
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-618 .
CAL/LD VALUE • Engine: After warming up
• Shift lever: P or N (A/T, CVT), Neutral (M/T)
• Air conditioner switch: OFF
• No load Idle 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 load Idle 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
P0102
0102 Mass air flow sensor
circuit low input An excessively low voltage from the sensor is sent
to ECM. • Harness or connectors
(Mass air flow sensor circuit is open or short-
ed.)
• 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
(Mass air flow sensor circuit is open or short-
ed.)
• 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.

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-666, " 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-666, " Diagnosis Procedure " .