O2 sensor NISSAN LATIO 2010 Service Repair Manual

EC-614
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS
Monitored item [Unit]
Description Remarks
ENG SPEED
[rpm] • Indicates the engine speed computed from the signals of the
crankshaft position sensor (POS) and camshaft position sen-
sor (PHASE). • Accuracy becomes poor if engine speed
drops below the idle rpm.
• If the signal is interrupted while the engine is
running, an abnormal value may be indicat-
ed.
MAS A/F SE-B1
[V] • The signal voltage of the mass air flow sensor is displayed. • When the engine is stopped, a certain value
is indicated.
• When engine is running, specification range is indicated in "SPEC".
B/FUEL SCHDL
[ms] • “Base fuel schedule” indicates the fuel injection pulse width
programmed into ECM, prior to any learned on board correc-
tion. • When engine is running, specification range
is indicated in "SPEC".
A/F ALPHA-B1
[%] • The mean value of the air-fuel ratio feedback correction fac-
tor per cycle is indicated. • When the engine is stopped, a certain value
is indicated.
• This data also includes the data for the air/
fuel ratio learning control.
• When engine is running, specification range is indicated in "SPEC".
COOLAN TEMP/S
[ ° C] or [ °F] • The engine coolant temperature (determined by the signal
voltage of the engine coolant temperature sensor) is dis-
played. • When the engine coolant temperature sen-
sor is open or short-circuited, ECM enters
fail-safe mode. The engine coolant temper-
ature determined by the ECM is displayed.
A/F SEN1 (B1)
[V] • The A/F signal computed from the input signal of the A/F sen-
sor 1 is displayed.
HO2S2 (B1)
[V] • The signal voltage of the heated oxygen sensor 2 is dis-
played.
HO2S2 MNTR(B1)
[RICH/LEAN] • Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after three way catalyst
is relatively small.
LEAN: means the amount of oxygen after three way catalyst
is relatively large. • When the engine is stopped, a certain value
is indicated.
VHCL SPEED SE
[km/h] or [mph] • The vehicle speed computed from the vehicle speed signal is
displayed.
BATTERY VOLT
[V] • The power supply voltage of ECM is displayed.
ACCEL SEN 1
[V] • The accelerator pedal position sensor signal voltage is dis-
played. • ACCEL SEN 2 signal is converted by ECM
internally. Thus, it differs from ECM terminal
voltage signal.
ACCEL SEN 2
[V]
TP SEN 1-B1
[V]
• The throttle position sensor signal voltage is displayed. • TP SEN 2-B1 signal is converted by ECM in-
ternally. Thus, it differs from ECM terminal
voltage signal.
TP SEN 2-B1
[V]
FUEL T/TMP SE
[
° C] or [ °F] • The fuel temperature (determined by the signal voltage of the
fuel tank temperature sensor) is displayed.
INT/A TEMP SE
[ ° C] or [ °F] • The intake air temperature (determined by the signal voltage
of the intake air temperature sensor) is indicated.
EVAP SYS PRES
[V ] •

The signal voltage of EVAP control system pressure sensor
is displayed.
FUEL LEVEL SE
[V] • The signal voltage of the fuel level sensor is displayed.
START SIGNAL
[ON/OFF] • Indicates start signal status [ON/OFF] computed by the ECM
according to the signals of engine speed and battery voltage. • After starting the engine, [OFF] is displayed
regardless of the starter signal.
CLSD THL POS
[ON/OFF] • Indicates idle position [ON/OFF] computed by the ECM ac-
cording to the accelerator pedal position sensor signal.
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TROUBLE DIAGNOSISEC-615
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AIR COND SIG
[ON/OFF]
• Indicates [ON/OFF] condition of the air conditioner switch as
determined by the air conditioner signal.
P/N POSI SW
[ON/OFF] • Indicates [ON/OFF] condition from the park/neutral position
(PNP) signal.
PW/ST SIGNAL
[ON/OFF] • [ON/OFF] condition of the power steering system (deter-
mined by the signal sent from EPS control unit) is indicated.
LOAD SIGNAL
[ON/OFF] • Indicates [ON/OFF] condition from the electrical load signal.
ON: Rear window defogger switch is ON and/or lighting
switch is in 2nd position.
OFF: Both rear window defogger switch and lighting switch
are OFF.
IGNITION SW
[ON/OFF] • Indicates [ON/OFF] condition from ignition switch.
HEATER FAN SW
[ON/OFF] • Indicates [ON/OFF] condition from the heater fan switch sig-
nal.
BRAKE SW
[ON/OFF] • Indicates [ON/OFF] condition from the stop lamp switch sig-
nal.
INJ PULSE-B1
[msec] • Indicates the actual fuel injection pulse width compensated
by ECM according to the input signals. • When the engine is stopped, a certain com-
puted value is indicated.
IGN TIMING
[BTDC] • Indicates the ignition timing computed by ECM according to
the input signals. • When the engine is stopped, a certain value
is indicated.
CAL/LD VALUE
[%] • “Calculated load value” indicates the value of the current air-
flow divided by peak airflow.
MASS AIRFLOW
[g·m/s] • Indicates the mass airflow computed by ECM according to
the signal voltage of the mass air flow sensor.
PURG VOL C/V
[%] • Indicates the EVAP canister purge volume control solenoid
valve control value computed by the ECM according to the in-
put signals.
• The opening becomes larger as the value increases.
INT/V TIM(B1)
[ ° CA] • Indicates [
°CA] of intake camshaft advanced angle.
INT/V SOL(B1)
[%] • The control value of the intake valve timing control solenoid
valve (determined by ECM according to the input signal) is in-
dicated.
• The advance angle becomes larger as the value increases
AIR COND RLY
[ON/OFF] • The air conditioner relay control condition (determined by
ECM according to the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF] • Indicates the fuel pump relay control condition determined by
ECM according to the input signals.
VENT CONT/V
[ON/OFF] • The control condition of the EVAP canister vent control valve
(determined by ECM according to the input signals) is indi-
cated.
ON: Closed
OFF: Open
THRTL RELAY
[ON/OFF] • Indicates the throttle control
motor relay control condition de-
termined by the ECM according to the input signals.
COOLING FAN
[HI/LOW/OFF] • Indicates the condition of the cooling fan (determined by
ECM according to the input signals).
HI: High speed operation
LOW: Low speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF] • Indicates [ON/OFF] condition of heated oxygen sensor 2
heater determined by ECM according to the input signals.
I/P PULLY SPD
[rpm] • Indicates the engine speed computed from the input speed
se ns

or signal.
Monitored item [Unit]
Description Remarks
Revision: January 20102010 Versa

EC-616
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS
VEHICLE SPEED
[km/h] or [MPH]• The vehicle speed computed from the vehicle speed signal
sent from TCM is displayed.
IDL A/V LEARN
[YET/CMPLT] • Display the condition of idle air volume learning
YET: Idle Air Volume Learning has not been performed yet.
CMPLT: Idle Air Volume Learning has already been per-
formed successfully.
TRVL AFTER MIL
[km] or [mile] • Distance traveled while MIL is activated.
A/F S1 HTR(B1)
[%] • Indicates A/F sensor 1 heater control value computed by
ECM according to the input signals.
• The current flow to the heater becomes larger as the value in-
creases.
AC PRESS SEN
[V] • The signal voltage from the refrigerant pressure sensor is dis-
played.
VHCL SPEED SE
[km/h] or [MPH] • The vehicle speed computed from the vehicle speed signal
sent from TCM is displayed.
SET VHCL SPD
[km/h] or [MPH] • The preset vehicle speed is displayed.
MAIN SW
[ON/OFF] • Indicates [ON/OFF] condition from MAIN switch signal.
CANCEL SW
[ON/OFF] • Indicates [ON/OFF] condition from CANCEL switch signal.
RESUME/ACC SW
[ON/OFF] • Indicates [ON/OFF] condition from RESUME/ACCELERATE
switch signal.
SET SW
[ON/OFF] • Indicates [ON/OFF] condition from
SET/COAST switch signal.
BRAKE SW1
[ON/OFF] • Indicates [ON/OFF] condition from ASCD brake switch sig-
nal.
BRAKE SW2
[ON/OFF] • Indicates [ON/OFF] condition of stop lamp switch signal.
VHCL SPD CUT
[NON/CUT] • Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set speed.
CUT: Vehicle speed increased to excessively high compared
with the ASCD set speed, and ASCD operation is cut off.
LO SPEED CUT
[NON/CUT] • Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set speed.
CUT: Vehicle speed decreased to excessively low compared
with the ASCD set speed, and ASCD operation is cut off.
AT O D M O N I T O R
[ON/OFF] • Indicates [ON/OFF] condition of A/T O/D according to the in-
put signal from the TCM. • For M/T models always “OFF” is displayed
AT OD CANCEL
[ON/OFF] • Indicates [ON/OFF] condition of A/T O/D cancel signal sent
from the TCM. • For M/T models always “OFF” is displayed
CRUISE LAMP
[ON/OFF] • Indicates [ON/OFF] condition of CRUISE lamp determined
by the ECM according to the input signals.
SET LAMP
[ON/OFF] • Indicates [ON/OFF] condition of SET lamp determined by the
ECM according to the input signals.
A/F ADJ-B1 • Indicates the correction factor stored in ECM. The factor is
calculated from the difference between the target air/fuel ratio
stored in ECM and the air/fuel ratio calculated from air fuel ra-
tio (A/F) sensor 1 signal.
HO2 S2 DIAG1 (B1)
[INCMP/CMPLT] • Indicates DTC P0139 self-diagnosis (delayed response) con-
dition.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.
Monitored item [Unit]
Description Remarks
Revision: January 20102010 Versa

TROUBLE DIAGNOSISEC-617
< SERVICE INFORMATION > [MR18DE]
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
HO2 S2 DIAG2 (B1)
[INCMP/CMPLT]
• Indicates DTC P0139 self-diagnosis (slow response) condi-
tion.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.
A/F SEN1
DIAG1(B1)
[INCMP/CMPLT] • Indicates DTC P015A or P015B self-diagnosis condition.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.
A/F SEN1
DIAG2(B1)
[INCMP/CMPLT] • Indicates DTC P014C or P014D self-diagnosis condition.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.
A/F SEN1
DIAG3(B1)
[ABSNT/PRSNT] • Indicates DTC P014C, P014D, P015A or P015B self-diagno-
sis condition.
ABSNT: The vehicle condition is not within the diagnosis
range.
PRSNT: The vehicle condition is within the diagnosis range.
Monitored item [Unit]
Description Remarks
Test itemCondition JudgmentCheck item (Remedy)
FUEL INJEC-
TION • Engine: Return to the original
trouble condition
• Change the amount of fuel injec- tion using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Harness and connectors
• Fuel injector
• Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING • Engine: Return to the original
trouble condition
• Timing light: Set
• Retard the ignition timing using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Perform Idle Air Volume Learning.
POWER BAL-
ANCE • Engine: After warming up, idle the
engine.
• A/C switch OFF
• Shift lever: P or N (A/T, CVT), Neutral (M/T)
• Cut off each fuel injector signal one at a time using CONSULT-III. Engine runs rough or dies.
• Harness and connectors
• Compression
• Fuel injector
• Power transistor
•Spark plug
• Ignition coil
COOLING FAN* • Ignition switch: ON
• Turn the cooling fan “LOW”, “HI”
and “OFF” with CONSULT-III. Cooling fan moves and stops.
• Harness and connectors
• Cooling fan relay
• Cooling fan motor
ENG COOLANT
TEMP • Engine: Return to the original
trouble condition
• Change the engine coolant tem-
perature using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM. • Harness and connectors
• Engine coolant temperature sen-
sor
• Fuel injector
FUEL PUMP RE-
LAY • Ignition switch: ON
(Engine stopped)
• Turn the fuel pump relay ON and
OFF using CONSULT-III and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
• Harness and connectors
• Fuel pump relay
PURG VOL
CONT/V • Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
• Harness and connectors
• EVAP canister purge volume con-
trol solenoid valve
FUEL/T TEMP
SEN • Change the fuel tank temperature using CONSULT-III.
Revision: January 20102010 Versa

EC-620
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS
2. Connect GST to data link connector (1), which is located under
LH dash panel.
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
5. Perform each diagnostic service according to each service pro- cedure.
For further information, see the GST Operation Manual of
the tool maker.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005532423
Remarks:
z Specification data are reference values.
z Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly relate d to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in spite of the
ignition timing not being adjusted to the specification data. This IGN TIMING moni tors the data calculated by the ECM according to the signals
input from the camshaft position sensor and other ignition timing related sensors.
BBIA0734E
SEF398S
SEF416S
Monitor item Condition Specification
ENG SPEED • Run engine and compare CONSULT-III value with the tachometer indica-
tion. Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-624
.
B/FUEL SCHDL See EC-624
.
A/F ALPHA-B1 See EC-624
.
COOLAN TEMP/S • Engine: After warming up More than 70°C (158 °F)
A/F SEN1 (B1) • Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 2.2 V
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TROUBLE DIAGNOSISEC-623
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*: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, they
differ from
ECM terminals voltage signal. MAIN SW
• Ignition switch: ON MAIN switch: Pressed
ON
MAIN switch: Released OFF
CANCEL SW • Ignition switch: ON CANCEL switch: Pressed
ON
CANCEL switch: Released OFF
RESUME/ACC SW • Ignition switch: ON RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch: Re-
leased OFF
SET SW • Ignition switch: ON SET/COAST switch: Pressed
ON
SET/COAST switch: Released OFF
BRAKE SW1 • Ignition switch: ON • Brake pedal: Fully released (A/T,
CVT)
• Brake pedal and clutch pedal: Fully
released (M/T) ON
• Brake pedal: Slightly depressed (A/T, CVT)
• Brake pedal and/or clutch pedal:
Slightly depressed (M/T) OFF
BRAKE SW2 • Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP • Ignition switch: ON MAIN switch: Pressed at the 1st time
→
at the 2nd time ON
→ OFF
SET LAMP • MAIN switch: ON
• Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH) ACSD: Operating
ON
ASCD: Not operating OFF
HO2 S2 DIAG1 (B1) DTC P0139 self-diagnosis (delayed response) is incomplete.
INCMP
DTC P0139 self-diagnosis (delayed response) is complete. CMPLT
HO2 S2 DIAG2 (B1) DTC P0139 self-diagnosis (slow
response) is incomplete. INCMP
DTC P0139 self-diagnosis (slo w response) is complete. CMPLT
A/F SEN1 DIAG1 (B1) DTC P015A and P015B self-diagnosis is incomplete.
INCMP
DTC P015A and P015B self-diagnosis is complete. CMPLT
A/F SEN1 DIAG2 (B1) DTC P014C and P014D self-diagnosis is incomplete.
INCMP
DTC P014C and P014D self-diagnosis is complete. CMPLT
A/F SEN1 DIAG3 (B1) The vehicle condition is not within the diagnosis range of DTC P014C, P014D,
P015A or P015B.
ABSNT
The vehicle condition is within the diagnosis range of DTC P014C, P014D,
P015A or P015B. PRSNT
Monitor item
Condition Specification
Revision: January 20102010 Versa

EC-624
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000005532424
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in
“SPEC” of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When
the value in “SPEC” of “DATA MONITOR” mode is NOT within the SP value, the Engine Control System may
have one or more malfunctions.
The SP value is used to detect malfunctions that may af fect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
• B/FUEL SCHDL (The fuel injection pulse width progr ammed into ECM prior to any learned on board correc-
tion)
• A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
• MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000005532425
• Vehicle driven distance: More than 5,000 km (3,107 miles)
• Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2, 14.25 - 15.12 psi)
• Atmospheric temperature: 20 - 30 °C (68 - 86° F)
• Engine coolant temperature: 75 - 95 °C (167 - 203° F)
• Transmission: Warmed-up
- A/T and CVT models: After the engine is warmed up to normal operating temperature, drive vehicle until
“FLUID TEMP SE” (A/T or CVT) fluid temperature sensor signal) indicates more than 60 °C (140° F).
- M/T models: After the engine is warmed up to normal operating temperature, drive vehicle for 5 minutes.
• Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight ahead.
• Engine speed: Idle
Inspection ProcedureINFOID:0000000005532426
NOTE:
Perform “SPEC” of “DATA MONITOR” mode in maximum scale display.
1. Perform EC-574, "
Basic Inspection".
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1” and “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode
with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-624, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005532427
OVERALL SEQUENCE
Revision: January 20102010 Versa

EC-628
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
>> GO TO 8.
8.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITO R” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-1019
.)
- Fuel injector and its circuit (Refer to EC-1009
.)
- Intake air leakage
- Low compression pressure (Refer to EM-181, "
On-Vehicle Service".)
2. If NG, repair or replace the malfunctioning part. If OK, replace fuel injector. (It may be caus ed by leakage from fuel injector or clogging.)
>> GO TO 11.
11 .CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITO R” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 12.
12.CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
• For DTC P0130, refer to EC-704, "
DTC Confirmation Procedure".
• For DTC P0131, refer to EC-710, "
DTC Confirmation Procedure".
• For DTC P0132, refer to EC-716, "
DTC Confirmation Procedure".
• For DTC P014C, P014D, P015A, P015B, refer to EC-751, "
DTC Confirmation Procedure".
• For DTC P2A00, refer to EC-989, "
DTC Confirmation Procedure".
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13.CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITO R” mode, and make sure that the indication is within
the SP value.
OK or NG
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-629
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OK >>
INSPECTION END
NG >> GO TO 15.
15.DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin term inal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-592, "
Symptom Matrix Chart".
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” m ode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of alternator, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1” AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1” and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA- B1” is less than the SP value)>>GO TO 21.
21.DISCONNECT AND RECONNECT MASS AI R FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
Revision: January 20102010 Versa

EC-630
< SERVICE INFORMATION >[MR18DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITO R” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-664.
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of NVIS(NATS) system and registration of all NVIS(NATS) ignition key IDs.
Refer to BL-249, "
ECM Re-communicating Function".
3. Perform EC-580, "
VIN Registration".
4. Perform EC-580, "
Accelerator Pedal Released Position Learning".
5. Perform EC-580, "
Throttle Valve Closed Position Learning".
6. Perform EC-580, "
Idle Air Volume Learning".
>> GO TO 29.
25.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system
OK or NG
OK >> GO TO 27.
NG >> Repair or replace malfunctioning part, and then GO TO 26.
26.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (Less than the SP value)>>GO TO 27.
27.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 28.
NG (Less than the SP value)>>Replace mass air flow sensor, and then GO TO 30.
28.CHECK INTAKE SYSTEM
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
Revision: January 20102010 Versa