2003 NISSAN ALMERA N16 mass air flow sensor

EC-88
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-40, "
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME
DATA" .ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC
*1FREEZE
FRAME
DATA
*2
SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS)××××
Camshaft position sensor (PHASE)××××
Mass air flow sensor×××
Engine coolant temperature sensor×××××
Heated oxygen sensor 1×××××
Heated oxygen sensor 2×××××
Vehicle speed signal××××
Accelerator pedal position sensor×××
Throttle position sensor×××
Intake air temperature sensor××××
Knock sensor×
Refrigerant pressure sensor××
Closed throttle position switch
(accelerator pedal position sensor
signal)××
Air conditioner switch××
Park/neutral position (PNP) switch×××
Stop lamp switch×××
Power steering pressure sensor×××
Battery voltage××
Electrical load signal××
OUTPUT
Injectors×× ×
Power transistor (Ignition timing)×× ×
Throttle control motor relay×××
Throttle control motor×
EVAP canister purge volume con-
trol solenoid valve××××
Air conditioner relay××
Fuel pump relay××××
Cooling fan relay××××
Heated oxygen sensor 1 heater××××
Heated oxygen sensor 2 heater××××
Intake valve timing control solenoid
valve××××
Calculated load value×××

TROUBLE DIAGNOSIS
EC-91
[QG (WITH EURO-OBD)]
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EC
DATA MONITOR MODE
Monitored Item
×: Applicable
Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSCAN
DIAG
SUP-
PORT
MNTRDescription Remarks
ENG SPEED [rpm]××
●Indicates the engine speed computed
from the signals of the crankshaft posi-
tion sensor (POS) and camshaft posi-
tion sensor (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 indicated.
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.
B/FUEL SCHDL
[msec]×
●“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
A/F ALPHA-B1 [%]×
●The mean value of the air-fuel ratio
feedback correction factor 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 con-
trol.
COOLAN TEMP/S
[°C] or [°F]××
●The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.
●When the engine coolant tempera-
ture sensor is open or short-cir-
cuited, ECM enters fail-safe mode.
The engine coolant temperature
determined by the ECM is dis-
played.
HO2S1 (B1) [V]××
●The signal voltage of the heated oxygen
sensor 1 is displayed.
HO2S2 (B1) [V]×
●The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S1 MNTR (B1)
[RICH/LEAN]××
●Display of heated oxygen sensor 1 sig-
nal during air-fuel ratio feedback control:
RICH ... means the mixture became
“rich”, and control is being affected
toward a leaner mixture.
LEAN ... means the mixture became
“lean”, and control is being affected
toward a rich mixture.●After turning ON the ignition
switch, “RICH” is displayed until
air-fuel mixture ratio feedback
control begins.
●When the air-fuel ratio feedback is
clamped, the value just before the
clamping is displayed continu-
ously.
HO2S2 MNTR (B1)
[RICH/LEAN]×
●Display of heated oxygen sensor 2 sig-
nal:
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 dis-
played.
ACCEL SEN 1 [V]××
●The accelerator pedal position sensor
signal voltage is displayed.
ACCEL SEN 2 [V]×

EC-92
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
THRTL SEN 1 [V]××●The throttle position sensor signal volt-
age is displayed.
THRTL SEN 2 [V]×
INT/A TEMP SE
[°C] or [°F]××
●The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
START SIGNAL
[ON/OFF]××
●Indicates [ON/OFF] condition of the
starter signal computed from the signals
of the crankshaft position sensor (POS),
camshaft position sensor (PHASE) 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] com-
puted by ECM according to the acceler-
ator pedal position sensor signal.
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) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF]××
●[ON/OFF] condition of the power steer-
ing oil pressure switch as determined by
the power steering oil pressure signal 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 posi-
tion.
OFF ... Both rear window defogger
switch and lighting switch are OFF.
IGNITION SW
[ON/OFF]×
●Indicates [ON/OFF] condition from igni-
tion switch.
HEATER FAN SW
[ON/OFF]×
●Indicates [ON/OFF] condition from the
heater fan switch signal.
BRAKE SW
[ON/OFF]×
●Indicates [ON/OFF] condition from the
stop lamp switch signal.
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 computed value is indi-
cated.
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 airflow 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. Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSCAN
DIAG
SUP-
PORT
MNTRDescription Remarks

EC-94
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
NOTE:
●Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
●Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically. Voltage [V]
●Voltage, frequency, duty cycle or pulse
width measured by the probe.
●Only “#” is displayed if item is
unable to be measured.
●Figures with “#”s are temporary
ones. They are the same figures
as an actual piece of data which
was just previously measured. Frequency
[msec], [Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOW
CAN COMM
[OK/NG]×
●Indicates the communication condition
of CAN communication line.●These items are not displayed in
“SELECTION FROM MENU”
mode. CAN CIRC 1
[OK/UNKWN]×
CAN CIRC 2
[OK/UNKWN]×
CAN CIRC 3
[OK/UNKWN]×
CAN CIRC 4
[OK/UNKWN]×
CAN CIRC 5
[OK/UNKWN]×
CAN CIRC 6
[OK/UNKWN]×
CAN CIRC 7
[OK/UNKWN]× Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSCAN
DIAG
SUP-
PORT
MNTRDescription Remarks
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]××
●Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS).
MAS A/F SE-B1 [V]××
●The signal voltage of the mass air flow
sensor specification is displayed.●When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]×
●“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
●When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]×
●The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.●When engine is running specification
range is indicated.
●This data also includes the data for the
air-fuel ratio learning control.

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-105
[QG (WITH EURO-OBD)]
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionEBS00K3Y
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” 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 affect 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 programmed into ECM prior to any learned on board cor-
rection)
●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 ConditionEBS00K3Z
●Vehicle driven distance: More than 5,000 km (3,017 miles)
●Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2 , 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*1
●Electrical load: Not applied*2
●Engine speed: Idle
*1: For A/T models, after the engine is warmed up to normal operating temperature, drive vehicle until “FLUID
TEMP SE” (A/T fluid temperature sensor signal) indicates more than 60°C (140°F).
For M/T models, after the engine is warmed up to normal operating temperature, drive vehicle for 5 minutes.
*2: Rear window defogger switch, air conditioner switch, lighting switch are “OFF”. Steering wheel is straight
ahead.
Inspection ProcedureEBS00K40
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-65, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1/B2” and “MAS A/F
SE-B1” in “DATA MONITOR (SPEC)” mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-106, "
Diagnostic Procedure" .
SEF601Z

EC-128
[QG (WITH EURO-OBD)]
DTC P0037, P0038 HO2S2 HEATER
DTC P0037, P0038 HO2S2 HEATER
PFP:226A0
DescriptionEBS00K4P
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeEBS00K4Q
Specification data are reference values.
On Board Diagnosis LogicEBS00K4R
DTC Confirmation ProcedureEBS00K4S
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:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch “ON” and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch ″OFF″ and wait at least 10 seconds.
Sensor Input Signal to ECM ECM Function Actuator
Camshaft position sensor (PHASE)
Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater Crankshaft position sensor (POS)
Engine coolant temperature sensorEngine coolant tempera-
ture
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,800 OFF
●Below 3,800 rpm after the following conditions are met.
●Engine: After warming up
●Keeping the engine speed between 3,500 and 4,000 rpm for
one minute and at idle for one minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
●Engine speed: Below 3,800 rpm after the following conditions are met.
●Engine: After warming up
●Keeping the engine speed between 3,500 and 4,000 rpm for one minute
and at idle for one minute under no loadON
●Engine speed: Above 3,800 rpm OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037Heated oxygen sensor 2
heater control circuit lowThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
●Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
●Heater oxygen sensor 2 heater
P0038
0038Heated oxygen sensor 2
heater control circuit highThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
●Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
●Heater oxygen sensor 2 heater

EC-134
[QG (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR
DTC P0102, P0103 MAF SENSOR
PFP:22680
Component DescriptionEBS00K4X
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. It consists of a hot film that is supplied with electric current from
the ECM. The temperature of the hot film is controlled by the ECM a
certain amount. The heat generated by the hot film is reduced as the
intake air flows around it. The more air, the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeEBS00K4Y
Specification data are reference values.
On Board Diagnosis LogicEBS00K4Z
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 MI lights up.
SEC266C
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1
●Engine: After warming up
●Air conditioner switch: OFF
●Shift lever:
N (A/T models)
Neutral (M/T models)
●No-loadIdle Approx. 1.0 - 1.7V
2,500 rpm Approx. 1.5 - 2.1V
CAL/LD VALUE
●Engine: After warming up
●Shift lever:
N (A/T models)
Neutral (M/T models)
●Air conditioner switch: OFF
●No-loadIdle 10% - 35%
2,500 rpm 10% - 35%
MASS AIRFLOW
●Engine: After warming up
●Shift lever:
N (A/T models)
Neutral (M/T models)
●Air conditioner switch: OFF
●No-loadIdle 1.0 - 4.0 g·m/s
2,500 rpm 5.0 - 10.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0102
0102Mass air flow sensor circuit
low inputAn excessively low voltage from the sensor
is sent to ECM when engine is running.
●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-137
[QG (WITH EURO-OBD)]
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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 ProcedureEBS00K52
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
●Vacuum hoses
●Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
3.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 4.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
45 RSensor power supply
(Mass air flow sensor)[Ignition switch “ON”]Approximately 5V
50 Y Mass air flow sensor[Engine is running]
●Warm-up condition
●Idle speed1.0 - 1.7V
[Engine is running]
●Warm-up condition
●Engine speed is 2,500 rpm.1.5 - 2.1V
67 BSensor ground
(Mass air flow sensor)[Engine is running]
●Warm-up condition
●Idle speedApproximately 0V
MBIB0095E