2001 NISSAN ALMERA o2 sensor

SEF553Y
JEF096Y
SEF097Y
ECM Terminals and Reference ValueNJEC0044PREPARATIONNJEC0044S01Models with ECM in Engine CompartmentNJEC0044S01011. The ECM is located under the cowl panel on the passenger
side (behind the strut tower). Remove it from the engine room
side.
+Remove the bracket fixing ECM harness.
+Remove the quick connector of the ventilation hose in the ECM
compartment room by pressing in the direction of the arrow.
+Pull the ECM box out from under the cowl panel by removing
the two ECM box attaching bolts.
+Remove the five bolts on ECM box installation cover.
: 3.9 - 6.9 N´m (0.39 - 0.71 kg-m, 34 - 61 in-lb)
+Remove the three ECM installation bolts.
: 4.1 - 6.8 N´m (0.41 - 0.70 kg-m, 36 - 60 in-lb)
SEF098Y
2. Remove ECM harness protector.
SEF908W
+When connecting or disconnecting ECM harness
connector, use lever as shown.
When connecting, fasten connector securely with lever
moved until it stops.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Major Sensor Reference Graph in Data Monitor Mode (Cont'd)
EC-164

ECM HARNESS CONNECTOR TERMINAL LAYOUTNJEC0044S02
SEF970W
ECM INSPECTION TABLENJEC0044S03Specification 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 damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 Y/RIntake valve timing con-
trol solenoid valve[Engine is running]
+Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Lift up drive wheels and suitable gear posi-
tion
+Rev engine from 2,000 to 3,000 rpmApproximately 0V
3 W/RHeated oxygen sensor 2
heater (rear)[Engine is running]
+Engine speed is below 3,600 rpm
+After driving for 2 minutes at a speed of 70
km/h (43 MPH) or moreApproximately 0.7V
[Ignition switch ªONº]
+Engine stopped
+Engine speed is above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
4 R/BHeated oxygen sensor 1
heater (front)[Engine is running]
+Engine speed is below 3,200 rpmApproximately 0V
[Engine is running]
+Engine speed is above 3,200 rpmBATTERY VOLTAGE
(11 - 14V)
6
7
15
16BR
L/G
P
ORIACV-AAC valve[Engine is running]
+Warm-up condition
+Idle speed0.1 - 14V
8*
9*
17*
18*SB
W/B
R/Y
BR/REGR volume control
valve[Engine is running]
+Warm-up condition
+Rev engine from 2,000 to 4,000 rpm0 - 14V
10 Y/B A/T signal No. 3[Engine is running]
+Idle speedApproximately 0V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-166

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
50 L/BElectrical load signal
(Headlamp and
Rear defogger)[Engine is running]
+Headlamp switch or rear defogger switch is
ªONºBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Headlamp switch and rear defogger switch
are ªOFFºApproximately 0V
51 LG/B Blower fan SW[Ignition switch ªONº]
+Blower fan switch is ªONºApproximately 0V
[Ignition switch ªONº]
+Blower fan switch is ªOFFºApproximately 5V
54 Y/R A/T signal No. 1[Engine is running]
+Idle speedApproximately 0V
55 Y/G A/T signal No. 2[Engine is running]
+Idle speedApproximately 0V
56 G/Y A/T signal No. 4[Engine is running]
+Idle speedApproximately 0V
57 B ECM ground[Engine is running]
+Idle speedEngine ground
58 B Sensors' ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
61 G 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 rpm1.5 - 2.1V
62 WHeated oxygen sensor 1
(front)[Engine is running]
+Warm-up condition
+Engine speed is 2,000 rpm0 - Approximately 0.7V
SEF008W
63 LHeated oxygen sensor 2
(rear)[Engine is running]
+After warming up to normal operating tem-
perature and engine speed is 3,000 rpm0 - Approximately 1.0V
64 Y/BIntake air temperature
sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with
intake air temperature
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-169

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
66
75R
RCamshaft position sen-
sor (PHASE)[Engine is running]
+Warm-up condition
+Idle speed2.0 - 3.0V
SEF977W
[Engine is running]
+Engine speed is 2,000 rpm2.0 - 3.0V
SEF978W
67 W/LPower supply for ECM
(Back-up)[Ignition switch ªOFFº]BATTERY VOLTAGE
(11 - 14V)
70 BR/WEngine coolant tempera-
ture sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature
71 GYThrottle position sensor
signal output[Engine is running]
+Warm-up condition
+Accelerator pedal fully releasedApproximately 0.4V
[Ignition switch ªONº]
+Accelerator pedal fully depressedApproximately 4V
72* P/B EGR temperature sensor[Engine is running]
+Warm-up condition
+Idle speedLess than 4.5V
[Engine is running]
+Warm-up condition
+EGR system is operating0 - 1.0V
73 BMass air flow sensor
ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
74 R/LRefrigerant pressure
sensor[Engine is running]
+Air conditioner switch is ªONº
(Compressor operates)1.0 - 4.0V
[Engine is running]
+Warm-up condition
+Idle speed
+Air conditioner switch is turned from ªONº to
ªOFFºVoltage is gradually decreasing.
81 W Knock sensor[Engine is running]
+Idle speed1.0 - 4.0V
82* L/WFuel tank temperature
sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with fuel
temperature
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-170

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
85 RCrankshaft position sen-
sor (POS)[Engine is running]
+Warm-up condition
+Idle speed3.0 - 4.0V
SEF979W
[Engine is running]
+Engine speed is 2,000 rpm3.0 - 4.0V
SEF980W
86 PU/R Vehicle speed sensor[Engine is running]
+Lift up the vehicle
+Vehicle speed is 40 km/h (25 MPH)2.5-3V
SEF976W
91 PU A/T check signal[Engine is running]
+Idle speed0 - Approximately 5V
92 Y Throttle position sensor[Engine is running]
+Accelerator pedal released0.15 - 0.85V
[Ignition switch ªONº]
+Accelerator pedal fully depressed3.5 - 4.7V
93 G/R Data link connector[Engine is running]
+Idle speed (CONSULT-II or GST is discon-
nected)Approximately 0V
101
103
105
107R/B
YB
GB
L/BInjector No. 1
Injector No. 2
Injector No. 3
Injector No. 4[Engine is running]
+Warm-up condition
+Idle speedBATTERY VOLTAGE
(11 - 14V)
SEF011W
[Engine is running]
+Warm-up condition
+Engine speed is 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
SEF012W
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-171

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
104* SBSwirl control valve con-
trol solenoid valve[Engine is running]
+Engine coolant temperature is between 15ÉC
(59ÉF) to 40ÉC (104ÉF)
+Idle speed0-1V
[Engine is running]
+Engine coolant temperature is above 40ÉC
(104ÉF)
+Idle speedBATTERY VOLTAGE
(11 - 14V)
106
108B/Y ECM ground[Engine is running]
+Idle speedEngine ground
11 0
11 2W
WPower supply for ECM[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
111 R Sensors' power supply[Ignition switch ªONº]Approximately 5V
114 GY/R Adjust switch[Engine is running]
+Idle speed0V
115 LG Data link connector[Engine is running]
+Idle speed (CONSULT-II or GST is discon-
nected)0 - 10V
* If so equipped
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-172

DescriptionNJEC1265The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º 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 ConditionNJEC1266+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 - 30ÉC (68 - 86ÉF)
+Engine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
+Transmission: Warmed-up*1
+Electrical load: Not applied*2
+Engine speed: Idle
*1: For A/T or CVT models, after the engine is warmed up to normal operating temperature, drive vehicle until
ªFLUID TEMP SEº (A/T or CVT fluid temperature sensor signal) indicates less than 0.9V. For M/T models, drive
vehicle for 5 minutes after the engine is warmed up to normal operating temperature.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNJEC1267NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-100.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-174.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUEQG
Description
EC-173

SEF987W
Component DescriptionNJEC0050The mass air flow sensor is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. It consists of a hot wire that is supplied with electric
current from the ECM. The temperature of the hot wire is controlled
by the ECM 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 ECM must supply more electric current 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
Mode
NJEC0051Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: ªNº
+No-loadIdle 1.0 - 1.7V
2,500 rpm 1.5 - 2.1V
MASS AIRFLOW+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: ªNº
+No-loadIdle 1.0 - 4.0 g´m/s
2,500 rpm 5.0 - 10.0 g´m/s
ECM Terminals and Reference ValueNJEC0052Specification 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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
61 G 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 rpm1.5 - 2.1V
73 BMass air flow sensor
ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
On Board Diagnosis LogicNJEC0053
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0100
0100A) An excessively high voltage from the sensor is sent
to ECM when engine is not running.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air flow sensor
B) An 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
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Component Description
EC-187