2001 NISSAN ALMERA o2 sensor

Normal ControlNJEC0612S04Input/Output Signal ChartNJEC0612S0401
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speedFuel injection
control (Normal
control)Electronic control fuel
injection pump
Accelerator position sensor Accelerator position
SEF649S
The amount of fuel injected under normal driving conditions is determined according to sensor signals. The
crankshaft position sensor (TDC) detects engine speed and the accelerator position sensor detects accelera-
tor position. These sensors send signals to the ECM.
The fuel injection data, predetermined by correlation between various engine speeds and accelerator positions,
are stored in the ECM memory, forming a map. The ECM determines the optimal amount of fuel to be injected
using the sensor signals in comparison with the map.
Maximum Amount ControlNJEC0612S05Input/Output Signal ChartNJEC0612S0501
Sensor Input Signal to ECM ECM Function Actuator
Mass air flow sensor Amount of intake air
Fuel injection
control (Maxi-
mum amount
control)Electronic control fuel
injection pump Engine coolnat temperature sensor Engine coolant temperature
Crankshaft position sensor (TDC) Engine speed
Accelerator position sensor Accelerator position
The maximum injection amount is controlled to an optimum by the engine speed, intake air amount, engine
coolant temperature, and accelerator opening in accordance with the driving conditions.
This prevents the oversupply of the injection amount caused by decreased air density at a high altitude or
during a system failure.
Deceleration ControlNJEC0612S06Input/Output Signal ChartNJEC0612S0601
Sensor Input Signal to ECM ECM Function Actuator
Accelerator position switch Accelerator positionFuel injection
control (Decel-
eration control)Electronic control fuel
injection pump
Crankshaft position sensor (TDC) Engine speed
The ECM sends a fuel cut signal to the electronic control fuel injection pump during deceleration for better
fuel efficiency. The ECM determines the time of deceleration according to signals from the accelerator posi-
tion switch and crankshaft position sensor (TDC).
Fuel Injection Timing Control System
DESCRIPTIONNJEC0613The target fuel injection timing in accordance with the engine speed and the fuel injection amount are recorded
as a map in the ECM beforehand. The ECM and the injection pump control unit exchange signals and per-
form feedback control for optimum injection timing in accordance with the map.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System (Cont'd)
EC-611

Air Conditioning Cut Control
DESCRIPTIONNJEC0614Input/Output Signal ChartNJEC0614S01
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner ªONº signal
Air conditioner
cut controlAir conditioner relay Accelerator position sensor Accelerator valve opening angle
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
System DescriptionNJEC0614S02This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the engine coolant temperature returns to normal.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNJEC0615Input/Output Signal ChartNJEC0615S01
Sensor Input Signal to ECM ECM Function Actuator
Vehicle speed sensor Vehicle speed
Fuel cut controlElectronic control fuel
injection pump Accelerator position switch Accelerator position
Crankshaft position sensor (TDC) Engine speed
If the engine speed is above 2,800 rpm with no load (for example, in neutral and engine speed over 2,800
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªFuel Injection Control Systemº,
EC-610.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Air Conditioning Cut Control
EC-612

Fuel Filter
DESCRIPTIONNJEC0623A water draining cock is on the lower side and a priming pump for
bleeding air is on the upper side.
SEF375Y
AIR BLEEDINGNJEC06241. After the repair, bleed air from the piping by pumping the prim-
ing pump up and down until it becomes heavy.
2. To start the engine, rotate the starter for a maximum of 30
seconds. To start the engine more quickly, crank the engine
while pumping the priming pump (requires two workers).
3. If the engine does not start after rotating the starter for a maxi-
mum of 30 seconds, stop it once, and pump the priming pump
again until it becomes heavy.
4. Rotate the starter again until the engine starts running.
5. After the engine starts, let it idle for at least 1 minute to stabi-
lize the behavior.
+When air is bled completely, the pumping of the priming
pump suddenly becomes heavy. Stop the operation at that
time.
+If it is difficult to bleed air by the pumping of the priming
pump (the pumping of the priming pump does not become
heavy), disconnect the fuel supply hose between the fuel
filter and the injection pump. Then, perform the operation
described above, and make sure that fuel comes out. (Use
a pan, etc. so as not to spill fuel. Do not let fuel get on
engine and other parts.) After that, connect the hose, then
bleed air again.
+Start engine and let it idle for at least one minute after
performing air bleeding.
WATER DRAININGNJEC0625+If the MI lights up (not flashes) during the engine operation,
drain the water as follows. (If water in fuel filter sensor is
equipped.)
1. Remove the fuel filter, filter bracket, protector assembly from
the dash panel as follows.
a. Remove the air cleaner case (upper), air duct assembly, and
vacuum hose for brake booster (between the vacuum pump
and vacuum pipe).
CAUTION:
After the duct is removed, cover the opening with gum tape,
etc. to prevent foreign object from getting into the engine
during the operation.
b. Disconnect the water level warning sensor harness connector.
c. Remove the mounting nuts on the dash panel, then remove the
fuel filter, filter bracket, and protector assembly from the dash
panel.
+It is not necessary to disconnect the fuel hose.
2. Using a tool such as a pliers, loosen the water draining cock
BASIC SERVICE PROCEDUREYD
Fuel Filter
EC-625

at the bottom of the water level warning sensor located under
the fuel filter.
JEF377Y
3. Install the fuel filter, filter bracket, and protector assembly tem-
porarily. Then, drain the water by pumping the priming pump
with the filter standing straight.
+Extend the drain hose if necessary.
Water amount when the MI lights up:
65 - 100 m!(2.3 - 3.5 Imp fl oz)
CAUTION:
When the water is drained, the fuel is also drained. Use a pan,
etc. to avoid fuel adherence to the rubber parts such as the
engine mount insulator.
4. Tighten the water draining cock, then install the fuel filter, filter
bracket, protector assembly in the reverse order of removal.
CAUTION:
Do not over-tighten the water draining cock. This will damage
the cock thread, resulting in water or fuel leak.
5. Bleed air of the fuel filter. Refer to EC-625.
+Start engine and let it idle for at least one minute after
performing air bleeding.
6. Start the engine, then check that the MI goes off. (If water in
fuel filter sensor is equipped.)
BASIC SERVICE PROCEDUREYD
Fuel Filter (Cont'd)
EC-626

ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
=NJEC0629S02
ItemDIAGNOSTIC TEST MODE
SELF-DIAG
RESULTSDATA MONI-
TORACTIVE TEST
ENGINE CONTROL COMPONENT PARTS
INPUTEngine coolant temperature sensor X X
Vehicle speed sensor X X
Accelerator position sensor X X
Accelerator position switch X X
Crankshaft position sensor (TDC) X X
Ignition switch (start signal) X
Park/Neutral position (PNP) switch (where fitted) X
Battery voltage X X
Mass air flow sensor X X
Stop lamp switch X X
OUTPUTGlow relayXX
EGR volume control valve X X
Cooling fan relay X X X
X: Applicable
SELF-DIAGNOSTIC MODENJEC0629S03Regarding items detected in ªSELF-DIAG RESULTSº mode,
refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-596.
DATA MONITOR MODENJEC0629S04
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
CKPS´RPM (TDC)
[rpm]jj+The engine speed computed from the
crankshaft position sensor (TDC) signal
is displayed.
CMPS´RPM´PUMP
[rpm]jj+The engine speed computed from the
pulse signal sent from electronic control
fuel injection pump is displayed.
COOLAN TEMP/S
[ÉC] or [ÉF]
jj+The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.+When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the
ECM is displayed.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is dis-
played.
FUEL TEMP SEN
[ÉC] or [ÉF]jj+The fuel temperature (sent from elec-
tronic control fuel injection pump) is dis-
played.
ACCEL POS SEN
[V]jj+The accelerator position sensor signal
voltage is displayed.
OFF ACCEL SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
accelerator position switch signal.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD
CONSULT-II (Cont'd)
EC-633

Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
SPILL/V [ÉCA]
j+The control position of spill valve (sent
from electronic control fuel injection
pump) is displayed.
BATTERY VOLT [V]
jj+The power supply voltage of ECM is
displayed.
P/N POSI SW*1
[ON/OFF] (where
fitted)jj+Indicates [ON/OFF] condition from the
park/neutral position switch signal.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is dis-
played regardless of the starter signal.
BRAKE SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
stop lamp switch signal.
BRAKE SW2
[ON/OFF]jj+Indicates [ON/OFF] condition from the
brake pedal position switch signal.
IGN SW
[ON/OFF]jj+Indicates [ON/OFF] condition from igni-
tion switch signal.
MAS AIR/FL SE [V]
jj+The signal voltage of the mass air flow
sensor is displayed.+When the engine is stopped, a certain
value is indicated.
INT/A VOLUME [mg/]+The intake air volume computed from
the mass air flow sensor signal is dis-
played.
F/CUT SIGNAL
[ON/OFF]
j+The [ON/OFF] condition from decelera-
tion fuel cut signal (sent from electronic
control fuel injection pump) is displayed.
OFF´´´Fuel is cut off.
ON´´´Fuel is not cut off.
GLOW RLY
[ON/OFF]j+The glow relay control condition (deter-
mined by ECM according to the input
signal) is displayed.
COOLING FAN
[LOW/HI/OFF]
j+Indicates the control condition of the
cooling fans (determined by ECM
according to the input signal).
+LOW ... Operates at low speed.
HI ... Operates at high speed.
OFF ... Stopped.
BARO SEN [kPa]
jj+The barometric pressure (determined
by the signal voltage from the baromet-
ric pressure sensor built into the ECM)
is displayed.
EGR VOL CON/V
[step]
j+Indicates the EGR volume control value
computed by the ECM according to the
input signals.
+The opening becomes larger as the
value increases.
*1: On models not equipped with park/neutral position (PNP) switch, ªOFFº is always displayed regardless of gear shift position.
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD
CONSULT-II (Cont'd)
EC-634

SEF858S
SEF233G
SEF234G
IntroductionNJEC0630The engine has an ECM to control major systems such as fuel
injection control, fuel injection timing control, glow control system,
etc. The ECM accepts input signals from sensors and instantly
drives electronic control fuel injection pump. It is essential that both
input and output signals are proper and stable. At the same time,
it is important that there are no problems such as vacuum leaks,
or other problems with the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the ªWork Flowº, EC-639.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SEF907L
DIAGNOSTIC WORKSHEETNJEC0630S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
troubleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
EC-637

DESCRIPTION FOR WORK FLOWNJEC0631S01
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using
the ªDIAGNOSTIC WORKSHEETº, EC-637.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC, then erase the
DTC. Refer to EC-627.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
ªSymptom Matrix Chartº will be useful. Refer to EC-646.) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ªDIAGNOSTIC WORK SHEETº is useful to verify the incident. Connect CONSULT-II to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the DTC by driving in (or performing) the ªDTC Confirmation Procedureº. Check and read the DTC
by using CONSULT-II.
During the DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO TRIG)
mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
In case the ªDTC Confirmation Procedureº is not available, perform the ªOverall Function Checkº instead. The
DTC cannot be displayed by this check, however, this simplified ªcheckº is an effective alternative.
The ªNGº result of the ªOverall Function Checkº is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC PXXXX.
If the normal code is indicated, proceed to the Basic Inspection, EC-641. Then perform inspections according to
the Symptom Matrix Chart. Refer to EC-646.
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes.
Inspect the system for mechanical binding, loose connectors or wiring damage using (tracing) ªHarness Layoutsº.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in ªDATA MONITOR
(AUTO TRIG)º mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT-II. Refer to EC-659 or EC-656.
The ªDiagnostic Procedureº in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to GI-24, ªCircuit
Inspectionº.
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENTº, EC-665.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ªDTC Confirmation Procedureº and confirm the normal code (DTC P0000 or 0505) is detected. If the
incident is still detected in the final check, perform STEP VI by using a different method from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) DTC in ECM.
(Refer to EC-627.)
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
Work Flow (Cont'd)
EC-640