sensor NISSAN PRIMERA 1999 Electronic Repair Manual

SEF189X Intake manifold
collectorFuel pressure
regulatorHeadlamp
(Left side)
Front
Refrigerant
pressure sensor and
harness connector
Power transistorTerminal for ignition coil
Camshaft position sensor,
power transistor and ignition
coil (built into distributor)
Terminal for camshaft position sensor
and power transistor Camshaft position
sensor
Metal tip of ignition coil tower
(Terminal of coil circuit)
NOTE: Power transistor, camshaft position sensor,
and ignition coil have to be replaced as a
distributor assembly.
ENGINE AND EMISSION CONTROL OVERALL SYSTEMSR20DE
Engine Control Component Parts Location (Cont'd)
EC-18

System ChartNCEC0013
Input (Sensor) ECM Function Output (Actuator)
ICamshaft position sensor
IMass air flow sensor
IEngine coolant temperature sensor
IHeated oxygen sensor 1 (front)
IIgnition switch
IThrottle position sensor
IPNP switch
IAir conditioner switch
IKnock sensor
ICrankshaft position sensor (OBD)*1
IBattery voltage
IPower steering oil pressure switch
IVehicle speed sensor or ABS actuator and
electric unit (control unit)
IIntake air temperature sensor
IHeated oxygen sensor 2 (rear)*2
ITCM (Transmission control module)*3
IClosed throttle position switch
IElectrical load
IRefrigerant pressure sensorFuel injection & mixture ratio control Injectors
Distributor ignition system Power transistor
Idle air control system IACV-AAC valve
Fuel pump control Fuel pump relay
Heated oxygen sensor 1 (front) monitor &
on board diagnostic systemMalfunction indicator
(On the instrument panel)
Heated oxygen sensor1&2(front & rear)
heater controlHeated oxygen sensor1&2
heater (front & rear)
EVAP canister purge flow controlEVAP canister purge volume con-
trol solenoid valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
*1: These sensors are not used to control the engine system. They are used only for the on board diagnosis.
*2: Under normal conditions, this sensor is not for engine control operation.
*3: The DTC related to CVT will be sent to ECM.
ENGINE AND EMISSION CONTROL OVERALL SYSTEMSR20DE
System Chart
EC-22

Multiport Fuel Injection (MFI) System
DESCRIPTIONNCEC0014Input/Output Signal ChartNCEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Fuel injec-
tion & mix-
ture ratio
controlInjector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Electrical load Electrical load signal
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNCEC0014S02The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNCEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.

IDuring warm-up
IWhen starting the engine
IDuring acceleration
IHot-engine operation
IWhen selector lever is changed from ªNº to ªDº (CVT models only)
IHigh-load, high-speed operation

IDuring deceleration
IDuring high engine speed operation
IDuring high vehicle speed operation (M/T models)
IExtremely high engine coolant temperature
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Multiport Fuel Injection (MFI) System
EC-23

Mixture Ratio Feedback Control (Closed loop control)NCEC0014S04
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission con-
trol. The three way catalyst can then better reduce CO, HC and NOx emissions. This system uses a heated
oxygen sensor 1 (front) in the exhaust manifold to monitor if the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about the heated
oxygen sensor 1 (front), refer to EC-SR-144. This maintains the mixture ratio within the range of stoichiomet-
ric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 (rear) is located downstream of the three way catalyst. Even if the switching char-
acteristics of the heated oxygen sensor 1 (front) shift, the air-fuel ratio is controlled to stoichiometric by the
signal from the heated oxygen sensor 2 (rear).
Open Loop ControlNCEC0014S05The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
IDeceleration and acceleration
IHigh-load, high-speed operation
IMalfunction of heated oxygen sensor 1 (front) or its circuit
IInsufficient activation of heated oxygen sensor 1 (front) at low engine coolant temperature
IHigh engine coolant temperature
IDuring warm-up
IWhen starting the engine
Mixture Ratio Self-learning ControlNCEC0014S06The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxy-
gen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio
as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily con-
trolled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot film) and charac-
teristic changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This
is then computed in terms of ªinjection pulse durationº to automatically compensate for the difference between
the two ratios.
ªFuel trimº refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
ªShort term fuel trimº is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from the heated oxygen sensor 1 (front) indicates whether the mixture ratio is RICH or LEAN
compared to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is
rich, and an increase in fuel volume if it is lean.
ªLong term fuel trimº is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
SEF336WA
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Multiport Fuel Injection (MFI) System (Cont'd)
EC-24

Fuel Injection TimingNCEC0014S07
Two types of systems are used.
Sequential Multiport Fuel Injection System
NCEC0014S0701Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
NCEC0014S0702Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
Fuel Shut-offNCEC0014S08Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Distributor Ignition (DI) System
DESCRIPTIONNCEC0015Input/Output Signal ChartNCEC0015S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Ignition tim-
ing controlPower transistor Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensorThrottle position
Throttle valve idle position
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Ignition switch Start signal
Knock sensor Engine knocking
PNP switch Gear position
Battery Battery voltage
SEF337W
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Multiport Fuel Injection (MFI) System (Cont'd)
EC-25

System DescriptionNCEC0015S02
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of
the engine. The ignition timing data is stored in the ECM. This data forms the map shown above.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Com-
puting this information, ignition signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
AÉBTDC
During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.
IAt starting
IDuring warm-up
IAt idle
IAt low battery voltage
IDuring acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions.
If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The
ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut Control
DESCRIPTIONNCEC0016Input/Output Signal ChartNCEC0016S01
Sensor Input Signal to ECMECM func-
tionActuator
Air conditioner switch Air conditioner ªONº signal
Air condi-
tioner cut
controlAir conditioner relay PNP switch Neutral position
Throttle position sensor Throttle valve opening angle
Camshaft position sensor Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Power steering oil pressure switch Power steering operation
System DescriptionNCEC0016S02This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
IWhen the accelerator pedal is fully depressed.
IWhen cranking the engine.
SEF742M
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Distributor Ignition (DI) System (Cont'd)
EC-26

IAt high engine speeds.
IWhen the engine coolant temperature becomes excessively high.
IWhen operating power steering during low engine speed or low vehicle speed.
IWhen engine speed is excessively low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNCEC0017Input/Output Signal ChartNCEC0017S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Fuel cut
controlInjectors PNP switch Neutral position
Throttle position sensor Throttle position
Engine coolant temperature sensor Engine coolant temperature
Camshaft position sensor Engine speed
If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
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 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªMultiport Fuel Injection (MFI) Systemº,
EC-SR-23.
Evaporative Emission System
DESCRIPTIONNCEC0018
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating.
EVAP canister purge volume control solenoid valve is controlled by ECM. When the engine operates, the flow
Intake manifold
Throttle body
Purge line
EVAP canister
purge volume
control solenoid
valve
Relief of vacuum
Sealing gas cap with
pressure relief valve
and vacuum relief
valve
Fuel tankAir
Fuel vapor EVAP
canister
SEF916W
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Air Conditioning Cut Control (Cont'd)
EC-27

Overall Inspection SequenceNCEC0028S0101
*: Refer to EC-SR-46.
SEF104X INSPECTION
Perform diagnostic test mode II
(Self-diagnostic results).Repair or replace. NG
Check ignition timing and idle
speed.
Idle air volume learning.*
COMPLETE
INCOMPLETE
Find reason for incompleteness,
and remove.* OK
Check heated oxygen sensor 1 (front)
function.NG
Check heated oxygen sensor 1 (front)
harness.NG
OK
Check CO%.
NGOK
INSPECTION ENDCheck emission control parts and
repair or replace if necessary.NGRepair or replace harness.
Replace front heated oxygen
sensor.
Check front heated oxygen
sensor function.OK H
BASIC SERVICE PROCEDURESR20DE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-35

INSPECTION PROCEDURENCEC0028S02
1 INSPECTION START
1. Visually check the following:
IAir cleaner clogging
IHoses and duct for leaks
IElectrical connectors
IGasket (intake manifold, cylinder head, exhaust system)
IThrottle valve and throttle position sensor operation
2. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.
Ensure engine speed stays below 1,000 rpm.
SEF935W3. Open engine hood and run engine at about 2,000 rpm for about 2 minutes under no-load.
4. Perform the Diagnostic Test Mode II (Self-diagnostic results). Refer to EC-SR-61.
SAT652J
OK or NG
OK©IGO TO 2. (With CONSULT-II)
IGO TO 3. (Without CONSULT-II)
NG©1. Repair or replace components as necessary.
2. GO TO 2. (With CONSULT-II)
3. GO TO 3. (Without CONSULT-II)
BASIC SERVICE PROCEDURESR20DE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-36

3 CHECK IGNITION TIMING
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Rev engine two or three times under no-load, then run engine at idle speed for about 1 minute.
SEF978U3. Turn off engine and disconnect throttle position sensor harness connector (CVT models only).
SEF197X4. Start engine and rev it (2,000 to 3,000 rpm) two or three times under no-load, then run engine at idle speed.
5. Check ignition timing with a timing light.
AEC80415É 2É BTDC
(in ªPº or ªNº position for CVT)
OK or NG
OK©GO TO 5.
NG©1. Perform ªIdle air volume learningº. Refer to EC-SR-46.
2. If still NG, GO TO 4.
Throttle position
sensor harness
connector Throttle body
Closed throttle position switch
harness connector (CVT
models)
BTDC
White painting
BASIC SERVICE PROCEDURESR20DE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-38