2003 NISSAN ALMERA N16 Engine Control

System DiagramNJEC0609
YEC399A
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ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
System Diagram
EC-15

System ChartNJEC0611
Input (Sensor) ECM Function Output (Actuator)
Electronic control fuel injection pump
Crankshaft position sensor (TDC)
Engine coolant temperature sensor
Accelerator position sensor
Accelerator position switch
Park/Neutral position (PNP) switch*
Ignition switch
Battery voltage
Vehicle speed sensor
Air conditioner switch
Mass air flow sensor
Stop lamp switchFuel injection controlElectronic control fuel injection
pump
Fuel injection timing controlElectronic control fuel injection
pump
Fuel cut controlElectronic control fuel injection
pump
Glow control system Glow relay & glow lamp
On board diagnostic system MI (On the instrument panel)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
*: If so equipped
ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
System Chart
EC-16

Fuel Injection Control System
DESCRIPTIONNJEC0612System DescriptionNJEC0612S01Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is compensated to improve engine performance.
Pulse signals are exchanged between ECM and electronic control fuel injection pump (control unit is built-in).
The fuel injection pump control unit performs duty control on the spill valve (built into the fuel injection pump)
according to the input signals to compensate the amount of fuel injected tothe preset value.
Start ControlNJEC0612S02Input/Output Signal ChartNJEC0612S0201
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Ignition switch Start signal
SEF648S
When the ECM receives a start signal from the ignition switch, the ECM adapts the fuel injection system for
the start control. The amount of fuel injected at engine starting is a preset program value in the ECM. The
program is determined by the engine speed and engine coolant temperature.
For better startability under cool engine conditions, the lower the coolant temperature becomes, the greater
the amount of fuel injected. The ECM ends the start control when the engine speed reaches the specific value,
and shifts the control to the normal or idle control.
Idle ControlNJEC0612S03Input/Output Signal ChartNJEC0612S0301
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (Idle con-
trol)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Battery Battery voltage
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
When the ECM determines that the engine speed is at idle, the fuel injectionsystem is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine
to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the
engine coolant temperature signal.
GI
MA
EM
LC
FE
CL
MT
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SU
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ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System
EC-17

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 determinedaccording 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 tosignals 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 themap.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System (Cont’d)
EC-18

Air Conditioning Cut Control
DESCRIPTIONNJEC0614Input/Output Signal ChartNJEC0614S01
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner “ON” 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 “Fuel Injection Control System”, EC-17.
SEF440Z
Crankcase Ventilation System
DESCRIPTIONNJEC0616In this system, blow-by gas is sucked into the air duct after oil
separation by oil separator in the rocker cover.
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ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Air Conditioning Cut Control
EC-19

SEC692
INSPECTIONNJEC0617Ventilation HoseNJEC0617S011. Check hoses and hose connections for leaks.
2. Disconnect all hoses and clean with compressed air. If any
hose cannot be freed of obstructions, replace.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Crankcase Ventilation System (Cont’d)
EC-20

SEF434Z
Spray Pattern TestNJEC0619S051. Check spray pattern by pumping tester handle one full stroke
per second.
NG spray pattern:
Does not inject straight and strong (B in the figure).
Fuel drips (C in the figure).
Does not inject evenly (D in the figure).
2. If the spray pattern is not correct, replace injection nozzle
assembly.
Electronic Control Fuel Injection Pump
REMOVAL AND INSTALLATIONNJEC0620
JEF350Y
RemovalNJEC0620S011. Remove the parts shown below.
Engine hood
Engine coolant (drain)
Engine cover
Heater pipe under intake manifold
Injection tubes
Right splash cover (with undercover)
Right front wheel
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BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont’d)
EC-25

JEF351Y
2. Disconnect the fuel hoses from the fuel injection pump.
3. Disconnect the harness connector from the fuel injection
pump.
Disconnect the connector by pulling the connector stopper
fully.
When the stopper is fully pulled, the connector will be discon-
nected together. For installation, push the connector half way
first, then press the stopper until it locks, so that the connec-
tor is connected together.
4. Remove the fuel injection pump rear bracket.
JEF352Y
5. Remove the front chain case.
Move the power steering fluid reservoir tank from the bracket.
Loosen and remove the mounting bolts in the reverse order of
the numbers shown in the figure.
As for bolts 6, 10, and 11, remove with rubber washer because
there is not enough space for removing only the bolts.
CAUTION:
To prevent foreign objects from getting in the engine, cover
the opening during the removal of the front chain case.
JEF353Y
6. Adjust the No. 1 cylinder to the top dead center position.
Turn the crankshaft pulley clockwise, then align the alignment
mark (punched mark) of the camshaft sprocket to the position
shown in the figure.
There is no indicator on the crankshaft pulley.
It is not necessary to mark the secondary timing chain for
removal because it can be matched by the link color for instal-
lation. However, the alignment mark on the fuel injection pump
sprocket is difficult to see; mark it if necessary.
JEF354Y
7. Remove the chain tensioner.
a. Push the plunger of the chain tensioner, then fix it with a tool
such as a push pin.
JEF355Y
b. Using the hexagon wrench (face to face: 5 mm) (SST), remove
the mounting bolts, then remove the chain tensioner.
A multi-purpose tool may also be used.
BASIC SERVICE PROCEDUREYD
Electronic Control Fuel Injection Pump (Cont’d)
EC-26