Nissan Terrano r20e. Manual — part 96
Normal control
Input/output signal chart
Sensor
Input Signal to ECM
ECM Function
Actuator
Crankshaft position sensor (TDC)
Engine speed
Fuel injection con-
trol (Normal con-
trol)
Electronic control fuel injec-
tion pump
Accelerator position sensor
Accelerator position
Vehicle speed sensor
Vehicle speed
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 accelerator position. These sensors send signals to
the ECM.
The fuel injection data, predetermined by correlation between vari-
ous 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 compari-
son with the map.
Maximum amount control
Input/output signal chart
Sensor
Input Signal to ECM
ECM Function
Actuator
Mass air flow sensor
Amount of intake air
Fuel injection con-
trol (Maximum
amount control)
Electronic control fuel injec-
tion pump
Engine coolant 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 control
Input/output signal chart
Sensor
Input Signal to ECM
ECM Function
Actuator
Accelerator switch (F/C)
Accelerator position
Fuel injection con-
trol (Deceleration
control)
Electronic control fuel injec-
tion 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 switch
(F/C) and crankshaft position sensor (TDC).
SEF649S
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
ZD30DDTi
Fuel Injection Control System (Cont’d)
EC-21
Fuel Injection Timing Control System
DESCRIPTION
The 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.
Air Conditioning Cut Control
DESCRIPTION
Input/output signal chart
Sensor
Input Signal to ECM
ECM Function
Actuator
Air conditioner switch
Air conditioner “ON” signal
Air conditioner cut
control
Air conditioner relay
Accelerator position sensor
Accelerator valve opening
angle
Vehicle speed sensor
Vehicle speed
Engine coolant temperature sensor
Engine coolant temperature
System description
This 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)
DESCRIPTION
Input/output signal chart
Sensor
Input Signal to ECM
ECM Function
Actuator
Vehicle speed sensor
Vehicle speed
Fuel cut control
Electronic control fuel injec-
tion pump
Park/Neutral position (PNP) switch
Neutral position
Accelerator position switch or Accelerator
switch (F/C)
Accelerator position
Engine coolant temperature sensor
Engine coolant temperature
Crankshaft position sensor (TDC)
Engine speed
If the engine speed is above 2,700 rpm with no load (for example, in neutral and engine speed over 2,700
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-20.
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
ZD30DDTi
EC-22
Crankcase Ventilation System
DESCRIPTION
In this system, blow-by gas is sucked into the air inlet pipe after oil
separation by oil separator in the rocker cover.
INSPECTION
Ventilation hose
1. 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.
JEF224Z
SEC692
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
ZD30DDTi
EC-23
Injection Tube and Injection Nozzle
REMOVAL AND INSTALLATION
CAUTION:
I
Do not disassemble injection nozzle assembly. If NG,
replace injection nozzle assembly.
I
Plug flare nut with a cap or rag so that no dust enters the
nozzle. Cover nozzle tip for protection of needle.
Injection tube
Removal
1. Mark the cylinder Nos. to the injection tubes, then disconnect
them.
I
Marking should be made at proper locations and by the
proper method, so that they are not erased by fuel, etc.
2. Remove the clamps, then disconnect the tubes one by one.
I
Avoid letting leaked fuel get on the interior walls of the
engine compartment.
Take special care to prevent fuel from getting on the engine
mount insulator.
JEF237Z
JEF238Z
BASIC SERVICE PROCEDURE
ZD30DDTi
EC-24
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