2002 NISSAN TERRANO Service Repair Manual

MEC029E
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
Engine Control Component Parts Location
(Cont'd)
EC-15

Circuit Diagram
YEC170A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
EC-16

System Diagram
SEC390D
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
EC-17

Vacuum Hose Drawing
1. Swirl control valve control solenoid
valve to swirl control valve actua-
tor
2. Intake air control valve control
solenoid valve to intake air control
valve actuator3. Variable nozzle turbocharger con-
trol actuator to vacuum damper
4. Variable nozzle turbocharger con-
trol solenoid valve to resonator5. Variable nozzle turbocharger con-
trol solenoid valve to vacuum
pump
Refer to ªSystem Diagramº, EC-17 for vacuum control system.
MEC030E
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
EC-18

System Chart
Input (Sensor) ECM Function Output (Actuator)
IElectronic control fuel injection pump
ICrankshaft position sensor (TDC)
IEngine coolant temperature sensor
IAccelerator position sensor
IAccelerator position switch
IAccelerator switch (F/C)
IPark/Neutral position (PNP) switch
IIgnition switch
IBattery voltage
IVehicle speed sensor
IAir conditioner switch
IMass air flow sensor
IStop lamp switch
IHeat up switch
ICharge air pressure sensor*1Fuel injection control Electronic control fuel injection pump
Fuel injection timing control Electronic control fuel injection pump
Fuel cut control Electronic control fuel injection pump
Glow control system Glow relay & glow lamp
On board diagnostic system MIL (On the instrument panel)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
Variable nozzle turbocharger control Variable nozzle turbocharger control sole-
noid valve
Swirl control valve control Swirl control valve control solenoid valve
Intake air control valve control Intake air control valve control solenoid
valve
*1: This sensor is not used to control the engine system under normal conditions.
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
EC-19

Fuel Injection Control System
DESCRIPTION
System description
Three 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 to the preset value.
Start control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection con-
trol (start control)Electronic control fuel injec-
tion pump Crankshaft position sensor (TDC) Engine speed
Ignition switch Start signal
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 control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection con-
trol (Idle control)Electronic control fuel injec-
tion pump Crankshaft position sensor (TDC) Engine speed
Park/Neutral position (PNP) switch Gear position
Battery Battery voltage
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
Heat up switch Heat up switch signal
When the ECM determines that the engine speed is at idle, the fuel injection system 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 and heat up switch signal.
SEF648S
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTIONZD30DDTi
EC-20

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 positionFuel 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
DESCRIPTIONZD30DDTi
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 ªONº signal
Air conditioner cut
controlAir conditioner relay Accelerator position sensorAccelerator 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 controlElectronic 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 ªFuel Injection Control Systemº, EC-20.
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTIONZD30DDTi
EC-22